Azithromycin - Zpack
has a half-life of 4 days -which is why the 'Z-pack' is only 5 days long as compared to a standard course of antibiotics that may last 10 days.
If you were sick enough to require a Z-pack, then your health probably isn't 100% and therefore a doctor can't recommend a night of drinking and partying. Do what's right for you! I would recommend to take it easy. There will be other parties!