Interação entre Primidona e Tiagabina

Use of tiagabine HCl without enzyme-inducing antiepileptic drugs results in blood levels about twice those attained in the studies on which current dosing recommendations are based (see DOSAGE AND ADMINISTRATION ).

Tiagabine HCl is considered to be a non-enzyme inducing AED (see PRECAUTIONS, General, Use in Non-Induced Patients ).

Phenobarbital or Primidone : No formal pharmacokinetic studies have been performed examining the addition of tiagabine to regimens containing phenobarbital or primidone.

The addition of tiagabine in a limited number of patients in three well-controlled studies caused no systematic changes in phenobarbital or primidone concentrations when compared to placebo.

…tiagabine HCl 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 tiagabine HCl by inducing its metabolism.

Neonatal hemorrhage, with a coagulation defect resembling vitamin K deficiency, has been described in newborns whose mothers were taking primidone and other anticonvulsants.