Chemistry:Tiagabine

From HandWiki

Tiagabine, sold under the brand name Gabitril, is an anticonvulsant medication which is used in the treatment of epilepsy.[1][2][3][4] It is also used off-label in the treatment of insomnia[5][6][7] and anxiety disorders.[8] However, off-label use is discouraged as the drug has been associated with new-onset seizures in people without epilepsy.[9][10][1] Tiagabine is taken orally.[3][2]

Side effects of tiagabine include dizziness, asthenia, non-specific nervousness, muscle tremors, diarrhea, depression, and emotional lability.[3][1] The drug acts as a selective GABA transporter 1 (GAT-1) blocker or GABA reuptake inhibitor, and hence acts as an indirect GABA receptor agonist, increasing GABAergic signaling in the brain.[3][11][12][13][14][15] It may increase activation of both GABAA and GABAB receptors.[13][16][17] The effects of tiagabine on sleep resemble those of GABAA receptor agonists like gaboxadol and muscimol, primarily enhancing slow wave sleep, and differ from those of GABAA receptor positive allosteric modulators like benzodiazepines and Z drugs.[18][15][5][19][13] The drug's elimination half-life is 4.5 to 9 hours, but can be shorter in people taking enzyme-inducing anticonvulsants.[3][14][1][2]

Tiagabine was discovered in 1988[20] and was introduced for medical use in 1997.[21][4] Generic formulations have become available.[22] The drug is not a controlled substance in the United States.[23]

Medical uses

Epilepsy

Tiagabine is approved by the United States Food and Drug Administration (FDA) as an adjunctive treatment for partial seizures in epilepsy in individuals of age 12 and up. It is effective as monotherapy and combination therapy with other anticonvulsant drugs in the treatment of partial seizure.[24]

Other uses

Insomnia

Tiagabine is used in the treatment of insomnia.[5][25][6][7] Lower doses than those used in epilepsy, in the range of 2 to 16 mg, are used to treat insomnia.[26][27]

The drug has been found to enhance slow wave sleep (SWS) in the context of insomnia.[5][25][28][29][30][31] Its effects on SWS are dose dependent, with a 2- to 4-fold increase in SWS at doses of 8 to 16 mg but mixed findings for a dose of 4 mg.[5][29][31][28][30] Findings are mixed in terms of the influence of tiagabine on sleep onset, sleep duration, nighttime awakenings, self-reported sleep ratings, and ratings of restorative or refreshing sleep.[5][28][29][30][31] Tiagabine has been found to decrease the cognitive impairment and high cortisol levels caused by sleep restriction, with this being related to the drug's SWS improvement.[5][32][25][33] On the other hand, despite increasing SWS, tiagabine did not improve memory consolidation.[34]

The effects of tiagabine on sleep, for instance primarily increasing SWS, resemble those of gaboxadol and muscimol but are very different from those of conventional GABAA receptor positive allosteric modulators like benzodiazepines and Z drugs.[18][15][5][19][10][13][35]

The American Academy of Sleep Medicine's 2017 clinical practice guidelines recommended against the use of tiagabine in the treatment of insomnia due to limited effectiveness and very low quality of evidence.[6]

Anxiety disorders

Tiagabine may be prescribed off-label to treat certain anxiety disorders, such as panic disorder and social anxiety disorder.[36][37][38] Tiagabine may be used alongside selective serotonin reuptake inhibitors (SSRIs), serotonin–norepinephrine reuptake inhibitors (SNRIs), or benzodiazepines for anxiety.[36] The drug was ineffective for generalized anxiety disorder.[39][40][41]

Neuropathic pain

Tiagabine can be used in the treatment of neuropathic pain.[42][43][36] It can be used alongside antidepressants, gabapentin, other anticonvulsants, or opioids for neuropathic pain.[36]

Available forms

Tiagabine is available in the form of 2, 4, 5, 10, 12, 15, and 16 mg oral tablets.[2][1] The drug is taken 1 to 4 times per day due to its short elimination half-life.[3] A sustained-release formulation would be advantageous but has not been developed or marketed.[2][14]

Contraindications

Contraindications of tiagabine include hypersensitivity (drug allergy) to tiagabine or its ingredients and severe hepatic impairment.[1][3] The drug should be avoided in pregnant and nursing women.[1][3]

Side effects

Side effects of tiagabine are dose-related.[24] The most common side effect of tiagabine is dizziness.[44] Other side effects that have been observed with a rate of statistical significance relative to placebo include asthenia, somnolence, nervousness, memory impairment, tremor, headache, diarrhea, and depression.[3][44][45] Adverse effects such as confusion, aphasia, stuttering, and paresthesia (a tingling sensation in the body's extremities, particularly the hands and fingers) may occur at higher dosages of the drug (e.g., over 8 mg/day).[44] Tiagabine has been associated with new-onset seizures and status epilepticus in people without epilepsy in post-marketing surveillance.[1][36] This may be dose-related, although it has been reported at doses of as low as 4 mg/day, and may also be related to concomitant use of other medications that lower the seizure threshold.[1][36] Some of these seizures occurred around the time of dose increases.[1] There may be an increased risk of psychosis with tiagabine treatment, although data is mixed and inconclusive.[46][47] Tiagabine can also reportedly interfere with visual color perception.[46] It has not been found to cause psychomotor, cognitive, or memory impairment.[3][2] Unlike certain other GABAergic drugs like muscimol, gaboxadol, and CI-966, tiagabine has not been associated with hallucinogenic effects.[48][49]

