Tiagabine Hydrochloride

A to Z Drug Facts

 Action Mechanism unknown; may block GABA uptake into presynaptic neurons, allowing more GABA to be available for binding with the GABA receptor of post-synaptic cells.

 Indications Adjunctive treatment in treatment of partial seizures.

 Contraindications Standard considerations.

 Route/Dosage

ADOLESCENTS 12–18 YR: PO Initial dose 4 mg qd. Increase dose by 4 mg after 1 week and thereafter by 4–8 mg at weekly intervals until response achieved or total of 32 mg/day. ADULTS: PO Initial dose 4 mg qd. Increase by 4–8 mg at weekly intervals until response achieved or total of 56 mg/day.

 Interactions

Enzyme-inducing antiepileptic drugs (eg, carbamazepine, phenytoin, primidone, phenobarbital): Increased tiagabine clearance.

 Lab Test Interferences None well documented.

 Adverse Reactions

CNS: Dizziness; lightheadedness; somnolence; nervousness; irritability; agitation; ostility; language problem; tremor; abnormal gait; ataxia; abnormal thinking; oncentration/attention difficulty; depression; confusion; insomnia; speech disorder; difficulty with memory; paresthesia; emotional lability. DERM: Rash; pruritus; occhymosis. EENT: Nystagmus; amblyopia; pharyngitis. GI: Nausea; abdominal pain; diarrhea; vomiting; increased appetite; mouth ulceration; gingivitis. OTHER: Asthenia; lack of energy; pain; cough; myasthenia; accidental injury; nfection; flu syndrome; myalgia; urinary tract infection; vasodilation.

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Safety and efficacy in children < 12 yr not established. Hepatic function impairment: Dosage reduction or longer doing interval may be necessaryN Serious adverse effects: During clinical trials some patients experienced status epilepticus, and 10 sudden unexplained deaths occurred. The association of these events with tiagabine use is unclear. Withdrawal: Do not discontinue antiepileptic drugs abruptly because of possible increased seizure frequency on drug withdrawal. EEG: Patients with a history of spike and wave discharges on EEG may have exacerbations of EEG abnormalities associated with cognitive/neuropsychiatric events, which may be a manifestation of underlying seizure activity. Dosage reduction of tiagabine may be necessary.

 Administration/Storage

• Administer medication with food.
• Titrate dose at weekly intervals to effective or maximum dose.
• Administer initial dose as single daily dose. The total daily dose should be given as equally divided doses 2–4 times a day.
• Discontinue medication gradually over minimum of 1 wk.
• Store at room temperature, protected from light and moisture.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note hepatic function impairment and seizure pattern.
• Assess baseline vital signs.
• Assess for development of side effects. Notify physician if noted.
• Withdraw medication gradually to avoid the possibility of increasing seizure frequency.

 Patient/Family Education

• Advise patient that medication should be taken with food.
• Explain that missed dose should be taken as soon as possible but that 2 doses should not be taken together. Instruct patient to call physician if 2 or more doses are missed.
• Instruct patient to report these symptoms to physician: somnolence, excessive fatigue or weakness, dizziness, concentration or attention difficulty, difficulty with memory, speech disorder, or ataxia.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
• Advise patient to use caution when taking these other drugs with CNS depressant effects (eg, alcohol, sedatives, etc).
• Advise patient to notify their physician if they become pregnant, plan on becoming pregnant or are breastfeeding while taking this medication.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts