Cephalexin is a cephalosporin (SEF a low spor in) antibiotic. It works by fighting bacteria in your body. Cephalexin is used to treat infections caused by bacteria, including upper respiratory infections, ear infections, skin infections, urinary tract infections and bone infections. Find patient medical information for Cephalexin (Keflet, Keflex, Keftab) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings To reduce the development of drug-resistant bacteria and maintain the effectiveness of cephalexin and other antibacterial drugs, cephalexin capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. Cephalexin treats infections like strep throat, UTIs, and skin infections. Learn how it works, common dosages, and what side effects to watch out for. Cephalexin is used to treat bacterial infections in many different parts of the body (eg, bones, ears, lungs, skin, urinary tract). Cephalexin belongs to the group of medicines known as cephalosporin antibiotics. Easy-to-read patient tips for cephalexin covering how it works, benefits, risks, and best practices. Cephalexin 500 mg is considered a moderate-strength antibiotic that works well for many common bacterial infections. It belongs to the cephalosporin family and packs enough punch for most routine infections while causing fewer side effects than some stronger options.