Overdose

Tiagabine overdose can produce neurological symptoms such as lethargy, single or multiple seizures, status epilepticus, coma, confusion, agitation, tremors, dizziness, dystonias, abnormal posturing, and hallucinations, as well as respiratory depression, tachycardia, and hypertension or hypotension.[1][50] Overdose may be fatal especially if the victim presents with severe respiratory depression or unresponsiveness.[50]

Interactions

Combination of tiagabine with enzyme-inducing anticonvulsants like carbamazepine, phenytoin, primidone, and phenobarbital can decrease the elimination half-life of tiagabine to as low as 2 to 3 hours.[3][2][1] Conversely, tiagabine does not significantly affect the hepatic metabolism of other anticonvulsants such as carbamazepine, phenytoin, and valproic acid.[3][1] Other interactions have also been reviewed.[3][1]

Pharmacology

Pharmacodynamics

Tiagabine acts a selective GABA transporter 1 (GAT-1) blocker and hence as a GABA reuptake inhibitor (GRI).[2][3][11][1] The GAT-1 is one of at least four distinct GABA transporters (GATs), with the GAT-1 being the predominant subtype in the brain, accounting for 85% of GATs in this part of the body, and thought to be responsible for most γ-aminobutyric acid (GABA) reuptake in synapses.[3][11][51] The drug has more than 1,000-fold selectivity for the GAT-1 over the GABA transporter 2 (GAT-2), GABA transporter 3 (GAT-3), and betaine/GABA transporter (BGT-1; GAT-4).[11][12][52] It also shows no significant affinity for GABA receptors or numerous other targets.[14] In addition, it does not affect key cardiac ion channels.[53] Through GAT-1 blockade, tiagabine increases levels of GABA, the major inhibitory neurotransmitter in the central nervous system, and consequently increases GABA receptor activation and GABAergic signaling, including of both GABAA and GABAB receptors.[13][16][17][14][54] The drug has been found to increase GABAergic signaling in the hippocampus, globus pallidus, ventral pallidum, and substantia nigra in animals.[1] It produces anticonvulsant, neuroprotective, hypnotic, analgesic, and anxiolytic-like effects in animals.[3][11][1]

In rodent drug discrimination tests, tiagabine partially substituted for muscimol and diazepam but did not substitute for gaboxadol, phenobarbitol, or zolpidem.[51][55][56][57][58] When tiagabine was used as the training drug however, gaboxadol near-fully substituted for tiagabine.[51] Similarly, indiplon partially substituted for tiagabine.[51] On the other hand, zolpidem, eszopiclone, baclofen, and gabapentin all did not substitute for tiagabine.[51] The GABAA receptor antagonist (+)-bicuculline at non-convulsant doses partially antagonized tiagabine's interoceptive effects, whereas higher doses that might more fully antagonize its cue were not assessed due to risk of convulsions.[51] These findings suggest involvement of the GABAA receptor in the subjective effects of tiagabine, at least in rodents.[51] Conversely, the GABAB receptor does not appear to be involved.[51]

Tiagabine increases benzodiazepines' affinity to cortical and limbic GABAA receptors and influences electroencephalography (EEG) measurements by increasing frontal activity and reducing posterior activity in the brain.[59][60]

With regard to pharmacophore, the most stable binding mode of tiagabine in the GAT-1 is that where the nipecotic acid fragment is located in the main ligand binding site, and aromatic thiophene rings are arranged within the allosteric site, which yields GAT-1 in an outward-open state.[61] This interaction is mediated through GAT-1's sodium ion mimicry, hydrogen bonding and hydrophobic interactions.[61]

Tiagabine (15 mg) enhances MEG delta power in healthy volunteers.

Tiagabine enhances the power of cortical delta (< 4 Hz) oscillations up to 1,000% relative to placebo, which may result in an EEG or MEG signature resembling non-rapid eye movement (NREM) sleep even while the person who has taken tiagabine is awake and conscious.[62] This demonstrates that cortical delta activity and wakeful consciousness are not mutually exclusive, i.e., high amplitude delta oscillations are not always a reliable indicator of unconsciousness.[62]

Pharmacokinetics

Absorption

Tiagabine is nearly completely absorbed (>95%) and has an oral bioavailability of 90%.[1][3] The time to peak levels is approximately 1 hour, with a range of 0.8 to 1.5 hours.[3] Peak levels occur after 45 minutes in a fasted state and after 2.5 hours when taken with a high-fat meal.[1][3] A high fat meal decreases peak levels by 40% but does not affect area-under-the-curve levels, indicating that it delays absorption but does not reduce the extent of absorption.[1][3] Tiagabine was administered with food in clinical trials and it is recommended that it be taken with food.[1][3] The pharmacokinetics of tiagabine are linear over a dose range of 2 to 24 mg.[1][3] Steady-state levels are achieved after 2 days of continuous dosing and there is no accumulation with repeated administration.[1][3] There have been found to be secondary peaks in circulating tiagabine levels which is suggestive of enterohepatic recycling.[3][63][64]

