ModerateMacrolides×SNRI (serotonin-norepinephrine reuptake inhibitor)
Updated · Methodology
Mechanism
Additive QT prolongation (venlafaxine prolongs QT at doses above 150 mg).
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 venlafaxine ≤150 mg, the combination is acceptable. At higher venlafaxine doses or cardiovascular disease: ECG before start or alternative antibiotics.
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: Effexor XR (venlafaxine) prescribing information (2017)– ; DailyMed setid c848a5d8-ba94-4c84-80e3-0bf35fb8e32e