Moderate
Azithromycin × Tramadol
Macrolides×Other opioids
Mechanism
Additive QT prolongation (tramadol weakly prolongs QT). Weak serotonergic risk (tramadol inhibits serotonin reuptake).
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) in patients without cardiovascular disease, the combination is acceptable. In epilepsy: watch tramadol-related seizure threshold reduction. Alternative analgesic: paracetamol or morphine/oxycodone (no QT effect).