Distribution

Tiagabine is widely distributed through the body.[3] Its volume of distribution is approximately 1 L/kg.[3] The drug readily crosses the blood–brain barrier.[3] The plasma protein binding of tiagabine is 96%, mainly to albumin and α1-acid glycoprotein.[1]

Metabolism

The metabolism of tiagabine has not been fully characterized.[1] In any case, it is metabolized by at least two known pathways.[1] One is thiophene ring oxidation resulting in 5-oxotiagabine and the other is glucuronidation.[1] 5-Oxotiagabine is said not to contribute to the pharmacodynamics of tiagabine.[1] In-vitro studies suggest that tiagabine is metabolized primarily by the cytochrome P450 enzyme CYP3A4, although involvement of other enzymes like CYP1A2, CYP2D6, or CYP2C19 has not been excluded.[1] Two other metabolites of tiagabine have yet to be identified.[3]

Elimination

Tiagabine is excreted about 2% unchanged.[1][3] About 25% is excreted in urine and 63% is excreted in feces.[1][3] The elimination half-life of tiagabine is 4.5 to 9.0 hours.[1][3] The half-life of tiagabine was found to be decreased by 50 to 65% to 3.8 to 4.9 hours (range 2–5 hours) in patients whose hepatic enzymes had been induced with other anticonvulsants including carbamazepine, phenytoin, primidone, and phenobarbital.[1][3][21] In addition, the half-life of tiagabine is extended to 11.7 to 15.9 hours in hepatic dysfunction.[3][21] These settings as such may require dose adjustment.[1][3][21]

Chemistry

Tiagabine, also known as (–)-(R)-1-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]nipecotic acid, is a GABA analogue and a derivative of nipecotic acid.[3][1] Being a nipecotic acid derivative, introduction of 4,4-diphenylbut-3-enyl and 4,4-bis(3-methylthiophene-1-yl)but-3-enyl side chain increased lipophilicity compared to the parent compound, allowing blood–brain barrier permeability and GABA transporter 1 (GAT-1) selectivity.[2][3][65] The experimental log P of tiagabine is 2.6.[66][67] Analogues of tiagabine include CI-966, NNC-711, and SKF-89976A, among others.[11][52]

History

Tiagabine was discovered at Novo Nordisk in Denmark in 1988 by a team of medicinal chemists and pharmacologists under the general direction of Claus Bræstrup.[20] The drug was co-developed with Abbott Laboratories, in a 40/60 cost sharing deal, with Abbott paying a premium for licensing the IP from the Danish company. It was approved for treatment of epilepsy in the United States in September 1997.[21] In 2005, a bolded warning was added to the labeling of tiagabine by the United States Food and Drug Administration cautioning about association of new-onset seizures in people without epilepsy and discouraging off-label use.[9][10] Tiagabine was previously subject to Risk Evaluation and Mitigation Strategies (REMS) in the United States, which was instituted in 2010.[4][68] However, this requirement was eliminated in 2012.[69] United States patents on tiagabine listed in the Orange Book expired in April 2016.[70]

Society and culture

Availability

Tiagabine is available in countries throughout the world including Austria, Denmark, France, Germany, Spain, Switzerland, the United Kingdom, and the United States.[71]

Tiagabine is a prescription-only medication but not an otherwise controlled substance in the United States.[23]

Research

In addition to epilepsy, tiagabine was under formal clinical development for the treatment of anxiety disorders, insomnia, and neuropathic pain.[4] However, development for all of these indications was discontinued.[4] There have also been case reports and case series of tiagabine for treatment of bipolar disorder, though no clinical trials have been conducted.[72][73][74][75] The drug has been studied for treatment of post-traumatic stress disorder (PTSD).[76][77][78][79][80][81] It has been studied for treatment of aggression.[82][83][84][85]

