Is it safe to mix Flagyl and alcohol? Reviewed By Jessica Caporuscio, PharmD and Alan Carter, PharmD Drinking alcohol while taking Flagyl can cause serious side effects. Doctors and pharmacists advise people to avoid alcohol entirely while using the medication in any form, including oral Flagyl tablets and topical Flagyl creams. Flagyl is an antibiotic that treats many infections, including abdominal and sexually transmitted infections (STIs). While not all antibiotics interact with alcohol, drinking while using certain types — including Flagyl — can have serious health consequences. People should generally avoid alcohol for up to 3 days after the last dose of Flagyl. In this article, we look at what Flagyl is and the risks of mixing it with alcohol. We also describe when it is safe to drink alcohol again. What is Flagyl? A doctor may prescribe Flagyl to treat various infections. Flagyl is the brand name of the antibiotic metronidazole. Metronidazole is part of ...