Is it safe to take azithromycin while taking effexor (venlafaxine) xr and quetiapine?

Drug interactions: Azithromycin can interact with both of those medications, creating an increased likelihood of a cardiac arrhythmia, or an irregular heartbeat (Called a "prolonged QR interval"). I would not take it until you have had a discussion with your physician about that possibility. Perhaps a different antibiotic may be more appropriate? Be cautious!