See also

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 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33 1.34 "Gabitril (tiagabine hydrochloride) prescribing information". U.S. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/020646s021lbl.pdf. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 "[Drug Profile:] Tiagabine". Lancet 351 (9097): 203–207. January 1998. doi:10.1016/S0140-6736(97)05035-6. PMID 9449883. 
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 3.25 3.26 3.27 3.28 3.29 3.30 3.31 3.32 3.33 3.34 3.35 "Tiagabine. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic potential in the management of epilepsy". Drugs 55 (3): 437–460. March 1998. doi:10.2165/00003495-199855030-00013. PMID 9530548. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 "Tiagabine". 24 October 2021. https://adisinsight.springer.com/drugs/800001613. 
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 "Enhancement of slow wave sleep: implications for insomnia". J Clin Sleep Med 5 (2 Suppl): S27–S32. April 2009. doi:10.5664/jcsm.5.2S.S27. PMID 19998872. 
  6. ↑ 6.0 6.1 6.2 "Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia in Adults: An American Academy of Sleep Medicine Clinical Practice Guideline". Journal of Clinical Sleep Medicine 13 (2): 307–349. February 2017. doi:10.5664/jcsm.6470. PMID 27998379. 
  7. ↑ 7.0 7.1 "Insomnia in Elderly Patients: Recommendations for Pharmacological Management". Drugs Aging 35 (9): 791–817. September 2018. doi:10.1007/s40266-018-0569-8. PMID 30058034. 
  8. ↑ "Tiagabine in anxiety disorders". Expert Opin Pharmacother 7 (14): 1977–1987. October 2006. doi:10.1517/14656566.7.14.1977. PMID 17020423. 
  9. ↑ 9.0 9.1 "Emerging pharmacotherapeutic agents for insomnia: a hypnotic panacea?". Expert Opin Pharmacother 7 (13): 1731–1738. September 2006. doi:10.1517/14656566.7.13.1731. PMID 16925500. "In 2005, the FDA announced that a bolded warning would be added to the labelling for tiagabine, to inform prescribers of the risk of seizures in those without epilepsy who were being treated with the medication; therefore, off-label use of tiagabine was discouraged.". 
  10. ↑ 10.0 10.1 10.2 "Pharmacotherapy of insomnia". Expert Opin Pharmacother 13 (9): 1243–1260. June 2012. doi:10.1517/14656566.2012.683860. PMID 22578014. "5.1 Tiagabine and gaboxadol Two agents recently developed which have very distinct mechanisms of action are tiagabine (Gabitril, Cephalon [60]), which blocks synaptic GABA re-uptake, and gaboxadol, a selective extrasynaptic GABAA receptor agonist. [...] However, it should be mentioned that in 2005, the FDA issued a warning for de novo occurrence of seizures in patients without epilepsy, discouraging off-label use of this drug.". 
  11. ↑ 11.0 11.1 11.2 11.3 11.4 11.5 "Basic mechanisms of gabitril (tiagabine) and future potential developments". Epilepsia 40 (Suppl 9): S2–S6. 1999. doi:10.1111/j.1528-1157.1999.tb02087.x. PMID 10612355. 
  12. ↑ 12.0 12.1 "The GABA transporter and its inhibitors". Curr Med Chem 7 (10): 1063–1079. October 2000. doi:10.2174/0929867003374363. PMID 10911018. 
  13. ↑ 13.0 13.1 13.2 13.3 13.4 "Role of GABAA receptors in the physiology and pharmacology of sleep". Eur J Neurosci 29 (9): 1779–1794. May 2009. doi:10.1111/j.1460-9568.2009.06716.x. PMID 19473233. "Another compound, tiagabine, has been recently investigated for its potential as a hypnotic. Tiagabine is a GABA uptake inhibitor launched initially as an anticonvulsant in the treatment of epilepsy. It specifically inhibits the GABA transporter GAT-1 (Fig. 1). Such pharmacological manipulation may sustain synaptically-released GABA levels in the synaptic cleft, thereby increasing GABAA-mediated inhibition as well as activation of GABAB receptors. The effects of tiagabine on sleep are similar to those evoked by selective GABAA agonists. Indeed, tiagabine elevates EEG power density in frequencies < 10 Hz during NREM sleep, including the SWA range (Mathias et al., 2001b), and increases sleep continuity and time spent in NREM sleep stage 3–4 (Mathias et al., 2001b; Walsh et al., 2005, 2006a,b; Roth et al., 2006). [...] High-amplitude EEG spike-waves seem to be a common feature of drugs enhancing GABAA-mediated tonic conductance (Fig. 3). Muscimol, another selective GABAA agonist showing very high affinity for δ-containing receptors (Quirk et al., 1995; Huh et al., 1996; Mihalek et al., 1999), induced such EEG patterns in several species (Pedley et al., 1979; Fariello et al., 1981; Peeters et al., 1989; Lancel et al., 1996, 1997; Vyazovskiy et al., 2007). Tiagabine has been reported to elicit similar alterations of the EEG (Walton et al., 1994; Coenen et al., 1995; Lancel et al., 1998).". 
  14. ↑ 14.0 14.1 14.2 14.3 14.4 Cite error: Invalid <ref> tag; no text was provided for refs named Brodie_1995
