Tiagabine hydrochloride
Tiagabine hydrochloride (Gabatril)
Tiagabine hydrochloride
(tye- AG-ah-been)
Pregnancy Category: C Gabatril (Rx)

Classification: Anticonvulsant, miscellaneous

See Also: See also Anticonvulsants.

Action/Kinetics: Mechanism not known but activity of GABA, an inhibitory neurotransmitter, may be enhanced. Drug may block uptake of GABA into presynaptic neurons allowing more GABA to bind to post-synaptic cells. This prevents propagation of neural impulses that contribute to seizures due to GABA-ergic action. Peak plasma levels: About 45 min when fasting. High fat meals decrease rate but not extent of absorption. Metabolized in liver; excreted in urine and feces. t 1/2, elimination: 7-9 hr. Diurnal effect occurs with levels being lower in evening compared with morning.

Uses: Adjunctive therapy for partial seizures.

Contraindications: Lactation.

Special Concerns: Safety and efficacy have not been determined in children less than 12 years old.

Side Effects: CNS: Dizziness, asthenia, somnolence, nervousness, tremor, insomnia, difficulty with concentration or attention, ataxia, confusion, speech disorder, difficulty with memory, paresthesia, depression, emotional lability, abnormal gait, hostility, nystagmus, problems with language, agitation. GI: N&V;, diarrhea, increased appetite, mouth ulceration. Respiratory: Pharyngitis, increased cough. Dermatologic: Rash, pruritus. Miscellaneous: Abdominal pain, unspecified pain, vasodilation, myasthenia.

Overdose Management: Symptoms: Somnolence, impaired consciousness, agitation, confusion, speech difficulties, depression, weakness, myoclonus. Treatment: Emesis or gastric lavage, maintain an airway. General supportive treatment.

Drug Interactions: Carbamazepine / Clearance due to metabolism Phenobarbital / Clearance due to metabolism Phenytoin / Clearance due to metabolism Valproate / Clearance due to metabolism

How Supplied: Tablets: 4 mg, 12 mg, 16 mg, 20 mg

Dosage
?Tablets Partial seizures.
Adults and children over 18 years, initial: 4 mg once daily. Total daily dose may be increased by 4 to 8 mg at weekly intervals until clinical effect is observed or daily dose is 56 mg/day. Children, 12 to 18 years, initial: 4 mg once daily. Total daily dose may be increased by 4 mg at beginning of week 2. Thereafter, dose may be increased by 4 to 8 mg at weekly intervals until clinical effect is seen or dose is 32 mg/day. For all ages, give total daily dose in 2 to 4 divided doses.