Tiagabine

Tiagabine
Adult Indications & Dosage
Pediatric Indications & Dosage
Contraindications
Warnings & Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Administration & Monitoring
Overdosage
Pharmacology
Clinical Studies
How Supplied
Images
Patient Counseling Information
Precautions with Alcohol
Brand Names
Look-Alike Names

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alberto Plate [2]

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Overview

Tiagabine is {{{aOrAn}}} anticonvulsant, gamma aminobutyric acid Uptake Inhibitor that is FDA approved for the treatment of partial seizures in adults and children > 12 years. Common adverse reactions include pruritus, abdominal pain, nausea, asthenia, ataxia, confusion, disturbance in speech, dizziness, feeling nervous, insomnia, somnolence, tremor, unable to concentrate and pharyngitis.

Adult Indications and Dosage

FDA-Labeled Indications and Dosage (Adult)

There is limited information regarding Tiagabine FDA-Labeled Indications and Dosage (Adult) in the drug label.

Off-Label Use and Dosage (Adult)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Tiagabine in adult patients.

Non–Guideline-Supported Use

There is limited information regarding Off-Label Non–Guideline-Supported Use of Tiagabine in adult patients.

Pediatric Indications and Dosage

FDA-Labeled Indications and Dosage (Pediatric)

There is limited information regarding Tiagabine FDA-Labeled Indications and Dosage (Pediatric) in the drug label.

Off-Label Use and Dosage (Pediatric)

Guideline-Supported Use

There is limited information regarding Off-Label Guideline-Supported Use of Tiagabine in pediatric patients.

Non–Guideline-Supported Use

There is limited information regarding Off-Label Non–Guideline-Supported Use of Tiagabine in pediatric patients.

Contraindications

GABITRIL is contraindicated in patients who have demonstrated hypersensitivity to the drug or its ingredients.

Warnings

• Seizures in Patients Without Epilepsy: Post-marketing reports have shown that GABITRIL use has been associated with new onset seizures and status epilepticus in patients without epilepsy. Dose may be an important predisposing factor in the development of seizures, although seizures have been reported in patients taking daily doses of GABITRIL as low as 4 mg/day. In most cases, patients were using concomitant medications (antidepressants, antipsychotics, stimulants, narcotics) that are thought to lower the seizure threshold. Some seizures occurred near the time of a dose increase, even after periods of prior stable dosing.
• The GABITRIL dosing recommendations in current labeling for treatment of epilepsy were based on use in patients with partial seizures 12 years of age and older, most of whom were taking enzyme-inducing antiepileptic drugs (AEDs; e.g., carbamazepine, phenytoin, primidone and phenobarbital) which lower plasma levels of GABITRIL by inducing its metabolism. Use of GABITRIL without enzyme-inducing antiepileptic drugs results in blood levels about twice those attained in the studies on which current dosing recommendations are based.
• Safety and effectiveness of GABITRIL have not been established for any indication other than as adjunctive therapy for partial seizures in adults and children 12 years and older.
• In nonepileptic patients who develop seizures while on GABITRIL treatment, GABITRIL should be discontinued and patients should be evaluated for an underlying seizure disorder.
• Seizures and [[status[ epilepticus]] are known to occur with GABITRIL overdosage.

Suicidal Behavior and Ideation

Antiepileptic drugs (AEDs), including GABITRIL, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior.

Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide.

The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed.

The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs use for any indication. The risk did not vary substantially by age (5-100 years) in the clinical trials analyzed.

Table 4 shows absolute and relative risk by indication for all evaluated AEDs.

The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.

Anyone considering prescribing GABITRIL or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers.

Withdrawal Seizures

As a rule, antiepilepsy drugs should not be abruptly discontinued because of the possibility of increasing seizure frequency. In a placebo-controlled, double-blind, dose-response study (Study 1 described in CLINICAL STUDIES) designed, in part, to investigate the capacity of GABITRIL to induce withdrawal seizures, study drug was tapered over a 4-week period after 16 weeks of treatment. Patients’ seizure frequency during this 4-week withdrawal period was compared to their baseline seizure frequency (before study drug). For each partial seizure type, for all partial seizure types combined, and for secondarily generalized tonic-clonic seizures, more patients experienced increases in their seizure frequencies during the withdrawal period in the three GABITRIL groups than in the placebo group. The increase in seizure frequency was not affected by dose. GABITRIL should be withdrawn gradually to minimize the potential of increased seizure frequency, unless safety concerns require a more rapid withdrawal.

