MajorAntiepileptics. Carboxamide derivatives×First-generation antipsychotics. Butyrophenone derivatives
Updated · Methodology
Mechanism
Carbamazepine induces CYP3A4 – a partial haloperidol clearance route. Haloperidol plasma levels fall by 50% and antipsychotic effect weakens.
Symptoms
Return of positive symptoms: hallucinations, delusions, agitation. In schizophrenia, risk of acute relapse.
Management
During carbamazepine therapy, increase haloperidol 1.5- to 2-fold under clinical monitoring. Alternative anticonvulsants without induction: sodium valproate, levetiracetam, lamotrigine (no CYP3A4 induction).
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Haloperidol tablet (Ajanta Pharma USA Inc.) – Prescribing Information (2020)– ; DailyMed setid 31e33656-2f53-49e6-9816-261ea2e6961a
- AEMPS: Ficha técnica: Carbamazepina (nº registro 62621), sección 4.5 (2025)– AEMPS, CIMA, nº registro 62621, sección 4.5
- AEMPS: Ficha técnica: Haloperidol Esteve 2 mg/ml solución oral (nº registro 58355), secciones 4.4 y 4.5 (2020)– AEMPS, CIMA, nº registro 58355, revisión 07/2020, secciones 4.4 y 4.5