Cipro, generic name ciprofloxacin, and Keflex, generic name cephalexin, are antibiotics that belong to different drug classes. Cipro is a type of fluoroquinolone and Keflex is a type of penicillin. Cipro and Keflex can cause similar side effects like abdominal pain, diarrhea, nausea, vomiting, headache, and skin rashes.

Keflex has fewer serious side effects than Cipro, for example, anaphylaxis, a type of severe allergic reaction. Cipro and Keflex both can cause a serious infection with C. difficile, which causes severe, chronic diarrhea and may lead to pseudomembranous colitis. Cipro has many serious side effects, for example, Achilles tendon rupture, peripheral nerve pain, CNS problems, high blood sugar, abnormal heart rhythms, hepatitis, yellowing of the skin and eyes (jaundice), liver failure, acute kidney failure, cardiac arrest, and respiratory failure.

Cipro and Keflex are used to treat bacterial infections, for example, infections of the ears, skin, bone, urinary tract, and C. difficile (infectious diarrhea). Cipro also is used for the treatment of lower respiratory infections, sinusitis, chronic prostatitis, TB, typhoid fever, cystitis, the plague, anthrax poisoning, and bronchiectasis. Keflex also is used for the treatment of infections of the middle ear, tonsils (tonsillitis), bronchioles (bronchitis), laryngitis (larynx), and lungs (pneumonia).