Frequency of drug combinations between enzyme-inducing first-generation antiepileptic drugs and inducible drugs in patients with epilepsy

Epilepsy Behav. 2018 Oct:87:92-95. doi: 10.1016/j.yebeh.2018.08.004. Epub 2018 Aug 18.

Abstract

Objective: The objective of the study was to systematically assess, through the analysis of administrative data, the frequency of combinations of first-generation enzyme-inducing (EI) antiepileptic drugs (AEDs) with drugs frequently prescribed in patients with epilepsy whose metabolism is induced by EIAEDs.

Methods: From the population of Tuscany (a region in Italy of about 3,750,000 habitants), patients who had been treated with at least one first-generation EIAEDs (carbamazepine, phenytoin, phenobarbital, and primidone) and had received prescriptions of an inducible non-AED (NON-AED) included in a prespecified list of 103 inducible drugs were identified.

Results: At the index date, 9221 patients with epilepsy were treated with at least one traditional EIAED, and there were 2538 drug combinations between EIAEDs and NON-AEDs, which may result in potentially serious clinical consequences, and 3317 combinations with NON-AEDs that have their metabolism consistently increased.

Conclusions: Patients with epilepsy treated with traditional EIAEDs are at a very high risk of drug interactions.

Keywords: Administrative data; Carbamazepine; Cardiovascular diseases; Phenobarbital; Phenytoin; Primidone.

MeSH terms

  • Anticonvulsants / administration & dosage*
  • Anticonvulsants / metabolism
  • Carbamazepine / administration & dosage
  • Carbamazepine / metabolism
  • Cytochrome P-450 Enzyme Inducers / administration & dosage*
  • Cytochrome P-450 Enzyme Inducers / metabolism
  • Drug Interactions / physiology*
  • Drug Therapy, Combination
  • Epilepsy / drug therapy*
  • Epilepsy / epidemiology
  • Epilepsy / metabolism
  • Female
  • Humans
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Phenobarbital / administration & dosage
  • Phenobarbital / metabolism
  • Phenytoin / administration & dosage
  • Phenytoin / metabolism

Substances

  • Anticonvulsants
  • Cytochrome P-450 Enzyme Inducers
  • Carbamazepine
  • Phenytoin
  • Phenobarbital