  15. ↑ 15.0 15.1 15.2 Bateson, Alan N. (2006). "Further potential of the GABA receptor in the treatment of insomnia". Sleep Medicine 7: S3–S9. doi:10.1016/j.sleep.2006.03.001. https://linkinghub.elsevier.com/retrieve/pii/S1389945706000669. Retrieved 17 January 2026. 
  16. ↑ 16.0 16.1 "Sleep disturbances, psychiatric disorders, and psychotropic drugs". Dialogues Clin Neurosci 7 (4): 323–334. 2005. doi:10.31887/DCNS.2005.7.4/lstaner. PMID 16416708. "Other compounds enhancing GABAergic transmission could be valuable hypnotic drugs, some of which are currently in development.The drugs in question are another α1-containing GABAA-enhancing drug (indiplon), GABA analogues such as gabapentin, a GABA reuptake inhibitor (tiagabine), and a GABAA agonist (gaboxadol).96 These agents, except gaboxadol, nonspecifically enhance GABAergic transmission through GABAA, GABAB, and GABAC receptors. It should be stressed that the hypnotic effects of GABAB and GABAC ligands are not qualitatively similar to those obtained with GABAA ligands.97". 
  17. ↑ 17.0 17.1 "Slow wave activity during sleep: functional and therapeutic implications". Neuroscientist 16 (6): 618–633. December 2010. doi:10.1177/1073858410377064. PMID 20921564. "Pharmacological manipulation of GABAergic neurotransmission has diverse and complex effects on SWA. GABA agonists, such as muscimol and THIP (Gaboxadol) and the GABA uptake inhibitor tiagabine, increase SWA and SWS sleep time (Lancel and others 1998; Lancel 1999; Walsh and others 2006). Conversely, compounds that influence GABA receptor open-time (barbiturates, benzodiazepines, and to a lesser extent nonbenzodiazepines) reduce SWA and increase TC spindling (Lancel 1999). [...] It is also not entirely clear why benzodiazepines reduce SWA, while compounds like THIP and tiagabine increase SWA. [...] In particular, benzodiazepines act as allosteric positive modulators of GABAA receptors to enhance GABAA receptor-mediated chloride conductance. This conductance will shunt currents that mediate burst pause activity at a cellular level, thus reducing the tendency to generate SWA. Both THIP and tiagabine will increase extracellular GABA that will affect not only GABAA receptors but GABAB receptors as well. [...] Interestingly, pharmacological intensification of SWA leads to a dissociation between the restorative features of sleep and indices of sleep homeostasis. For example, tiagabine treatment increases SWS time (SWA was not reported) and relieves cognitive impairments normally observed during a sleep restriction protocol. However, placebo and tiagabine groups were equally sleepy, as measured by subjective ratings, the multiple-sleep-latency test, and changes in recovery sleep (Walsh and others 2006). Conversely, gaboxodol treatment (under the same protocol) increases SWS time to a similar degree (and intensifies SWA), but has seemingly opposite effects on daytime function and sleep pressure. In this case, gaboxodol reduces subjective and objective ratings of sleepiness without improving daytime cognitive performance (relative to placebo; Walsh and others 2008).". 
  18. ↑ 18.0 18.1 "Neurochemical regulation of sleep". J Psychiatr Res 41 (7): 537–552. October 2007. doi:10.1016/j.jpsychires.2006.04.007. PMID 16777143. "The effects of the GABA-uptake inhibitor tiagabine on sleep EEG resemble those of GABAA agonists. [...] Since the effects of tiagabine on sleep EEG are very similar to those after GABA agonists it appears likely that their influence on sleep may be due to tonic stimulation of GABAA receptors. The hypnotic properties of gaboxadol and tiagabine differ considerably from those of the agonistic modulators, benzodiazepines, zolpidem and zopiclone. In contrast to the latter substances these drugs mimic the sleep-promoting effect of sleep deprivation. These substances appear to represent a new class of hypnotics.". 
  19. ↑ 19.0 19.1 "Slow-wave sleep deficiency and enhancement: implications for insomnia and its management". World J Biol Psychiatry 11 (Suppl 1): 22–28. June 2010. doi:10.3109/15622971003637645. PMID 20509829. "It is well established that benzodiazepines and to a lesser extent the Z-drugs, like zolpidem and zopiclone, suppress SWA and low-frequency EEG activity in the EEG during nonREM sleep and enhance high-frequency activity, in particular in the frequency range of sleep spindles (Lancel 1999). However, several compounds have been shown to ncrease SWS including, GAT-1 inhibitors, such as tiagabine (Mathias et al. 2001), GABA-A agonists such as gaboxadol, which bind to the extrasynaptic GABA-A receptor (Walsh et al. 2007; Dijk et al. 2009b), GABA-B modulators, such as GHB (Pardi and Black 2006) and 5HT 2A antagonists such as seganserin and eplivanserin (Dijk et al. 1989a; Landolt et al. 1999). [...] Tiagabine, a GAT-1 inhibitor, increases SWS in a dose-dependent manner, with a corresponding signifi cant reduction in stage 1 sleep, in both adults (Walsh et al. 2006) and elderly patients (Roth et al. 2006) with primary insomnia. Despite this increase in SWS, traditional efficacy measures such as sleep latency or number of awakenings were unaffected in both studies (Roth et al. 2006; Walsh et al. 2006).". 
