Moderate
Escitalopram × Ketoconazole
Selective serotonin reuptake inhibitors (SSRIs)×Systemic antimycotics. Imidazole derivatives
Mechanism
Escitalopram is metabolised mainly by CYP2C19 and partly by CYP3A4. Ketoconazole is a strong CYP3A4 inhibitor; escitalopram AUC rises modestly (20–40%) without major clinical effect. Additive QT risk is moderate.
Symptoms
QT prolongation on ECG. Dizziness, syncope, palpitations. Rarely: polymorphic ventricular tachycardia (torsades de pointes). Risk is higher with hypokalaemia, hypomagnesaemia, bradycardia, and ischaemic heart disease. Typical escitalopram side effects may appear: nausea, insomnia, decreased libido.
Management
For short systemic ketoconazole courses (7–14 days), cap escitalopram at 10 mg/day. Topical ketoconazole (shampoo, cream) does not interact. For long-term systemic therapy (e.g. invasive mycosis), antidepressant alternative: sertraline (minimal CYP3A4 interaction).