Biology:Megestrol acetate

From HandWiki
Short description: Pharmaceutical drug
Megestrol acetate
Megestrol acetate.svg
Megestrol acetate molecule ball.png
Clinical data
Trade namesMegace, others
Other namesMGA; BDH-1298; NSC-71423; SC-10363; 17α-Acetoxy-6-dehydro-6-methylprogesterone; 17α-Acetoxy-6-methylpregna-4,6-diene-3,20-dione
License data
Routes of
administration
By mouth
Drug classProgestogen; Progestin; Progestogen ester; Antigonadotropin; Steroidal antiandrogen
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability100%[2]
MetabolismLiver (hydroxylation, reduction, conjugation)[4]
Elimination half-lifeMean: 34 hours[3]
Range: 13–105 hours[3]
ExcretionUrine: 57–78%[4]
Feces: 8–30%[4]
Identifiers
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
Chemical and physical data
FormulaC24H32O4
Molar mass384.516 g·mol−1
3D model (JSmol)

Megestrol acetate (MGA), sold under the brand name Megace among others, is a progestin medication which is used mainly as an appetite stimulant to treat wasting syndromes such as cachexia.[2][3][5][1] It is also used to treat breast cancer and endometrial cancer, and has been used in birth control.[3][5][6][7] Megestrol acetate is generally formulated alone, although it has been combined with estrogens in birth control formulations.[8] It is usually taken by mouth.[2]

Side effects of megestrol acetate include increased appetite, weight gain, vaginal bleeding, nausea, edema, low sex hormone levels, sexual dysfunction, osteoporosis, cardiovascular complications, glucocorticoid effects, and others.[5] Megestrol acetate is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone.[2] It has weak partial androgenic activity, weak glucocorticoid activity, and no other important hormonal activity.[2] Due to its progestogenic activity, megestrol acetate has antigonadotropic effects.[5] The mechanism of action of the appetite stimulant effects of megestrol acetate is unknown.[9][10][11]

Megestrol acetate was discovered in 1959 and was introduced for medical use, specifically in birth control pills, in 1963.[6][7][12] It may be considered a "first-generation" progestin.[13] The medication was withdrawn in some countries in 1970 due to concerns about mammary toxicity observed in dogs, but this turned out not to apply to humans.[14][15][16][17][18] Megestrol acetate was approved for the treatment of endometrial cancer in 1971 and wasting syndromes in 1993.[5][19] It is marketed widely throughout the world.[20][21] It is available as a generic medication.[22]


Medical uses

Megestrol acetate is used mainly as an appetite stimulant to promote weight gain in a variety of situations.[23][24][25] When given at very high dosages, it can substantially increase appetite in most individuals, even those with advanced cancer, and is often used to boost appetite and induce weight gain in patients with cancer or HIV/AIDS-associated cachexia.[23] In addition to its effects on appetite, megestrol acetate appears to have antiemetic effects.[26][27] Megestrol acetate is also used as an antineoplastic agent in the treatment of breast cancer and endometrial cancer.[23][28] It is significantly inferior to aromatase inhibitors in both clinical effectiveness and tolerability as a second-line therapy for breast cancer after tamoxifen failure.[29] Megestrol acetate was formerly used in combined oral contraceptives in combination with ethinylestradiol or mestranol,[6][7][30] and has been used in a combined injectable contraceptive in combination with estradiol as well.[31]

Although it has not been approved for these uses, megestrol acetate has been studied and/or used off-label for a variety of indications including menopausal hormone therapy[32][33][34] and the treatment of hot flashes,[35][36][37][38] gynecological/menstrual disorders,[39][40] endometriosis,[41] endometrial hyperplasia,[42] ovarian cancer,[43][44][45][46] prostate cancer,[47][48][49][50][51][52][53] benign prostatic hyperplasia,[54][55] male breast cancer,[56] and precocious puberty.[4][5][57] Megestrol acetate can also be used to treat pattern hair loss in men, but its side effects generally make it unacceptable for this purpose.[58]

Appetite stimulation is achieved with megestrol acetate with oral dosages of 400 to 800 mg/day.[59] The optimal dosage with maximum effect for appetite stimulation has been determined to be 800 mg/day.[60]

Available forms

Megestrol acetate is available as 5 mg, 20 mg, and 40 mg oral tablets and in oral suspensions of 40 mg/mL, 125 mg/mL, 625 mg/5 mL, and 820 mg/20 mL.[59][61] It was used at doses of 1 mg, 2 mg, 4 mg, and 5 mg in combined oral contraceptives.[6][7][30][31] Megestrol acetate is formulated at a dose of 25 mg in combination with a dose of 3.75 mg estradiol in a microcrystalline aqueous suspension for use as a once-monthly combined injectable contraceptive in women.[31]

Contraindications

Contraindications of megestrol acetate include hypersensitivity to megestrol acetate or any component of its formulation, known or suspected pregnancy, and breastfeeding.[1] Megestrol acetate is a teratogen in animals and may have the potential to cause fetal harm, such as decreased fetal weight and feminization of male fetuses.[1]

Side effects

The most common side effect of megestrol acetate is weight gain, with an incidence of 15–70% at the high dosages used to treat breast cancer.[3][4] Other side effects include vaginal bleeding (7–8%), nausea (7%), and edema (5%), as well as others such as dizziness and shortness of breath.[3][4][62] Megestrol acetate can cause hypogonadism and associated symptoms like diminished secondary sexual characteristics, sexual dysfunction, osteoporosis, and reversible infertility in men and premenopausal women.[63][64][65] Combining megestrol acetate with an androgen/anabolic steroid like oxandrolone, nandrolone decanoate, or testosterone in men can alleviate megestrol acetate-associated symptoms of hypoandrogenism as well as further increase appetite and weight gain.[64][66][67][68] Less common but more serious side effects of megestrol acetate include cardiovascular/thromboembolic complications such as thrombophlebitis.[3] It may also cause glucocorticoid side effects such as Cushing syndrome-like symptoms, steroid diabetes, and adrenal insufficiency at high dosages.[69][70][71] Case reports of deep vein thrombosis, pulmonary embolism, jaundice, intrahepatic cholestasis, and meningiomas in association with high-dosage megestrol acetate have been published.[72][73][74][75] In older patients who take megestrol acetate, one in 23 will have an adverse event leading to death.[76]

Overdose

Megestrol acetate has been studied at very high dosages of as much as 1,600 mg/day with no serious adverse effects observed.[1][77] No clear increase in rate or severity of side effects have been observed up to 1,600 mg/day megestrol acetate except for weight gain, mild increases in blood pressure, and some fluid retention.[77] In post-marketing experience, limited reports of overdose have been received.[1] Signs and symptoms described in these reports have included diarrhea, nausea, abdominal pain, shortness of breath, cough, unsteady gait, listlessness, and chest pain.[1] There is no specific antidote for overdose of megestrol acetate.[1] Treatment should be supportive and based on symptoms.[1] Megestrol acetate has not been assessed for dialyzability.[1] However, due to its low solubility, it is thought that dialysis would not be useful for treating megestrol acetate overdose.[1]

Interactions

Interactions of megestrol acetate include significantly decreased exposure to indinavir, which may necessitate an increased dosage of the medication.[1] When megestrol acetate is co-administered with zidovudine and rifabutin, there is no significant change in exposure to these medications and no dosage adjustment is necessary.[1]

Pharmacology

Pharmacodynamics

Megestrol acetate has progestogenic activity, antigonadotropic effects, weak partial androgenic activity, and weak glucocorticoid activity.[2][78][79]

Relative affinities (%) of megestrol acetate
Compound PR AR ER GR MR SHBG CBG
Megestrol acetate 65 5 0 30 0 0 0
Notes: Values are percentages (%). Reference ligands (100%) were promegestone for the PR, metribolone for the AR, estradiol for the ER, dexamethasone for the GR, aldosterone for the MR, dihydrotestosterone for SHBG, and cortisol for CBG. Sources:[2][78][79]

Progestogenic activity

Megestrol acetate is a progestogen, or an agonist of the progesterone receptor (PR).[2][79][80] It has about 65% of the affinity of promegestone and 130% of the affinity of progesterone for the progesterone receptor.[79][80] Like other progestogens, megestrol acetate has functional antiestrogenic effects in certain tissues such as the endometrium and has antigonadotropic effects.[2][23][81] The total endometrial transformation dose of megestrol acetate is 50 mg per cycle.[81]