  20. ↑ 20.0 20.1 "The synthesis of novel GABA uptake inhibitors. 1. Elucidation of the structure-activity studies leading to the choice of (R)-1-[4,4-bis(3-methyl-2-thienyl)-3-butenyl]-3-piperidinecarboxylic acid (tiagabine) as an anticonvulsant drug candidate". Journal of Medicinal Chemistry 36 (12): 1716–1725. June 1993. doi:10.1021/jm00064a005. PMID 8510100. 
  21. ↑ 21.0 21.1 21.2 21.3 21.4 "Tiagabine: a novel antiepileptic drug". Ann Pharmacother 32 (11): 1173–1180. November 1998. doi:10.1345/aph.18053. PMID 9825084. 
  22. ↑ "Generic Gabitril Availability & Release Date". 8 January 2026. https://www.drugs.com/availability/generic-gabitril.html. 
  23. ↑ 23.0 23.1 "Erowid Tiagabine (Gabitril) Vault : Law". 10 May 2016. https://www.erowid.org/pharms/tiagabine/tiagabine_law.shtml. 
  24. ↑ 24.0 24.1 "Tiagabine", LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases), 2012, PMID 31643697, https://www.ncbi.nlm.nih.gov/books/NBK548376/, retrieved 2021-12-24 
  25. ↑ 25.0 25.1 25.2 "Sustaining neurobehavioral performance on less sleep: is SWS enhancement the key?:". Sleep Deprivation, Stimulant Medications, and Cognition. Cambridge University Press. 23 August 2012. p. 223–236. doi:10.1017/cbo9780511783005.018. ISBN 978-0-511-78300-5. https://www.cambridge.org/core/product/identifier/9780511783005%23c00409-3638/type/book_part. Retrieved 17 January 2026. 
  26. ↑ "Pharmacological treatment of sleep disorders and its relationship with neuroplasticity". Curr Top Behav Neurosci 25: 503–553. 2015. doi:10.1007/7854_2014_365. PMID 25585962. "Tiagabine, an adjuvant anticonvulsant, inhibits GABA transporter GAT1 and increases the inhibitory actions of GABA (Buysse 2011). Doses of 4–16 mg have been utilized to treat insomnia. [...]". 
  27. ↑ "Pharmacological Treatment of Insomnia". Clinical Handbook of Insomnia. Cham: Springer International Publishing. 2017. pp. 97–132. doi:10.1007/978-3-319-41400-3_7. ISBN 978-3-319-41398-3. http://link.springer.com/10.1007/978-3-319-41400-3_7. Retrieved 17 January 2026. 
  28. ↑ 28.0 28.1 28.2 "Tiagabine enhances slow wave sleep and sleep maintenance in primary insomnia". Sleep Med 7 (2): 155–161. March 2006. doi:10.1016/j.sleep.2005.05.004. PMID 16260179. 
  29. ↑ 29.0 29.1 29.2 "Tiagabine increases slow-wave sleep in a dose-dependent fashion without affecting traditional efficacy measures in adults with primary insomnia". J Clin Sleep Med 2 (1): 35–41. January 2006. PMID 17557435. 
  30. ↑ 30.0 30.1 30.2 "Dose-response effects of tiagabine on the sleep of older adults". Sleep 28 (6): 673–676. June 2005. doi:10.1093/sleep/28.6.673. PMID 16477953. 
  31. ↑ 31.0 31.1 31.2 "Effect of tiagabine on sleep in elderly subjects with primary insomnia: a randomized, double-blind, placebo-controlled study". Sleep 29 (3): 335–341. March 2006. doi:10.1093/sleep/29.3.335. PMID 16553019. 
  32. ↑ "Can Slow-Wave Sleep Enhancement Improve Memory? A Review of Current Approaches and Cognitive Outcomes". Yale J Biol Med 92 (1): 63–80. March 2019. PMID 30923474. 
  33. ↑ "Tiagabine is associated with sustained attention during sleep restriction: evidence for the value of slow-wave sleep enhancement?". Sleep 29 (4): 433–443. April 2006. PMID 16676776. 
  34. ↑ "Slow wave sleep induced by GABA agonist tiagabine fails to benefit memory consolidation". Sleep 36 (9): 1317–1326. September 2013. doi:10.5665/sleep.2954. PMID 23997364. 
  35. ↑ "The GABA uptake inhibitor tiagabine promotes slow wave sleep in normal elderly subjects". Neurobiol Aging 22 (2): 247–253. 2001. doi:10.1016/s0197-4580(00)00232-3. PMID 11182474. 
  36. ↑ 36.0 36.1 36.2 36.3 36.4 36.5 Stahl's essential psychopharmacology: the prescriber's guide; antipsychotics and mood stabilizers (3rd ed.). New York, NY: Cambridge University Press. 2009. pp. 523–526. ISBN 978-0-521-75900-7. 
  37. ↑ "New frontiers in the pharmacological treatment of social anxiety disorder in adults: an up-to-date comprehensive overview". Expert Opin Pharmacother 24 (2): 207–219. February 2023. doi:10.1080/14656566.2022.2159373. PMID 36519357. 
  38. ↑ "Tiagabine for social anxiety disorder". Hum Psychopharmacol 22 (4): 241–244. June 2007. doi:10.1002/hup.846. PMID 17476705. 
  39. ↑ "Pharmacological Treatment of Generalised Anxiety Disorder: Current Practice and Future Directions". Expert Rev Neurother 23 (6): 535–548. June 2023. doi:10.1080/14737175.2023.2211767. PMID 37183813. "2.10. Anticonvulsants The anticonvulsant tiagabine acts through selective inhibition of the GABA transporter (GAT-1), increasing extracellular GABA concentrations [45]. It has been investigated in five RCTs of GAD, but without evidence to support efficacy over placebo [18].". 
