Keflex, or cephalexin, belongs to a family of drugs called cephalosporins used to treat bacterial infections. Before you take any new medication, talk to your doctor or pharmacist about possible interactions. While Keflex reacts with a number of other drugs, it does not interact with foods, so you can eat a normal diet while taking the antibiotic.
A side-effect of Keflex is diarrhea, so avoid foods that will make runny stools worse, such as coffee, greasy or processed foods, dairy products and vegetables associated with flatulence such as broccoli, cabbage and peppers. Keflex may cause upset stomach in some people, which may be remedied by taking it with food or milk.
Some antibiotics, including metronidazole and tinidazole, will make you very sick if combined with alcohol. It is always a good idea to check with a pharmacist before drinking alcohol with any medication.