Antigonadotropic and anticorticotropic effects

Megestrol acetate has antigonadotropic effects in humans at sufficient doses, capable of profoundly suppressing circulating androgen and estrogen concentrations.[23][50][82][83][84][85] The antigonadotropic effects of megestrol acetate are the result of activation of the progesterone receptor, which suppresses the secretion of the gonadotropins—peptide hormones responsible for signaling the body to produce not only progesterone but also the androgens and the estrogens—from the pituitary gland as a form of negative feedback inhibition, and hence downregulates the hypothalamic–pituitary–gonadal axis (HPG axis), resulting in decreased levels of the sex hormones and interference with fertility.[86] As such, megestrol acetate has functional antiandrogenic and antiestrogenic effects as well as contraceptive effects via its antigonadotropic effects.[5]

The precise ovulation-inhibiting dosage of megestrol acetate is unknown.[81][87] However, doses of 1 to 5 mg megestrol acetate were previously used in combined birth control pills in combination with the estrogen ethinylestradiol or mestranol.[6][7][30] Megestrol acetate is an effective contraceptive by itself at dosages of 0.35 to 0.5 mg/day, but is not effective at a dosage of 0.25 mg/day.[5] Megestrol acetate alone does not inhibit ovulation at a dosage of 0.5 mg/day, nor does it fully inhibit ovulation at a dosage of 0.7 mg/day or even at a dosage of 5 mg/day.[5][39][88] The combination of 2 to 5 mg/day megestrol acetate and 100 μg/day mestranol has been found to consistently inhibit ovulation, whereas either medication alone did not completely inhibit ovulation in all women.[39][89]

Suppression of testosterone levels by megestrol acetate is responsible for its effectiveness in the treatment of conditions like prostate cancer and benign prostatic hyperplasia.[5][90] In one study, 120 to 160 mg/day megestrol acetate suppressed testosterone levels in men by 72%.[84] However, a recovery or "escape" of testosterone levels, gradually returning to near-normal values, has been observed in most men after 2 to 6 months of megestrol acetate therapy, and this has limited the usefulness of the medication.[23][91][92][93] The combination of a lower dosage of megestrol acetate (40–80 mg/day) and a low oral dosage of an estrogen such as estradiol (0.5–1.5 mg/day), diethylstilbestrol (0.1–0.2 mg/day) or ethinylestradiol (50 µg/day) is able to suppress testosterone levels into the castrate range in men, maintain this suppression long-term, and achieve equivalent effectiveness to high-dosage estrogen monotherapy in the treatment of prostate cancer with comparatively greatly reduced toxicity and side effects.[5][23][50][51][91][94][95][96][97] In spite of these results, however, this combination has been very rarely used to treat prostate cancer in the United States.[91]

The antigonadotropic as well as anticorticotropic effects of megestrol acetate may be involved in its effectiveness in the treatment of postmenopausal breast cancer via substantially decreasing gonadal and adrenal production of sex steroids and by extension circulating levels of estrogens, by about 80%.[98][99][100]

Androgenic and antiandrogenic activity

Megestrol acetate is a weak partial agonist of the androgen receptor (AR).[101][102][103] It has been reported to bind to this receptor with 5% of the affinity of the anabolic steroid metribolone.[2][78][79] Despite its weak intrinsic activity at the androgen receptor, at clinical doses in humans, megestrol acetate appears to behave, for all intents and purposes, purely as an antiandrogen.[104] This is based on the fact that no virilizing side effects have been observed with the use of megestrol acetate in patients of either sex at dosages up to as high as 1,600 mg per day, the highest that has been assessed.[104] Furthermore, megestrol acetate produces detectable androgenic effects in animals only at a dose that is the equivalent of approximately 200 times that typically used for the treatment of prostate cancer in men.[105] However, the medication does have moderate androgenic effects on serum lipids in humans, causing a significant reduction of HDL and LDL cholesterol levels and no change in triglyceride levels at a dosage of only 5 mg/day.[2] Conversely, megestrol acetate does not decrease sex hormone-binding globulin levels.[106] The weak but significant androgenic activity of megestrol acetate may serve to limit its clinical effectiveness in the treatment of prostate cancer.[102][103][107][108]

Glucocorticoid activity

Megestrol acetate is an agonist of the glucocorticoid receptor (GR), the biological target of glucocorticoids like cortisol.[2][78][79] It has been found to possess 30% of the affinity of the corticosteroid dexamethasone for this receptor.[2][78][79] Megestrol acetate shows the lowest ratio of progesterone receptor affinity to glucocorticoid receptor affinity of a broad selection of marketed progestins, suggesting that it may have among the highest relative glucocorticoid effect of the progestins used in medicine.[2] Megestrol acetate produces observable glucocorticoid effects, with one study finding that, in the dose range tested, it possessed about 50% of the eosinopenic and hyperglycemic activity (markers of glucocorticoid activity) of an equal amount of medroxyprogesterone acetate and about 25% that of hydrocortisone.[109] Accordingly, manifestations of its glucocorticoid activity, including symptoms of Cushing's syndrome, steroid diabetes, and adrenal insufficiency, have been reported with the use of megestrol acetate in the literature, albeit sporadically.[69]

Appetite stimulation

Megestrol acetate is frequently used as an appetite stimulant to promote weight gain.[23][24][25] The direct mechanism of appetite enhancement is unclear, but it is known that megestrol acetate induces a variety of downstream changes to cause the effect, including stimulation of the release of neuropeptide Y in the hypothalamus, neurosteroid-like modulation of calcium channels in the ventromedial hypothalamus,[110] and inhibition of the secretion of proinflammatory cytokines including interleukin 1α, interleukin 1β, interleukin 6, and tumor necrosis factor α, all of which have been implicated in facilitation of appetite.[9][10][11] Increased levels of insulin-like growth factor 1 (IGF-1) may also be involved, specifically in its anabolic effects.[111] Studies of megestrol acetate in elderly patients who experience weight loss are limited and of poor quality with most showing minimal or no weight gain, with no nutritional or clinically significant beneficial outcomes observed. In patients who take megestrol acetate, one in 12 will have an increase in weight.[76]

Miscellaneous

Unlike the case of the androgen receptor, megestrol acetate has no significant affinity for the estrogen receptor.[2][78][79] As such, it does not possess the capacity to directly activate the estrogen receptor.[2][78][79] Furthermore, unlike antiandrogens such as spironolactone and bicalutamide but similarly to cyproterone acetate, there is relatively little risk of indirectly mediated estrogenic side effects (e.g., gynecomastia) with megestrol acetate.[112] This is because megestrol acetate strongly suppresses both androgen and estrogen levels at the same time.[23][50][82][83][84][85] Similarly to the case of the estrogen receptor, megestrol acetate has negligible affinity for the mineralocorticoid receptor (MR), and hence does not possess mineralocorticoid or antimineralocorticoid activity.[2][78][79]

Megestrol acetate has been found to dose-dependently increase total and free IGF-1 levels up to a dosage of 120 mg/day.[111] Total IGF-1 levels were described as "profoundly" increased, gradually increasing, significantly by 3 days of treatment, up to a maximum of 2.66-fold by 5 to 6 months of treatment.[111] Free (readily dissociable) concentrations of IGF-1 were increased to a smaller extent, by 1.23–2.15-fold, and were described as increasing "moderately".[111] It was suggested that the increase in IGF-1 levels with high-dosage megestrol acetate therapy may explain the anabolic effects of megestrol acetate in patients with cachexia.[111]

Pharmacokinetics

The oral bioavailability of megestrol acetate is approximately 100%.[2] After a single low oral dose of 4 mg megestrol acetate, peak serum concentrations of megestrol acetate were about 7 ng/dL (18 nmol/L) and occurred after 3 hours.[2] Following a single high oral dose of 160 mg micronized megestrol acetate in men, peak circulating levels of megestrol acetate were 125 ng/mL (325 nmol/L) and occurred after 6.3 hours.[113][114][115] This study found that micronized megestrol acetate at this dose showed considerably improved absorption relative to its conventional tablet form.[113][114][115] In terms of plasma protein binding, megestrol acetate is bound mostly to albumin (82.4%) and is not bound to sex hormone-binding globulin or to corticosteroid-binding globulin.[2][116][78] Megestrol acetate metabolized in the liver mainly by hydroxylation of the C21, C2α, and C6 positions, as well as by reduction and conjugation.[2][4] Its elimination half-life is 34 hours on average, with a range of 13 to 105 hours.[3] Megestrol acetate is excreted 57 to 78% in urine and 8 to 30% in feces.[4]