  40. ↑ "Tiagabine in adult patients with generalized anxiety disorder: results from 3 randomized, double-blind, placebo-controlled, parallel-group studies". J Clin Psychopharmacol 28 (3): 308–316. June 2008. doi:10.1097/JCP.0b013e318172b45f. PMID 18480688. 
  41. ↑ "The selective GABA reuptake inhibitor tiagabine for the treatment of generalized anxiety disorder: results of a placebo-controlled study". J Clin Psychiatry 66 (11): 1401–1408. November 2005. doi:10.4088/jcp.v66n1109. PMID 16420077. 
  42. ↑ "Newer anticonvulsant drugs in neuropathic pain and bipolar disorder". J Pain Palliat Care Pharmacother 16 (4): 19–37. 2002. doi:10.1080/j354v16n04_03. PMID 14635823. 
  43. ↑ "Use of anticonvulsants for treatment of neuropathic pain". Neurology 59 (5 Suppl 2): S14–S17. September 2002. doi:10.1212/wnl.59.5_suppl_2.s14. PMID 12221151. 
  44. ↑ 44.0 44.1 44.2 "Tiagabine: the safety landscape". Epilepsia 36 (Suppl 6): S10–S13. 1995. doi:10.1111/j.1528-1157.1995.tb06009.x. PMID 8595787. 
  45. ↑ Antiepileptic Drugs: Pharmacology and Therapeutics. Springer Science & Business Media. 6 December 2012. pp. 459–. ISBN 978-3-642-60072-2. https://books.google.com/books?id=8iv6CAAAQBAJ&pg=PA459. 
  46. ↑ 46.0 46.1 Cite error: Invalid <ref> tag; no text was provided for refs named Leduc_2012
  47. ↑ "Antihistamines". Meyler's Side Effects of Psychiatric Drugs. Elsevier. 2009. pp. 652–. ISBN 978-0-444-53266-4. https://books.google.com/books?id=AmYFTSO8jCkC&pg=PA652. 
  48. ↑ "Gaboxadol--a new awakening in sleep". Curr Opin Pharmacol 6 (1): 30–36. February 2006. doi:10.1016/j.coph.2005.10.004. PMID 16368265. "[...] tiagabine (GABA uptake inhibitor), valproate, gabapentin and progabide all increase CNS levels of GABA and yet are not associated with hallucinogenic side effects [28].". 
  49. ↑ Hollister, Leo E. (1990). "New class of hallucinogens: GABA-enhancing agents". Drug Development Research 21 (3): 253–256. doi:10.1002/ddr.430210311. ISSN 0272-4391. "GABA-enhancing drugs, such as muscimol and Cl-966, produce mental states that differ in various ways from those of other hallucinogens. [...] Finally, we have a new group of hallucinogens, which act either as GABA uptake inhibitors or GABA, agonists. Muscimol is one of the materials derived from Amanita muscuria, along with muscarine. [...]". 
  50. ↑ 50.0 50.1 "Retrospective evaluation of tiagabine overdose". Clinical Toxicology 43 (7): 855–859. 2009. doi:10.1080/15563650500357529. PMID 16440513. 
  51. ↑ 51.0 51.1 51.2 51.3 51.4 51.5 51.6 51.7 "Discriminative stimulus effects of tiagabine and related GABAergic drugs in rats". Psychopharmacology (Berl) 197 (4): 591–600. May 2008. doi:10.1007/s00213-008-1077-z. PMID 18264695. "Tiagabine potently blocks reuptake at the GAT-1 GABA transporter, which is the predominant (85% belong to this type) GABA transporter in the brain (Borden et al. 1994).". 
  52. ↑ 52.0 52.1 "Tiagabine, SK&F 89976-A, CI-966, and NNC-711 are selective for the cloned GABA transporter GAT-1". Eur J Pharmacol 269 (2): 219–224. October 1994. doi:10.1016/0922-4106(94)90089-2. PMID 7851497. 
  53. ↑ "Antiepileptic Drug Tiagabine Does Not Directly Target Key Cardiac Ion Channels Kv11.1, Nav1.5 and Cav1.2". Molecules 26 (12): 3522. June 2021. doi:10.3390/molecules26123522. PMID 34207748. 
  54. ↑ "The selective GABA reuptake inhibitor tiagabine for the treatment of generalized anxiety disorder: results of a placebo-controlled study". The Journal of Clinical Psychiatry 66 (11): 1401–1408. November 2005. doi:10.4088/JCP.v66n1109. PMID 16420077. 
  55. ↑ "Gaboxadol, a selective extrasynaptic GABA(A) agonist, does not generalise to other sleep-enhancing drugs: a rat drug discrimination study". Neuropharmacology 52 (3): 844–853. March 2007. doi:10.1016/j.neuropharm.2006.10.009. PMID 17196996. 
  56. ↑ "Characterization of tiagabine (NO-328), a new potent and selective GABA uptake inhibitor". Eur J Pharmacol 196 (3): 257–266. April 1991. doi:10.1016/0014-2999(91)90438-v. PMID 1832636. 
  57. ↑ "Muscimol-like discriminative stimulus effects of GABA agonists in rats". Pharmacol Biochem Behav 59 (2): 319–326. February 1998. doi:10.1016/s0091-3057(97)00413-9. PMID 9476976. 
  58. ↑ "Discriminative stimulus effects of presynaptic GABA agonists in pentobarbital-trained rats". Pharmacol Biochem Behav 47 (1): 5–11. January 1994. doi:10.1016/0091-3057(94)90104-x. PMID 8115428. 
  59. ↑ "[11Cflumazenil binding is increased in a dose-dependent manner with tiagabine-induced elevations in GABA levels"]. PLOS ONE 7 (2). 2012. doi:10.1371/journal.pone.0032443. PMID 22384252. Bibcode: 2012PLoSO...732443F. 
  60. ↑ "Tiagabine induced modulation of oscillatory connectivity and activity match PET-derived, canonical GABA-A receptor distributions". European Neuropsychopharmacology 50: 34–45. September 2021. doi:10.1016/j.euroneuro.2021.04.005. PMID 33957336. 
