Antibiotics and alcohol can cause some of the same side effects. These include stomach upset, dizziness and drowsiness. Mixing antibiotics and alcohol can make these side effects worse.

A few antibiotics should not be mixed with any amount of alcohol. These include metronidazole (Flagyl), tinidazole (Tindamax) and sulfamethoxazole-trimethoprim (Bactrim, Septra). Drinking alcohol with these medicines can cause side effects such as flushing, headache, nausea and vomiting, and fast heart rate.

Also, the antibiotic linezolid (Zyvox) interacts with some alcoholic drinks, including red wine and tap beer. Drinking these with this medicine can cause a harmful rise in blood pressure.

Keep in mind that some cold medicines and mouthwashes also have alcohol. So check the label. Don't use such products while taking these antibiotics.

Modest alcohol use doesn't affect most antibiotics. But drinking alcohol can lower your energy and slow how fast you get better from illness. So it's a good idea not to drink alcohol until you finish your antibiotics and are feeling better.