At high doses, megestrol acetate appears to have far greater bioavailability and potency than medroxyprogesterone acetate, regardless of whether the route of administration of the latter is oral or parenteral.[4][117][118] Following oral administration of 80 to 160 mg megestrol acetate or 500 to 1,000 mg medroxyprogesterone acetate, circulating levels of megestrol acetate were 2- to 10-fold higher than those of medroxyprogesterone acetate.[4][117][118] Similar findings have been found for oral megestrol acetate relative to medroxyprogesterone acetate administered via intramuscular injection.[4] Megestrol acetate also reaches steady-state levels more quickly than medroxyprogesterone acetate.[118] The improved potency of megestrol acetate compared to medroxyprogesterone acetate may be due to increased resistance to metabolism of megestrol acetate afforded by its C6(7) double bond (medroxyprogesterone acetate being identical to megestrol acetate in structure except lacking this feature).[4][119][120]

The pharmacokinetics of megestrol acetate have been reviewed.[2][81][121]

Chemistry

Megestrol acetate, also known as 17α-acetoxy-6-dehydro-6-methylprogesterone or as 17α-acetoxy-6-methylpregna-4,6-diene-3,20-dione, is a synthetic pregnane steroid and a derivative of progesterone.[20][122] It is specifically a derivative of 17α-hydroxyprogesterone with a methyl group at the C6 position, a double bond between the C6 and C7 positions, and an acetate ester at the C17α position.[20][122] Megestrol acetate is the C17α acetate ester of megestrol, which, in contrast to megestrol acetate, was never marketed.[20][122] Analogues of megestrol acetate include other 17α-hydroxyprogesterone derivatives such as acetomepregenol, anagestone acetate, chlormadinone acetate, cyproterone acetate, hydroxyprogesterone caproate, medroxyprogesterone acetate, and nomegestrol acetate.[20][122] Megestrol acetate differs from medroxyprogesterone acetate only by its C6(7) double bond.[123] Close analogues of megestrol acetate that were never marketed include cymegesolate (megestrol acetate 3β-cypionate) and megestrol caproate.[124][125][126]

Synthesis

Chemical syntheses of megestrol acetate have been published.[127][128]

History

Megestrol acetate was synthesized at Syntex in 1959.[81] It was derived from medroxyprogesterone acetate, which had been synthesized at Syntex in 1957.[12][81] Megestrol acetate was the third synthetic derivative of progesterone to be developed for use as a medication, following hydroxyprogesterone caproate in 1954 and medroxyprogesterone acetate in 1957.[81] The medication was introduced for medical use in combination with ethinylestradiol (EE) as an oral contraceptive in 1963 by British Drug Houses in the United Kingdom under the brand name Volidan (4 mg MGA and 50 μg EE tablets),[6][7] and this was followed by Serial 28 (1 mg MGA and 100 μg EE tablets) and Volidan 21 (4 mg MGA and 50 μg EE tablets) in 1964 and Nuvacon (2 mg MGA and 100 μg EE tablets) in 1967, all by British Drug Houses also in the United Kingdom.[30] It was also marketed under the brand name Delpregnin (5 mg MGA and 100 μg mestranol tablets) by 1965, among others.[117][129][130][131] Megestrol acetate-containing birth control pills were withdrawn after reports in the early 1970s of a high incidence of venous thromboembolism with the preparations.[106]

In the early 1970s, megestrol acetate was found to be associated with mammary tumors in beagle dogs, and along with several other progestogens, was withdrawn as an oral contraceptive from several markets including the United Kingdom, Canada, and West Germany.[14][15][16] It was also under investigation for use as a contraceptive in the United States, but development was discontinued in 1972 following the mammary toxicity findings in dogs, and megestrol acetate was never marketed as an oral contraceptive in the United States.[16][17][132] Subsequent research, such as monkey studies, revealed that there is no similar risk in humans.[4][18] Following its withdrawal from the market, megestrol acetate was eventually reintroduced for the treatment of hormone-sensitive cancers.[132] In addition, megestrol acetate was marketed for veterinary use in dogs in 1969 in the United Kingdom and in 1974 in the United States.[133][134][135]

Progesterone was first found to be effective in the treatment of endometrial hyperplasia in 1951,[4] and progestins were first found to be effective in the treatment of endometrial cancer in 1959.[136] Megestrol acetate was reported to be effective in the treatment of endometrial hyperplasia in the mid-1960s.[4] It first started to be studied as a treatment for endometrial cancer in 1967, with findings published in 1973.[4][137][138] Megestrol acetate was reportedly introduced for the treatment of endometrial cancer in the United States in 1971.[5] Progesterone was studied in the treatment of breast cancer in 1951 and 1952, but with relatively modest results.[139][140][141] Megestrol acetate was first studied in the treatment of breast cancer in 1967, and was one of the first progestins to be evaluated for the treatment of this disease.[4][28][142] A second study was conducted in 1974.[4][143] A "breakthrough" and surge of interest in progestins for breast cancer occurred in 1978 when a study using a massive dosage of medroxyprogesterone acetate to treat breast cancer was published.[139][144] A third study of megestrol acetate for breast cancer was published in 1980, and this was followed by additional studies in the 1980s and beyond.[4][145][146] Megestrol acetate was approved for the treatment of breast cancer in the United States by at least 1983.[4]

Progestogens, including progesterone and ethisterone, were studied in the treatment prostate cancer in 1949.[4][147] Megestrol acetate was first studied in the treatment of prostate cancer in 1970.[4][148] Additional studies were conducted in 1975 and 1978, followed by others thereafter.[4][5][48][52] However, results of megestrol acetate therapy for prostate cancer have been "disappointing",[149] and the medication has not been approved for the treatment of prostate cancer in the United States or elsewhere.[91]

Clinical studies of very high dosages of megestrol acetate for breast cancer conducted in the 1980s observed markedly increased appetite and weight gain in treated patients despite them having advanced cancer.[150][151] This led to potential interest in megestrol acetate as an appetite stimulant,[150] and in 1986, a paper was published proposing the study and potential use of megestrol acetate in cachexia.[151][152][153] Megestrol acetate was subsequently studied for this indication[154] and, following completion of phase III clinical trials, was approved as an oral suspension for the treatment of anorexia–cachexia syndrome due to cancer and other chronic conditions such as HIV/AIDS in the United States in 1993.[19][155] Thereafter, the branded product, Megace ES, has been heavily promoted by its maker, Par Pharmaceutical, for treatment of unintentional weight loss in elderly patients, especially those living in long-term care facilities. In March 2013, Par settled a $45 million federal and multi-state criminal and civil lawsuit in which the company was accused of promoting the branded version of megestrol acetate, over the generic version, for use in treating non-AIDS-related geriatric wasting. This use was not approved as safe and effective by the Food and Drug Administration (FDA), and not covered by federal health care programs. The lawsuit claimed that Par marketed the product as effective for this use, despite having conducted no well-controlled studies to support a claim of greater efficacy for Megace ES, and prior knowledge of the severe adverse side effects for geriatric patients, including deep vein thrombosis, toxic reactions with impaired renal function, and mortality.[156]

Society and culture

Generic names

Megestrol acetate is the generic name of the drug and its INNM, USAN, USP, and BANM, while megestrol is the INN and BAN and mégestrol the DCF of megestrol, the free alcohol form of megestrol acetate.[8][20][21][122] The medication is also known by its developmental code names BDH-1298, NSC-71423, and SC-10363.[8][20][21][122]

Brand names

Megestrol acetate is marketed under a variety of brand names throughout the world but is most commonly sold under the brand name Megace.[20][21][122] It is also available under the brand name Megace ES in the United States and under the brand name Megace OS in Canada.[21] For use in veterinary medicine, megestrol acetate is sold as Ovaban in the United States and as Ovarid in the United Kingdom.[21]

In Bangladesh and India, megestrol is marketed under the brand name Megestol by Ziska Pharmaceuticals, Mezest by Beacon Pharmaceuticals, and under the trade name Varigestrol by Laboratorio Varifarma, Argentina.