  61. ↑ 61.0 61.1 "Analysis of Different Binding Modes for Tiagabine within the GAT-1 Transporter". Biomolecules 12 (11): 1663. November 2022. doi:10.3390/biom12111663. PMID 36359013. 
  62. ↑ 62.0 62.1 "Paradoxical pharmacological dissociations result from drugs that enhance delta oscillations but preserve consciousness". Communications Biology 6 (1). June 2023. doi:10.1038/s42003-023-04988-8. PMID 37340024. 
  63. ↑ "Pharmacokinetics of tiagabine, a gamma-aminobutyric acid-uptake inhibitor, in healthy subjects after single and multiple doses". Epilepsia 36 (6): 605–611. June 1995. doi:10.1111/j.1528-1157.1995.tb02575.x. PMID 7555975. 
  64. ↑ "Pharmacokinetics and safety of tiagabine in subjects with various degrees of hepatic function". Epilepsia 38 (4): 445–451. April 1997. doi:10.1111/j.1528-1157.1997.tb01734.x. PMID 9118850. 
  65. ↑ "Rational approaches for the design of various GABA modulators and their clinical progression". Molecular Diversity 25 (1): 551–601. February 2021. doi:10.1007/s11030-020-10068-4. PMID 32170466. 
  66. ↑ "Tiagabine". https://pubchem.ncbi.nlm.nih.gov/compound/60648. 
  67. ↑ "Tiagabine: Uses, Interactions, Mechanism of Action". 1 April 2001. https://go.drugbank.com/drugs/DB00906. 
  68. ↑ "Supplement Approval". https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2010/020646s017ltr.pdf. 
  69. ↑ "Supplement approval - Release REMS requirement". https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2012/020646s020ltr.pdf. 
  70. ↑ "Search Results for Tiagabine". Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. U.S. Food and Drug Administration. http://www.accessdata.fda.gov/scripts/cder/ob/docs/obdetail.cfm?Appl_No=020646&TABLE1=OB_Rx. 
  71. ↑ Index Nominum 2000: International Drug Directory. Taylor & Francis. 2000. ISBN 978-3-88763-075-1. https://books.google.com/books?id=5GpcTQD_L2oC&pg=PA1023. Retrieved 17 January 2026. 
  72. ↑ "Tiagabine in the maintenance treatment of bipolar disorder". Cochrane Database Syst Rev 2011 (12). December 2011. doi:10.1002/14651858.CD005173.pub3. PMID 22161389. 
  73. ↑ "Tiagabine for acute affective episodes in bipolar disorder". Cochrane Database Syst Rev 12 (12). December 2012. doi:10.1002/14651858.CD004694.pub3. PMID 23235614. 
  74. ↑ "A systematic review on the role of anticonvulsants in the treatment of acute bipolar depression". Int J Neuropsychopharmacol 16 (2): 485–496. March 2013. doi:10.1017/S1461145712000491. PMID 22575611. 
  75. ↑ "Is anticonvulsant treatment of mania a class effect? Data from randomized clinical trials". CNS Neurosci Ther 17 (3): 167–177. June 2011. doi:10.1111/j.1755-5949.2009.00089.x. PMID 20015083. 
  76. ↑ "Anticonvulsants to treat post-traumatic stress disorder". Hum Psychopharmacol 29 (5): 427–433. September 2014. doi:10.1002/hup.2425. PMID 25131430. 
  77. ↑ "Antiepileptic drugs for the treatment of post-traumatic stress disorder". Curr Psychiatry Rep 9 (4): 291–300. August 2007. doi:10.1007/s11920-007-0035-5. PMID 17880860. 
  78. ↑ "PSYCHOTHERAPY VERSUS PHARMACOTHERAPY FOR POSTTRAUMATIC STRESS DISORDER: SYSTEMIC REVIEW AND META-ANALYSES TO DETERMINE FIRST-LINE TREATMENTS". Depress Anxiety 33 (9): 792–806. September 2016. doi:10.1002/da.22511. PMID 27126398. 
  79. ↑ "Tiagabine for posttraumatic stress disorder: effects of open-label and double-blind discontinuation treatment". Psychopharmacology (Berl) 184 (1): 21–25. January 2006. doi:10.1007/s00213-005-0265-3. PMID 16341846. 
  80. ↑ "The efficacy and tolerability of tiagabine in adult patients with post-traumatic stress disorder". J Clin Psychopharmacol 27 (1): 85–88. February 2007. doi:10.1097/JCP.0b013e31802e5115. PMID 17224720. 
  81. ↑ "The sleep effects of tiagabine on the first night of treatment predict post-traumatic stress disorder response at three weeks". J Psychopharmacol 28 (5): 457–465. May 2014. doi:10.1177/0269881113509903. PMID 24288237. 
  82. ↑ "Pharmacologic treatment of impulsive aggression with antiepileptic drugs". Curr Treat Options Neurol 11 (5): 383–390. September 2009. doi:10.1007/s11940-009-0043-3. PMID 19744405. 
  83. ↑ "Chronic tiagabine administration and aggressive responding in individuals with a history of substance abuse and antisocial behavior". J Psychopharmacol 26 (7): 982–993. July 2012. doi:10.1177/0269881111408962. PMID 21730016. 
  84. ↑ "Effects of acute tiagabine administration on aggressive responses of adult male parolees". J Psychopharmacol 22 (2): 144–152. March 2008. doi:10.1177/0269881107078489. PMID 17715212. 
  85. ↑ "Tiagabine for rage, aggression, and anxiety". J Neuropsychiatry Clin Neurosci 17 (2): 252. 2005. doi:10.1176/jnp.17.2.252. PMID 15939984. 

Template:Insomnia medications



Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Tiagabine&oldid=4246701"