Multiple inductive effects of carbamazepine on combined therapy with paliperidone and amlodipine

J Clin Pharm Ther. 2015 Aug;40(4):480-2. doi: 10.1111/jcpt.12286. Epub 2015 May 26.


What is known and objective: Carbamazepine is a potent inducer of cytochrome P450 3A and P-glycoprotein. However, there are no reports of the effects of carbamazepine on more than one co-administered drug.

Case summary: A 53-year-old female patient with schizophrenia and hypertension was on paliperidone 12 mg/day and amlodipine 5 mg/day. When carbamazepine was added to this prescription, the plasma concentrations of both drugs decreased dramatically in a dose-dependent manner. Although the patient's psychotic symptoms did not change, as a result, her mean blood pressure increased to 160·1/103·6 mmHg from 138·4/91·4 mmHg at a carbamazepine dose of 600 mg/day.

What is new and conclusion: Theses cases show the effect of carbamazepine induction on two drugs simultaneously. Care is required when carbamazepine is added to drug regimens including paliperidone or amlodipine alone or together.

Keywords: CYP3A; P-glycoprotein; carbamazepine; pharmacodynamics; pharmacokinetics.

Publication types

  • Case Reports

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / drug effects
  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / metabolism
  • Amlodipine / administration & dosage
  • Amlodipine / pharmacokinetics*
  • Amlodipine / therapeutic use
  • Antipsychotic Agents / therapeutic use
  • Blood Pressure / drug effects
  • Carbamazepine / administration & dosage
  • Carbamazepine / pharmacology*
  • Carbamazepine / therapeutic use
  • Cytochrome P-450 CYP3A / drug effects
  • Cytochrome P-450 CYP3A / metabolism
  • Cytochrome P-450 CYP3A Inducers / administration & dosage
  • Cytochrome P-450 CYP3A Inducers / pharmacology
  • Cytochrome P-450 CYP3A Inducers / therapeutic use
  • Dose-Response Relationship, Drug
  • Drug Interactions
  • Female
  • Humans
  • Hypertension / drug therapy
  • Middle Aged
  • Paliperidone Palmitate / administration & dosage
  • Paliperidone Palmitate / pharmacokinetics*
  • Paliperidone Palmitate / therapeutic use
  • Schizophrenia / drug therapy


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Antipsychotic Agents
  • Cytochrome P-450 CYP3A Inducers
  • Amlodipine
  • Carbamazepine
  • Cytochrome P-450 CYP3A
  • Paliperidone Palmitate