Availability

Megestrol acetate is available widely throughout the world, including in the United States, Canada, the United Kingdom, Ireland, elsewhere throughout Europe, Australia, New Zealand, Latin America, Asia, and a few African countries.[20][21]

Generation

Progestins in birth control pills are sometimes grouped by generation.[157][158] While the 19-nortestosterone progestins are consistently grouped into generations, the pregnane progestins that are or have been used in birth control pills are typically omitted from such classifications or are grouped simply as "miscellaneous" or "pregnanes".[157][158] In any case, based on its date of introduction in such formulations of 1963, megestrol acetate could be considered a "first-generation" progestin.[13]

Research

Megestrol acetate has been studied in men in combination with testosterone as a male hormonal contraceptive to suppress spermatogenesis.[5][159]

Veterinary use

Megestrol acetate has been used in veterinary medicine under the brand name Ovaban in the treatment of medical conditions in cats and dogs.[20][160] Due to its ability to suppress testosterone levels, megestrol acetate can control sexually dimorphic traits in males.[161][162] As a result, megestrol acetate has been used to reduce dominance, inter-male aggression, mounting, urine spraying, and roaming in male dogs and cats.[161][162]

See also

  • Estradiol/megestrol acetate
  • Ethinylestradiol/megestrol acetate

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 "Megace ES- megesterol acetate suspension". 18 March 2014. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=654854bc-f847-4e3b-a0a1-8716553460ac. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 "Pharmacology of estrogens and progestogens: influence of different routes of administration". Climacteric 8 (Suppl 1): 3–63. August 2005. doi:10.1080/13697130500148875. PMID 16112947. http://hormonebalance.org/images/documents/Kuhl%2005%20%20Pharm%20Estro%20Progest%20Climacteric_1313155660.pdf. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Principles and Practice of Gynecologic Oncology. Lippincott Williams & Wilkins. 2009. pp. 447–. ISBN 978-0-7817-7845-9. https://books.google.com/books?id=hsMne5mAXSIC&pg=PA447. 
  4. 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.21 4.22 "Megestrol acetate". Cancer Treatment Reviews 10 (3): 141–157. September 1983. doi:10.1016/0305-7372(83)90029-4. PMID 6352021. 
  5. 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 5.11 5.12 5.13 "Megestrol acetate: clinical experience". Cancer Treatment Reviews 16 (1): 49–63. March 1989. doi:10.1016/0305-7372(89)90004-2. PMID 2471590. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Sexual Chemistry: A History of the Contraceptive Pill. Yale University Press. 2010. pp. 77–78. ISBN 978-0-300-16791-7. https://books.google.com/books?id=_i-s4biQs7MC&pg=PA78. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 "A new type of oral contraceptive". British Medical Journal 1 (5341): 1318–1320. May 1963. doi:10.1136/bmj.1.5341.1318. PMID 13934321. 
  8. 8.0 8.1 8.2 Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer. 1999. p. 173. ISBN 978-0-7514-0499-9. https://books.google.com/books?id=mqaOMOtk61IC&pg=PA173. Retrieved 2 June 2012. 
  9. 9.0 9.1 Principles And Practice of Palliative Care And Supportive Oncology. Lippincott Williams & Wilkins. 6 October 2006. p. 128. ISBN 978-0-7817-9595-1. https://books.google.com/books?id=LngD6RFXY_AC&pg=PA128. Retrieved 27 May 2012. 
  10. 10.0 10.1 Management of Acute Kidney Problems. Springer. 19 February 2010. p. 210. ISBN 978-3-540-69413-7. https://books.google.com/books?id=pS3ff7txLl4C&pg=PA210. Retrieved 27 May 2012. 
  11. 11.0 11.1 Supportive Care in Cancer Therapy. Springer. 11 November 2008. p. 61. ISBN 978-1-58829-941-3. https://books.google.com/books?id=Erhb8XfG3qIC&pg=PA61. Retrieved 27 May 2012. 
  12. 12.0 12.1 Benign Prostatic Hypertrophy. Springer Science & Business Media. 6 December 2012. pp. 277–. ISBN 978-1-4612-5476-8. https://books.google.com/books?id=Z5K-BwAAQBAJ&pg=PA277. 
  13. 13.0 13.1 Obstetrics, Gynecology & Infertility: Handbook for Clinicians. Scrub Hill Press, Inc.. 2007. pp. 228–. ISBN 978-0-9645467-7-6. https://books.google.com/books?id=2JLC6yiA7fcC&pg=PA228. 
  14. 14.0 14.1 Consolidated List of Products Whose Consumption And/or Sale Have Been Banned, Withdrawn, Severely Restricted Or Not Approved by Governments. United Nations Publications. 1983. pp. 137–. ISBN 978-92-1-130230-1. https://books.google.com/books?id=leVCukUgNlsC&pg=PA137. 
  15. 15.0 15.1 "Mammary nodules in dogs during four years' treatment with megestrol acetate or chlormadinone acetate". Journal of the National Cancer Institute 51 (4): 1303–1311. October 1973. doi:10.1093/jnci/51.4.1303. PMID 4126857. 
  16. 16.0 16.1 16.2 FDA Consumer. U.S. Department of Health, Education, and Welfare, Public Health Service, Food and Drug Administration. February 1976. https://books.google.com/books?id=pLG-19fghW8C. "Several foreign countries, including Germany, Canada, and Great Britain, have banned the sale of birth control pills containing megestrol acetate after a study done at FDA's request indicated it caused breast cancer in dogs. Megestrol acetate has never been marketed in the United States as an oral contraceptive. FDA routinely requires long-term animal studies before any drug can be marketed for human use. Following animal studies with megestrol acetate, FDA in the late sixties and early seventies allowed limited studies of the drug in women. In 1972, after noticing a significant number of test dogs developing breast nodules (none of them malignant), FDA ordered that megestrol acetate be discontinued in human oral contraceptive studies." 
  17. 17.0 17.1 United States. Congress. Senate. Committee on Labor and Public Welfare (1976). Hearings, Reports and Prints of the Senate Committee on Labor and Public Welfare. U.S. Government Printing Office. https://books.google.com/books?id=Fto1AAAAIAAJ. "Megestrol was never marketed in the United States for contraceptive use because in 1972, FDA took prompt action to discontinue investigational studies on megestrol after dogs exposed to the drug for four years In a chronic toxicity study developed benign breast tumors." 
  18. 18.0 18.1 Female Contraception: Update and Trends. Springer Science & Business Media. 6 December 2012. pp. 134–. ISBN 978-3-642-73790-9. https://books.google.com/books?id=LtT6CAAAQBAJ&pg=PA134. 
  19. 19.0 19.1 Risk Factors for Pancreatic Cancer: Underlying Mechanisms and Potential Targets. Frontiers Media SA. 22 April 2015. pp. 96–. ISBN 978-2-88919-468-1. https://books.google.com/books?id=G0gsCQAAQBAJ&pg=PA96. 
  20. 20.0 20.1 20.2 20.3 20.4 20.5 20.6 20.7 20.8 20.9 Index Nominum 2000: International Drug Directory. Taylor & Francis US. 2000. p. 641. ISBN 978-3-88763-075-1. https://books.google.com/books?id=5GpcTQD_L2oC&pg=PA641. Retrieved 2 June 2012. 
  21. 21.0 21.1 21.2 21.3 21.4 21.5 21.6 "Megestrol". https://www.drugs.com/international/megestrol.html. 
  22. "Generic Megace Availability". https://www.drugs.com/availability/generic-megace.html. 
  23. 23.0 23.1 23.2 23.3 23.4 23.5 23.6 23.7 23.8 Principles and Practice of Endocrinology and Metabolism. Lippincott Williams & Wilkins. 24 April 2001. pp. 1195–1196. ISBN 978-0-7817-1750-2. https://books.google.com/books?id=FVfzRvaucq8C&pg=PA1195. Retrieved 27 May 2012. 
  24. 24.0 24.1 "Progesterone therapy for the treatment of non-cancer cachexia: a systematic review". BMJ Supportive & Palliative Care 6 (3): 276–286. September 2016. doi:10.1136/bmjspcare-2015-001041. PMID 27098973. 