Cognitive/Neuropsychiatric Adverse Events

Adverse events most often associated with the use of GABITRIL were related to the central nervous system. The most significant of these can be classified into 2 general categories: 1) impaired concentration, speech or language problems, and confusion (effects on thought processes); and 2) somnolence and fatigue (effects on level of consciousness). The majority of these events were mild to moderate. In controlled clinical trials, these events led to discontinuation of treatment with GABITRIL in 6% (31 of 494) of patients compared to 2% (5 of 275) of the placebo-treated patients. A total of 1.6% (8 of 494) of the GABITRIL treated patients in the controlled trials were hospitalized secondary to the occurrence of these events compared to 0% of the placebo treated patients. Some of these events were dose related and usually began during initial titration.

Patients with a history of spike and wave discharges on EEG have been reported to have exacerbations of their EEG abnormalities associated with these cognitive/neuropsychiatric events. This raises the possibility that these clinical events may, in some cases, be a manifestation of underlying seizure activity (see PRECAUTIONS, LABORATORY TESTS, EEG). In the documented cases of spike and wave discharges on EEG with cognitive/neuropsychiatric events, patients usually continued tiagabine, but required dosage adjustment.

Additionally, there have been postmarketing reports of patients who have experienced cognitive/neuropsychiatric symptoms, some accompanied by EEG abnormalities such as generalized spike and wave activity, that have been reported as nonconvulsant status epilepticus. Some reports describe recovery following reduction of dose or discontinuation of GABITRIL.

Status Epilepticus

In the three double-blind, placebo-controlled, parallel-group studies (Studies 1, 2, and 3), the incidence of any type of status epilepticus (simple, complex, or generalized tonic-clonic) in patients receiving GABITRIL was 0.8% (4 of 494 patients) versus 0.7% (2 of 275 patients) receiving placebo. Among the patients treated with GABITRIL across all epilepsy studies (controlled and uncontrolled), 5% had some form of status epilepticus. Of the 5%, 57% of patients experienced complex partial status epilepticus. A critical risk factor for status epilepticus was the presence of a previous history; 33% of patients with a history of status epilepticus had recurrence during GABITRIL treatment. Because adequate information about the incidence of status epilepticus in a similar population of patients with epilepsy who have not received treatment with GABITRIL is not available, it is impossible to state whether or not treatment with GABITRIL is associated with a higher or lower rate of status epilepticus than would be expected to occur in a similar population not treated with GABITRIL.

Sudden Unexpected Death In Epilepsy (SUDEP)

There have been as many as 10 cases of sudden unexpected deaths during the clinical development of tiagabine among 2531 patients with epilepsy (3831 patient-years of exposure).

This represents an estimated incidence of 0.0026 deaths per patient-year. This rate is within the range of estimates for the incidence of sudden and unexpected deaths in patients with epilepsy not receiving GABITRIL (ranging from 0.0005 for the general population with epilepsy, 0.003 to 0.004 for clinical trial populations similar to that in the clinical development program for GABITRIL, to 0.005 for patients with refractory epilepsy). The estimated SUDEP rates in patients receiving GABITRIL are also similar to those observed in patients receiving other antiepilepsy drugs, chemically unrelated to GABITRIL, that underwent clinical testing in similar populations at about the same time. This evidence suggests that the SUDEP rates reflect population rates, not a drug effect.

Adverse Reactions

Clinical Trials Experience

There is limited information regarding Tiagabine Clinical Trials Experience in the drug label.

Postmarketing Experience

There is limited information regarding Tiagabine Postmarketing Experience in the drug label.

Drug Interactions

There is limited information regarding Tiagabine Drug Interactions in the drug label.

Use in Specific Populations

Pregnancy

Pregnancy Category (FDA): There is no FDA guidance on usage of Tiagabine in women who are pregnant.
Pregnancy Category (AUS): There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Tiagabine in women who are pregnant.

