MajorAntifungals, triazole derivatives×First-generation antipsychotics. Butyrophenone derivatives
Updated · Methodology
Mechanism
Dual mechanism. Fluconazole prolongs QT and blocks CYP3A4 and CYP2D6 – haloperidol metabolic routes. Haloperidol plasma levels rise; 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 with minimal QT effect: 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