  25. 25.0 25.1 "Megestrol acetate for treatment of anorexia-cachexia syndrome". The Cochrane Database of Systematic Reviews 2013 (3): CD004310. March 2013. doi:10.1002/14651858.CD004310.pub3. PMID 23543530. 
  26. "Antiemetic properties of megestrol acetate". Journal of Palliative Medicine 9 (2): 239–240. April 2006. doi:10.1089/jpm.2006.9.239. PMID 16629544. 
  27. "Antiemetic activity of megestrol acetate in patients receiving chemotherapy". Supportive Care in Cancer 19 (5): 667–673. May 2011. doi:10.1007/s00520-010-0886-x. PMID 20419494. 
  28. 28.0 28.1 "An overview of megestrol acetate for the treatment of advanced breast cancer". Seminars in Oncology 15 (2 Suppl 1): 3–13. April 1988. PMID 3285483. 
  29. Handbook of Metastatic Breast Cancer, Second Edition. CRC Press. 14 November 2011. pp. 18–. ISBN 978-1-84184-812-9. https://books.google.com/books?id=eYTOBQAAQBAJ&pg=PA18. 
  30. 30.0 30.1 30.2 30.3 Sexual Chemistry: A History of the Contraceptive Pill. Yale University Press. 2001. pp. 78–. ISBN 978-0-300-08943-1. https://books.google.com/books?id=GgvLA3bqwnoC&pg=PA78. 
  31. 31.0 31.1 31.2 "A review of "once-a-month" combined injectable contraceptives". Journal of Obstetrics and Gynaecology 4 (Suppl 1): S1-34. 1994. doi:10.3109/01443619409027641. PMID 12290848. 
  32. "Comparison of megestrol acetate and clomiphene citrate as supplemental medication in postmenopausal oestrogen replacement therapy". Archives of Gynecology 234 (1): 49–58. 1983. doi:10.1007/bf02114725. PMID 6660928. 
  33. "Effect of megestrol acetate on flushing and bone metabolism in post-menopausal women". Maturitas 3 (2): 167–172. August 1981. doi:10.1016/0378-5122(81)90008-6. PMID 7289887. 
  34. "The role of megestrol acetate as an alternative to conventional hormone replacement therapy". Climacteric 3 (2): 125–134. June 2000. doi:10.3109/13697130009167614. PMID 11910653. 
  35. "Megestrol acetate for the prevention of hot flashes". The New England Journal of Medicine 331 (6): 347–352. August 1994. doi:10.1056/NEJM199408113310602. PMID 8028614. 
  36. "Estrogenic side effects of androgen deprivation therapy". Reviews in Urology 9 (4): 163–180. 2007. PMID 18231613. 
  37. "Managing hot flushes in men after prostate cancer--a systematic review". Maturitas 65 (1): 15–22. January 2010. doi:10.1016/j.maturitas.2009.10.017. PMID 19962840. 
  38. "Intramuscular depot medroxyprogesterone versus oral megestrol for the control of postmenopausal hot flashes in breast cancer patients: a randomized study". Annals of Oncology 13 (6): 883–888. June 2002. doi:10.1093/annonc/mdf151. PMID 12123333. 
  39. 39.0 39.1 39.2 "The oral progestational and anti-ovulatory properties of megestrol acetate and its therapeutic use in gynaecological disorders". The Journal of Obstetrics and Gynaecology of the British Empire 72 (1): 45–48. February 1965. doi:10.1111/j.1471-0528.1965.tb01372.x. PMID 12332461. 
  40. "Clinical results of treatment with megestrol acetate in menstrual disorders and contraception". The Indian Practitioner 19 (8): 597–600. August 1966. PMID 5916119. 
  41. "Megestrol acetate for treatment of endometriosis". Obstetrics and Gynecology 75 (4): 646–648. April 1990. PMID 2314784. 
  42. "Long-term effect of megestrol acetate in the treatment of endometrial hyperplasia". American Journal of Obstetrics and Gynecology 146 (3): 316–322. June 1983. doi:10.1016/0002-9378(83)90754-8. PMID 6859142. 
  43. "Megestrol acetate for the palliation of advanced ovarian carcinoma". Obstetrics and Gynecology 61 (1): 95–98. January 1983. PMID 6185891. 
  44. "The use of high-dose megestrol acetate in the treatment of ovarian adenocarcinoma". Seminars in Oncology 12 (1 Suppl 1): 20–22. March 1985. PMID 3975647. 
  45. "High-dose megestrol acetate therapy of ovarian carcinoma: a phase II study by the Northern California Oncology Group". Seminars in Oncology 13 (4 Suppl 4): 26–32. December 1986. PMID 3099393. 
  46. "Phase II study of high-dose megestrol acetate in patients with advanced ovarian carcinoma". European Journal of Cancer 30A (5): 697–698. 1994. doi:10.1016/0959-8049(94)90548-7. PMID 8080689. 
  47. "[Hormone therapy of prostatic neoplasms]" (in de). Der Urologe 10 (3): 117–119. May 1971. PMID 4104209. 
  48. 48.0 48.1 "Treatment of advanced cancer of prostate with megestrol acetate". Urology 12 (5): 537–541. November 1978. doi:10.1016/0090-4295(78)90467-3. PMID 153029. 
  49. "Treatment of stage D prostatic carcinoma with megestrol acetate". Journal of Surgical Oncology 17 (4): 367–371. 1981. doi:10.1002/jso.2930170409. PMID 7265976. 
  50. 50.0 50.1 50.2 50.3 "Medical castration of males with megestrol acetate and small doses of diethylstilbestrol". The Journal of Clinical Endocrinology and Metabolism 52 (3): 576–580. March 1981. doi:10.1210/jcem-52-3-576. PMID 6161942. 
  51. 51.0 51.1 "Medical castration with megestrol acetate and minidose of diethylstilbestrol". Urology 17 (4 Suppl): 27–33. April 1981. PMID 6782738. 
  52. 52.0 52.1 "Megestrol acetate for treatment of advanced carcinoma of the prostate". Journal of Surgical Oncology 7 (1): 9–15. 1975. doi:10.1002/jso.2930070103. PMID 1177459. 
  53. "Megestrol acetate used as primary hormonal therapy in stage D prostatic cancer". Seminars in Oncology 12 (1 Suppl 1): 36–39. March 1985. PMID 3975650. 
  54. "A study of endocrine function in the treatment of benign prostatic hypertrophy with megestrol acetate". Acta Obstetricia et Gynecologica Scandinavica 46 (S9): 25–38. 1967. doi:10.3109/00016346709156833. PMID 4169449. 
  55. "Megestrol acetate in treatment of benign prostatic hypertrophy". Urology 6 (5): 580–587. November 1975. doi:10.1016/0090-4295(75)90506-3. PMID 52933. 
  56. "Response to megestrol in male breast carcinoma". Archives of Internal Medicine 141 (6): 809–810. May 1981. doi:10.1001/archinte.1981.00340060117031. PMID 6263202. 
  57. "[Clinical study on treatment of female idiopathic precocious puberty with combined therapy of Chinese medicine and megestrol acetate]" (in zh). Zhongguo Zhong Xi Yi Jie He Za Zhi Zhongguo Zhongxiyi Jiehe Zazhi = Chinese Journal of Integrated Traditional and Western Medicine 21 (10): 732–735. October 2001. PMID 12575602. 
  58. "Androgenetic alopecia and its treatment. A historical overview". Hair Transplantation (Third ed.). Taylor & Francis. 1 February 1995. pp. 1–33. ISBN 978-0-8247-9363-0. https://books.google.com/books?id=_KxsAAAAMAAJ. 
  59. 59.0 59.1 Davis's Pocket Clinical Drug Reference. F.A. Davis. 16 March 2009. pp. 167–. ISBN 978-0-8036-2305-7. https://books.google.com/books?id=1WH2AAAAQBAJ&pg=PA167. 
  60. "Phase III evaluation of 4 doses of megestrol acetate as therapy for patients with cancer anorexia and/or cachexia". Oncology 51 (Suppl 1): 2–7. October 1994. doi:10.1159/000227407. PMID 7970505. 
  61. The APRN's Complete Guide to Prescribing Pediatric Drug Therapy 2. Springer Publishing Company. 26 July 2017. pp. 18–. ISBN 978-0-8261-6669-2. https://books.google.com/books?id=98ypDgAAQBAJ&pg=PA18. 
  62. "A randomized comparison of megestrol acetate (MA) and medroxyprogesterone acetate (MPA) in patients with advanced breast cancer". European Journal of Cancer 26 (3): 337–343. March 1990. doi:10.1016/0277-5379(90)90231-h. PMID 2141491. 
  63. Male Hypogonadism: Basic, Clinical and Therapeutic Principles. Humana Press. 25 April 2017. pp. 407–. ISBN 978-3-319-53298-1. https://books.google.com/books?id=UFi-DgAAQBAJ&pg=PA407. 