Labor and Delivery

There is no FDA guidance on use of Tiagabine during labor and delivery.

Nursing Mothers

There is no FDA guidance on the use of Tiagabine in women who are nursing.

Pediatric Use

There is no FDA guidance on the use of Tiagabine in pediatric settings.

Geriatic Use

There is no FDA guidance on the use of Tiagabine in geriatric settings.

Gender

There is no FDA guidance on the use of Tiagabine with respect to specific gender populations.

Race

There is no FDA guidance on the use of Tiagabine with respect to specific racial populations.

Renal Impairment

There is no FDA guidance on the use of Tiagabine in patients with renal impairment.

Hepatic Impairment

There is no FDA guidance on the use of Tiagabine in patients with hepatic impairment.

Females of Reproductive Potential and Males

There is no FDA guidance on the use of Tiagabine in women of reproductive potentials and males.

Immunocompromised Patients

There is no FDA guidance one the use of Tiagabine in patients who are immunocompromised.

Administration and Monitoring

Administration

There is limited information regarding Tiagabine Administration in the drug label.

Monitoring

There is limited information regarding Tiagabine Monitoring in the drug label.

IV Compatibility

There is limited information regarding the compatibility of Tiagabine and IV administrations.

Overdosage

There is limited information regarding Tiagabine overdosage. If you suspect drug poisoning or overdose, please contact the National Poison Help hotline (1-800-222-1222) immediately.

Pharmacology

There is limited information regarding Tiagabine Pharmacology in the drug label.

Mechanism of Action

There is limited information regarding Tiagabine Mechanism of Action in the drug label.

Structure

There is limited information regarding Tiagabine Structure in the drug label.

Pharmacodynamics

There is limited information regarding Tiagabine Pharmacodynamics in the drug label.

Pharmacokinetics

There is limited information regarding Tiagabine Pharmacokinetics in the drug label.

Nonclinical Toxicology

There is limited information regarding Tiagabine Nonclinical Toxicology in the drug label.

Clinical Studies

There is limited information regarding Tiagabine Clinical Studies in the drug label.

How Supplied

There is limited information regarding Tiagabine How Supplied in the drug label.

Storage

There is limited information regarding Tiagabine Storage in the drug label.

Images

Drug Images

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Package and Label Display Panel

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Patient Counseling Information

There is limited information regarding Tiagabine Patient Counseling Information in the drug label.

Precautions with Alcohol

Alcohol-Tiagabine interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

Brand Names

There is limited information regarding Tiagabine Brand Names in the drug label.

Look-Alike Drug Names

There is limited information regarding Tiagabine Look-Alike Drug Names in the drug label.

Drug Shortage Status

Price

References

The contents of this FDA label are provided by the National Library of Medicine.

Tiagabine

File:Tiagabine.svg
Clinical data
Pregnancy category	B3 (Au), C (U.S.)
Routes of administration	Oral
ATC code	N03AG06 (WHO)
Legal status
Legal status	POM (UK), ℞-only (U.S.)
Pharmacokinetic data
Bioavailability	90%
Protein binding	96%
Metabolism	Hepatic (CYP450 system)
Elimination half-life	7-9 hours
Excretion	Fecal and renal
Identifiers
IUPAC name (3S)-1-[4,4-bis(3-methylthiophen-2-yl)but-3-enyl] piperidine-3-carboxylic acid
CAS Number	115103-54-3
PubChem CID	60648
DrugBank	APRD00344
E number	{{#property:P628}}
ECHA InfoCard	{{#property:P2566}}
Chemical and physical data
Formula	C20H25NO2S2
Molar mass	375.55 g/mol

Tiagabine (IPA: Template:IPA) is an anti-convulsive medication produced by Cephalon Inc. and marketed under the brand name Gabitril. The medication is also used in the treatment for panic disorder as are a few other anticonvulsants.

Though the exact mechanism by which tiagabine exerts its effect on the human body is unknown, it does appear to operate as a selective GABA reuptake inhibitor.

Side effects

Tiagabine's most common side effects include confusion, difficulty speaking clearly/stuttering, mild sedation, and in doses over 8 mg, a tingling sensation (paraphasia) in the body's extremities, particularly the hands and fingers.

External links

• Gabitril (manufacturer's website)