MajorFirst-generation antipsychotics. Butyrophenone derivatives×Systemic antimycotics. Imidazole derivatives
Updated · Methodology
Mechanism
Ketoconazole is a potent CYP3A4 inhibitor – the main haloperidol metabolic route. Haloperidol plasma levels rise 2- to 3-fold. Ketoconazole itself prolongs QT; effects add up.
Symptoms
QT prolongation on ECG. Dizziness, syncope, palpitations. Severe cases: polymorphic ventricular tachycardia (torsades de pointes). Risk is higher with hypokalaemia and hypomagnesaemia.
Management
Avoid the combination. Alternative antifungals: terbinafine or echinocandins. Alternative antipsychotics: olanzapine or aripiprazole.
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: 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