  64. 64.0 64.1 "Update on clinical trials of growth factors and anabolic steroids in cachexia and wasting". The American Journal of Clinical Nutrition 91 (4): 1143S–1147S. April 2010. doi:10.3945/ajcn.2010.28608E. PMID 20164318. 
  65. "Osteoporosis associated with megestrol acetate". Mayo Clinic Proceedings 79 (12): 1557–1561. December 2004. doi:10.4065/79.12.1557. PMID 15595341. 
  66. "Treatment with nandrolone decanoate and megestrol acetate in HIV-infected men". Nutrition in Clinical Practice 20 (1): 93–97. February 2005. doi:10.1177/011542650502000193. PMID 16207650. 
  67. "Testosterone supplementation of megestrol therapy does not enhance lean tissue accrual in men with human immunodeficiency virus-associated weight loss: a randomized, double-blind, placebo-controlled, multicenter trial". The Journal of Clinical Endocrinology and Metabolism 92 (2): 563–570. February 2007. doi:10.1210/jc.2006-0954. PMID 17090640. 
  68. "Effect of Megestrol Acetate and Testosterone on Body Composition and Hormonal Responses in COPD Cachexia". Chronic Obstructive Pulmonary Diseases 3 (1): 389–397. November 2015. doi:10.15326/jcopdf.3.1.2015.0128. PMID 28848861. 
  69. 69.0 69.1 "Glucocorticoidlike activity of megestrol. A summary of Food and Drug Administration experience and a review of the literature". Archives of Internal Medicine 157 (15): 1651–1656. 1997. doi:10.1001/archinte.1997.00440360053005. PMID 9250225. 
  70. "High prevalence of adrenal suppression during acute illness in hospitalized patients receiving megestrol acetate". Journal of Endocrinological Investigation 29 (2): 136–140. February 2006. doi:10.1007/bf03344086. PMID 16610239. 
  71. "Megestrol acetate-associated adrenal insufficiency". The American Journal of Geriatric Pharmacotherapy 6 (3): 167–172. August 2008. doi:10.1016/j.amjopharm.2008.08.004. PMID 18775392. 
  72. "Megestrol acetate therapy in geriatric patients: case reviews and associated deep vein thrombosis". The Consultant Pharmacist 18 (9): 764–773. September 2003. PMID 16563066. 
  73. "Jaundice and intrahepatic cholestasis following high-dose megestrol acetate for breast cancer". Cancer 63 (3): 438–439. February 1989. doi:10.1002/1097-0142(19890201)63:3<438::aid-cncr2820630307>3.0.co;2-o. PMID 2912522. 
  74. "Multiple meningiomas arising during long-term therapy with the progesterone agonist megestrol acetate. Case report". Journal of Neurosurgery 100 (2): 328–331. February 2004. doi:10.3171/jns.2004.100.2.0328. PMID 15086241. 
  75. "Intracranial meningiomas in patients with uterine sarcoma treated with long-term megestrol acetate therapy". World Neurosurgery 76 (5): 477.e16–477.e20. November 2011. doi:10.1016/j.wneu.2011.03.035. PMID 22152580. 
  76. 76.0 76.1 "Choosing Wisely". https://www.aafp.org/afp/recommendations/viewRecommendation.htm?recommendationId=183. 
  77. 77.0 77.1 "Overview of hormonal therapy in advanced breast cancer". Seminars in Oncology 17 (6 Suppl 9): 38–46. December 1990. PMID 2148026. http://www.seminoncol.org/article/0093-7754(90)90007-P/abstract. Retrieved 24 March 2018. "Doses [of megestrol acetate] of as high as 1,600 mg/d, given in divided doses three or four times daily, have been given with no clear increase in side effects except for weight gain, mild increases in blood pressure (BP), and some fluid retention.45". 
  78. 78.0 78.1 78.2 78.3 78.4 78.5 78.6 78.7 78.8 Cite error: Invalid <ref> tag; no text was provided for refs named pmid14670641
  79. 79.0 79.1 79.2 79.3 79.4 79.5 79.6 79.7 79.8 79.9 "Pharmacology of Progestogens". Progestogens in Obstetrics and Gynecology. Springer. 2015. pp. 33–40. doi:10.1007/978-3-319-14385-9_2. ISBN 978-3-319-14384-2. 
  80. 80.0 80.1 "Classification and pharmacology of progestins". Maturitas 61 (1–2): 171–180. 2008. doi:10.1016/j.maturitas.2008.11.013. PMID 19434889. 
  81. 81.0 81.1 81.2 81.3 81.4 81.5 81.6 "Pharmacology of progestogens". Journal für Reproduktionsmedizin und Endokrinologie-Journal of Reproductive Medicine and Endocrinology 8 (Special Issue 1): 157–176. 2011. http://www.kup.at/kup/pdf/10168.pdf. 
  82. 82.0 82.1 "Therapeutic options in treatment of advanced carcinoma of the prostate". Seminars in Oncology 17 (6 Suppl 9): 73–77. December 1990. PMID 2259929. 
  83. 83.0 83.1 "Influence of progestins on serum hormone levels in postmenopausal women with advanced breast cancer--I. General findings". Journal of Steroid Biochemistry 36 (1–2): 99–104. June 1990. doi:10.1016/0022-4731(90)90118-c. PMID 2362454. 
  84. 84.0 84.1 84.2 "Acute therapy with megestrol acetate decreases nuclear and cytosol androgen receptors in human BPH tissue". The Prostate 3 (1): 11–15. 1982. doi:10.1002/pros.2990030103. PMID 6176985. 
  85. 85.0 85.1 "The role of progestins in the treatment of breast cancer". Seminars in Oncology 10 (4 Suppl 4): 7–10. December 1983. PMID 6230722. 
  86. "Endocrine effects of the combination of megestrol acetate and tamoxifen in the treatment of metastatic breast cancer". European Journal of Cancer & Clinical Oncology 20 (9): 135–140. September 1984. doi:10.1016/0277-5379(84)90121-4. PMID 6434315. 
  87. "Ovulation inhibition doses of progestins: a systematic review of the available literature and of marketed preparations worldwide". Contraception 84 (6): 549–557. December 2011. doi:10.1016/j.contraception.2011.04.009. PMID 22078182. 
  88. "Randomised double-blind trial of four oral progestagen-only contraceptives". The Lancet 299 (7757): 915–922. 1972. doi:10.1016/S0140-6736(72)91492-4. ISSN 0140-6736. 
  89. The Control of Fertility. Elsevier. 3 September 2013. pp. 222–. ISBN 978-1-4832-7088-3. https://books.google.com/books?id=ehQlBQAAQBAJ&pg=PA222. 
  90. The Medical Management of Prostate Cancer. Springer Science & Business Media. 6 December 2012. pp. 45–. ISBN 978-3-642-73238-6. https://books.google.com/books?id=T78hBQAAQBAJ&pg=PT45. 
  91. 91.0 91.1 91.2 91.3 Prostate Cancer and Bone Metastasis. Springer Science & Business Media. 6 December 2012. pp. 309–. ISBN 978-1-4615-3398-6. https://books.google.com/books?id=rgnrBwAAQBAJ&pg=PA309. 
  92. Biological and Hormonal Therapies of Cancer. Springer Science & Business Media. 6 December 2012. pp. 73–. ISBN 978-1-4615-6189-7. https://books.google.com/books?id=So3IAwAAQBAJ&pg=PA73. 
  93. "New methods of endocrine management of prostatic cancer". The Journal of Urology 137 (1): 1–10. January 1987. doi:10.1016/s0022-5347(17)43855-9. PMID 3540320. 
  94. "Megestrol acetate plus minidose diethylstilbestrol in the treatment of carcinoma of the prostate". Seminars in Oncology 15 (2 Suppl 1): 62–67. April 1988. PMID 3285485. 
  95. "Medical castration using megestrol acetate and minidose estrogen". Urology 31 (5): 371–374. May 1988. doi:10.1016/0090-4295(88)90726-1. PMID 3284149. 
  96. "Megestrol acetate and minidose estrogen in prostatic carcinoma". Urology 32 (3): 281–283. September 1988. doi:10.1016/0090-4295(88)90402-5. PMID 3413920. 
  97. "Megestrol acetate plus low-dose estrogen in the management of advanced prostatic carcinoma". The Urologic Clinics of North America 18 (1): 83–91. February 1991. doi:10.1016/S0094-0143(21)01395-1. PMID 1825145. 
  98. "Profound suppression of plasma estrogens by megestrol acetate in postmenopausal breast cancer patients". Clinical Cancer Research 2 (9): 1515–1521. September 1996. PMID 9816328. 
  99. "Changes in serum sex steroid levels during megestrol acetate therapy". Surgical Oncology 3 (6): 351–359. December 1994. doi:10.1016/0960-7404(94)90074-4. PMID 7773452. 
  100. "Additive endocrine therapy for advanced breast cancer - back to the future". Acta Oncologica 48 (8): 1092–1101. 2009. doi:10.3109/02841860903117816. PMID 19863216. 
