According to the UK's National Health Service, there is no known interaction between the antibiotic azithromycin and alcohol. However, the Mayo Clinic recommends that patients discuss alcohol consumption with their doctors before taking any drug.
The Mayo Clinic provides a long list of medications that typically should not be mixed with azithromycin, such as erythromycin, methadone, quinine and warfarin. However, the combination of prescriptions is occasionally required. On-going medical conditions sometimes interfere with the function of azithromycin. These include cystic fibrosis, weakened immune system, hospital-acquired infections and congestive heart failure. In all patients, a common mild side effect is diarrhea.