Phenobarbital, hyoscyamine, atropine, and scopolamine and Tiagabine interaction
Phenobarbital, hyoscyamine, atropine, and scopolamine and Tiagabine: the Tiagabine prescribing label mentions this combination without an instruction to avoid it or change the dose.
Mentioned, no instruction to avoid. Worth knowing; rarely a reason to change anything on its own.
What the FDA labels say
From the Tiagabine (Tiagabine Hydrochloride) label · effective 2021-09-30
…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.
Carbamazepine, phenytoin, primidone, and phenobarbital are generally classified as enzyme inducers; valproate and gabapentin are not.
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.
Phenobarbital (Primidone) : Population pharmacokinetic analyses indicate that tiagabine clearance is 60% greater in patients taking phenobarbital (primidone) with or without other enzyme-inducing AEDs.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.