  101. "The use of human skin fibroblasts to obtain potency estimates of drug binding to androgen receptors". The Journal of Clinical Endocrinology and Metabolism 59 (1): 51–55. July 1984. doi:10.1210/jcem-59-1-51. PMID 6725525. 
  102. 102.0 102.1 "Androgenic activity of synthetic progestins and spironolactone in androgen-sensitive mouse mammary carcinoma (Shionogi) cells in culture". Journal of Steroid Biochemistry 31 (5): 845–852. November 1988. doi:10.1016/0022-4731(88)90295-6. PMID 2462135. 
  103. 103.0 103.1 "Comparison of the antiandrogenic/androgenic activities of flutamide, cyproterone acetate and megestrol acetate". Molecular and Cellular Endocrinology 42 (3): 283–288. October 1985. doi:10.1016/0303-7207(85)90059-0. PMID 3930312. 
  104. 104.0 104.1 "Megestrol acetate: promises and pitfalls". AIDS Patient Care and STDs 13 (3): 149–152. March 1999. doi:10.1089/apc.1999.13.149. PMID 10375262. 
  105. "Androgenic properties and adrenal depressant activity of megestrol acetate observed in castrated male rats". Acta Endocrinologica 78 (2): 316–324. February 1975. doi:10.1530/acta.0.0780316. PMID 1172901. 
  106. 106.0 106.1 "Sex hormone binding globulin capacity as an index of oestrogenicity or androgenicity in women on oral contraceptive steroids". Clinical Endocrinology 10 (1): 39–45. January 1979. doi:10.1111/j.1365-2265.1979.tb03031.x. PMID 571314. 
  107. Genitourinary Cancer: Basic and Clinical Aspects. Springer Science & Business Media. 6 December 2012. pp. 171–. ISBN 978-1-4613-2033-3. https://books.google.com/books?id=QUp-BgAAQBAJ&pg=PA171. 
  108. "Analysis of the androgenic activity of synthetic "progestins" currently used for the treatment of prostate cancer". Journal of Steroid Biochemistry 28 (4): 379–384. October 1987. doi:10.1016/0022-4731(87)91054-5. PMID 2444770. 
  109. "Glucocorticoid properties of progestogens". Steroids 22 (4): 555–559. October 1973. doi:10.1016/0039-128x(73)90011-1. PMID 4747450. 
  110. "Effects of Progesterone and Related Steroids in the Brain". Progestins and Antiprogestins in Clinical Practice. Taylor & Francis. 10 November 1999. pp. 15–58. ISBN 978-0-8247-8291-7. https://books.google.com/books?id=vGJJHsJASekC. "Specific actions of neurosteroids on ion transport across the neuronal plasma membrane have been described (see Fig. 2[10). In hippocampal CA1 neurons, Ffrench Mullen et al. (76) observed an inhibition by PREG, PREGS, and 3α,5β-TH PROG (but not PROG) of both the N- and L-type calcium channel currents, mediated by a pertussis toxin-sensitive G protein mechanism, associated with the activation of protein kinase C. PROG still has no effect on calcium channels of hypothalamic neurons from the ventromedial nucleus; however, the synthetic progestin megestrol acetate inhibits some high-threshold Ca2+ channel currents: not the N-type nor the P-type Ca2+ channel currents, but the residual current. Appetite enhancement induced by megestrol acetate might be partly due to the inhibition of these Ca2+ channel currents, and the attenuation of the firing of ventromedial nucleus neurons, involved in satiety mechanisms (77)." 
  111. 111.0 111.1 111.2 111.3 111.4 "Effects of treatment with megestrol acetate on the insulin-like growth factor system: time and dose dependency". European Journal of Cancer 35 (7): 1070–1075. July 1999. doi:10.1016/s0959-8049(99)00055-6. PMID 10533450. 
  112. Biological and Hormonal Therapies of Cancer. Springer. 1998. p. 73. ISBN 978-0-7923-9997-1. https://books.google.com/books?id=8KnTy0eCQ9AC&pg=PA73. Retrieved 2 June 2012. 
  113. 113.0 113.1 "Pharmacokinetics and potency of progestins used for hormone replacement therapy and contraception". Reviews in Endocrine & Metabolic Disorders 3 (3): 211–224. September 2002. doi:10.1023/A:1020072325818. PMID 12215716. 
  114. 114.0 114.1 "Progesterone: review of safety for clinical studies". Experimental and Clinical Psychopharmacology 15 (5): 427–444. October 2007. doi:10.1037/1064-1297.15.5.427. PMID 17924777. 
  115. 115.0 115.1 "Improved bioavailability of a micronized megestrol acetate tablet formulation in humans". Drug Development and Industrial Pharmacy 26 (5): 567–570. May 2000. doi:10.1081/ddc-100101270. PMID 10789071. 
  116. "Pharmacokinetics of megestrol acetate in women receiving IM injection of estradiol-megestrol long-acting injectable contraceptive". The Chinese Journal of Clinical Pharmacology. April 1986. http://en.cnki.com.cn/Article_en/CJFDTOTAL-GLYZ198604003.htm. Retrieved 14 August 2019. "A radioimmunoassay (RIA), radioligand assay and equilibrium dialysis for determination of plasma and salivary megestrol acetate (MA) concentration, sex hormone binding globulin (SHBG) capacity in plasma and percentage albumin bound MA were studied in healthy women receiving single im injection of estradiol-megestrol long-acting injectable contraceptive. The results showed that after injection the concentration of plasma MA increased rapidly. The meantime of peak plasma MA level was 3rd day, there was a linear relationship between log of plasma MA concentration and time (day) after administration in all subjects, elimination phase half-life t1/2β = 14.35 ± 9.1 days. The plasma sex hormone-binding globulin capacity significantly increased at 7th, 14th day and decreased at 21st, 29th day after injection. The percentage albumin bound MA was 82.4%. There was no specific sex hormone-binding globulin bound MA. There was a positive correlation between the MA concentrations in saliva and those in plasma.". 
  117. 117.0 117.1 117.2 Birth Control; Contraception and Abortion. Macmillan. 1973. ISBN 9780024044105. https://books.google.com/books?id=B6hsAAAAMAAJ. 
  118. 118.0 118.1 118.2 "Endocrine therapy for gynecological cancer". Gynecological Endocrinology 13 (6): 441–456. December 1999. doi:10.3109/09513599909167590. PMID 10685337. 
  119. Biochemical Actions of Hormones. Elsevier. 2 December 2012. pp. 330–. ISBN 978-0-323-15344-7. https://books.google.com/books?id=tX9GwWPsMbQC&pg=PA330. 
  120. Foye's Principles of Medicinal Chemistry. Lippincott Williams & Wilkins. 2002. pp. 699–. ISBN 978-0-683-30737-5. https://books.google.com/books?id=qLJ6Bs1Qml4C&pg=PA699. 
  121. Die Gestagene. Springer-Verlag. 27 November 2013. p. 281. ISBN 978-3-642-99941-3. https://books.google.com/books?id=t8GpBgAAQBAJ&pg=PA281. 
  122. 122.0 122.1 122.2 122.3 122.4 122.5 122.6 The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. 14 November 2014. pp. 657–. ISBN 978-1-4757-2085-3. https://books.google.com/books?id=0vXTBwAAQBAJ&pg=PA657. 
  123. Endocrine Therapies in Breast Cancer. OUP Oxford. 8 November 2007. pp. 75–. ISBN 978-0-19-921814-1. https://books.google.com/books?id=4aAH2Ik-9KcC&pg=PT75. 
  124. "[Effect of progestin no. 1 (cymegesolate) on menstrual cycles and plasma levels of progesterone in rhesus monkeys]" (in zh). Sheng Li Xue Bao 37 (4): 368–373. August 1985. PMID 3837333. 
  125. "[Clinical study of a long-acting progestogen contraceptive 3-cyclopentyl propionate of megestrol acetate (progestin no. 1)]" (in zh). Sheng Zhi Yu Bi Yun = Reproduction and Contraception 3 (2): 36–38. February 1983. PMID 12339176. 
  126. "Effect of megestrol caproate on the reproductive function of laboratory animals". Bulletin of Experimental Biology and Medicine 133 (6): 574–576. June 2002. doi:10.1023/A:1020233925626. PMID 12447469. 
  127. "Steroids. CXVIII.16-Methyl Derivatives of 17α-Hydroxyprogesterone and of Reichstein's Substance "S"". Journal of the American Chemical Society 81 (14): 3712–3716. 1959. doi:10.1021/ja01523a055. ISSN 0002-7863. 
