Moderate
Azithromycin × Escitalopram
Macrolides×Selective serotonin reuptake inhibitors (SSRIs)
Mechanism
Both prolong QT. Escitalopram dose-dependently (FDA Lexapro caps at 20 mg/day), azithromycin dose-dependently (FDA warning 2013).
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.
Management
For short azithromycin courses (3–5 days) with normal potassium and magnesium, the combination is acceptable. In atrial fibrillation, hypokalaemia, or prior QT prolongation: alternative antibiotics (doxycycline, a cephalosporin).
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.