Major
citalopram × Fluconazole
SSRI (selective serotonin reuptake inhibitor)×Antifungals, triazole derivatives
Mechanism
Dual risk. Fluconazole blocks CYP2C19 (strongly) and CYP3A4 (moderately) and prolongs QT itself. Citalopram plasma levels rise, plus additive QT prolongation.
Symptoms
QT prolongation on ECG. Clinically: dizziness, syncope, palpitations. Severe cases progress to polymorphic ventricular tachycardia (torsades de pointes). Risk is higher with hypokalaemia, hypomagnesaemia, bradycardia, and ischaemic heart disease.
Management
Cap citalopram at 20 mg/day when combined. ECG before start and every 3 days during therapy. Alternative antifungals: echinocandins for systemic mycoses or terbinafine for dermatophytosis.
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.