  128. "Synthesis of [1,2-3H2]medroxyprogesterone acetate (17-alpha-acetoxy-6-alpha-methyl[1,2-3H2]pregn-4-ene-3,20-dione) and [1,2-3H2]megestrol acetate (17-alpha-acetoxy-6-methyl[1,2-3H2]pregna-4,6-diene-3,20-dione)". The Biochemical Journal 93 (1): 8C–9C. October 1964. doi:10.1042/bj0930008c. PMID 5320316. 
  129. Oral Contraceptives: Psychological and Physiological Effects. Ardent Media. 1973. pp. 12–. ISBN 978-0-8422-7101-1. https://books.google.com/books?id=lhL3R4WTPEEC&pg=PA12. 
  130. Statens seruminstitut (Denmark) (1966). Communications: Extraits. https://books.google.com/books?id=xyLQAAAAMAAJ. "Each Delpregnin tablet contains 5 mg megestrol acetate + 0.1 mg mestranol." 
  131. Unlisted Drugs. Pharmaceutical Section, Special Libraries Association.. 1965. https://books.google.com/books?id=wxNtAAAAMAAJ. 
  132. 132.0 132.1 "Drug discontinuations in the United Kingdom and the United States, 1964 to 1983: issues of safety". Clinical Pharmacology and Therapeutics 35 (5): 559–567. May 1984. doi:10.1038/clpt.1984.78. PMID 6713769. 
  133. Modern Veterinary Practice. 1971. https://books.google.com/books?id=2K0iAQAAIAAJ. "Your Q & A concerning megestrol acetate (Oct MVP, p 27), a product containing this compound (Ovarid: Glaxo) has been commercially available for controlling estrus in bitches in the UK for nearly 2 years." 
  134. VM/SAC, Veterinary Medicine/small Animal Clinician. Veterinary Medicine Publishing Company. 1977. https://books.google.com/books?id=lBIjAQAAIAAJ. "In England, where megestrol acetate has been marketed for eight years, it is recommended to treat false pregnancy and estrogen-dependent mammary tumors in dogs. It has also been used successfully to treat hypersexuality in male dogs, and miliary dermatitis and eosinophilic granulomas in cats. In 1974, megestrol acetate was approved in the United States for postponement of es- trus and treatment of false pregnancy in dogs." 
  135. Upjohn Company (1978). Proceedings of the Symposium on Cheque® for Canine Estrus Prevention, Brook Lodge, Augusta, Michigan, March 13-15, 1978. Upjohn Company. https://books.google.com/books?id=wPFUAAAAYAAJ. "In 1974, Sobering marketed megestrol acetate3 (Figure 1) under the trade name of Ovaban® (Ovarid® in Europe)." 
  136. "Histological effects of progestins on hyperplasia and carcinoma in situ of the endometrium". Cancer 12 (6): 1106–1122. 1959. doi:10.1002/1097-0142(195911/12)12:6<1106::aid-cncr2820120607>3.0.co;2-m. PMID 14409476. 
  137. "The use of megestrol acetate in the treatment of advanced malignant lesions of the endometrium". Gynecologic Oncology 1 (4): 340–344. 1973. doi:10.1016/0090-8258(73)90026-7. ISSN 0090-8258. 
  138. "Megestrol acetate in the management of advanced endometrial carcinoma". Obstetrics and Gynecology 41 (1): 129–136. January 1973. PMID 4682608. 
  139. 139.0 139.1 "Progestins in breast cancer treatment. A review". Acta Oncologica 31 (7): 709–722. 1992. doi:10.3109/02841869209083859. PMID 1476750. 
  140. "Hormones in breast metastasis therapy". The Medical Clinics of North America 35 (1): 51–61. January 1951. doi:10.1016/s0025-7125(16)35321-4. PMID 14796108. 
  141. "Hormonal therapy in cancer of the breast. III. Effect of progesterone on clinical course and hormonal excretion". Cancer 5 (2): 275–277. March 1952. doi:10.1002/1097-0142(195203)5:2<275::aid-cncr2820050213>3.0.co;2-h. PMID 14905411. 
  142. "Progestin therapy of breast cancer: comparison of agents". British Medical Journal 3 (5561): 338–341. August 1967. doi:10.1136/bmj.3.5561.338. PMID 6029163. 
  143. "A clinical trial of megestrol acetate in advanced breast cancer". Cancer 33 (4): 907–910. April 1974. doi:10.1002/1097-0142(197404)33:4<907::aid-cncr2820330403>3.0.co;2-y. PMID 4819220. 
  144. "A possible new approach to the treatment of metastatic breast cancer: massive doses of medroxyprogesterone acetate". Cancer Treatment Reports 62 (4): 499–504. April 1978. PMID 350387. 
  145. "Progestin therapy in advanced breast cancer: megestrol acetate--an evaluation of 160 treated cases". Cancer 46 (11): 2369–2372. December 1980. doi:10.1002/1097-0142(19801201)46:11<2369::aid-cncr2820461111>3.0.co;2-3. PMID 7438013. 
  146. "Activity of megestrol acetate in postmenopausal women with advanced breast cancer after nonsteroidal aromatase inhibitor failure: a phase II trial". Annals of Oncology 25 (4): 831–836. April 2014. doi:10.1093/annonc/mdu015. PMID 24615412. 
  147. "New horizons in the surgical management of carcinoma of the prostate gland". American Journal of Surgery 78 (2): 147–169. August 1949. doi:10.1016/0002-9610(49)90323-2. PMID 18135629. 
  148. Maltry, E. (1970). Use of megestrol acetate (a new progestational agent) in the treatment of carcinoma of the prostate. In Proceedings of the Kimbrough Urological Seminar, 18th Annual Meeting (pp. 135-137).
  149. Comprehensive Textbook of Genitourinary Oncology. Lippincott Williams & Wilkins. 2006. pp. 317–. ISBN 978-0-7817-4984-8. https://books.google.com/books?id=WIsiGZnZ_mgC&pg=PA317. 
  150. 150.0 150.1 20 Common Problems: End-of-Life Care. McGraw Hill Professional. 2002. ISBN 978-0-07-034883-7. https://books.google.com/books?id=ZPgawhewn2gC. 
  151. 151.0 151.1 "Appetite stimulation with megestrol acetate in cachectic cancer patients". Seminars in Oncology 13 (4 Suppl 4): 37–43. December 1986. PMID 3798127. 
  152. "High-dose megestrol acetate. A possible treatment for cachexia". JAMA 257 (9): 1195–1198. March 1987. doi:10.1001/jama.1987.03390090067026. PMID 3806918. 
  153. "Studies of high-dose megestrol acetate: potential applications in cachexia". Seminars in Oncology 15 (2 Suppl 1): 68–75. April 1988. PMID 3285486. 
  154. "Appetite stimulation and weight gain with megestrol acetate". Seminars in Oncology 17 (6 Suppl 9): 2–7. December 1990. PMID 2259925. 
  155. "Megestrol acetate oral suspension". The Journal of the Association of Nurses in AIDS Care 5 (4): 35–6, 44. 1994. PMID 7948971. 
  156. "Par Pharmaceutical Companies Inc. Pleads Guilty, Admits Misbranding Of Megace ES" (in en). 18 March 2015. https://www.justice.gov/usao-nj/pr/par-pharmaceutical-companies-inc-pleads-guilty-admits-misbranding-megacer-es. 
  157. 157.0 157.1 Contraceptive Choices and Realities: Proceedings of the 5th Congress of the European Society of Contraception. CRC Press. 15 February 2000. pp. 73–. ISBN 978-1-85070-067-8. https://books.google.com/books?id=-FliV0TxtEEC&pg=PA73. 
  158. 158.0 158.1 IARC Working Group on the Evaluation of Carcinogenic Risks to Humans; World Health Organization; International Agency for Research on Cancer (2007). Combined Estrogen-progestogen Contraceptives and Combined Estrogen-progestogen Menopausal Therapy. World Health Organization. pp. 44. ISBN 978-92-832-1291-1. https://books.google.com/books?id=aGDU5xibtNgC&pg=PA434. 
  159. "Control of spermatogenesis in men by combined administration of progestin and androgen". Contraception 8 (3): 191–206. 1973. doi:10.1016/0010-7824(73)90030-9. ISSN 0010-7824. 
  160. "Use of megestrol acetate in cats". Journal of the American Veterinary Medical Association 194 (5): 700–702. March 1989. PMID 2647696. 
  161. 161.0 161.1 Canine Behavior: Insights and Answers. Elsevier Health Sciences. 1 January 2009. pp. 128–. ISBN 978-1-4160-5419-1. https://books.google.com/books?id=S6o5ypyRPQEC&pg=PA128. 
  162. 162.0 162.1 "Pharmacologic management in veterinary behavioral medicine". The Veterinary Clinics of North America. Small Animal Practice 33 (2): 365–404, vii. March 2003. doi:10.1016/S0195-5616(02)00130-4. PMID 12701517. 

Further reading