Cephalexin comes as a capsule, tablet, and suspension (liquid) to take by mouth. It is usually taken with or without food every 6 or 12 hours for 7 to 14 days, depending on the condition being treated. Cephalexin (Keflex, Keftabs) is an an antibiotic used to treat bacterial infections of the sinuses, tooth, urinary tract, and throat. Common side effects of Keflex include diarrhea, nausea, abdominal pain, headaches, and vaginitis. Dosage of cephalexin depends on the type of infection. Cephalexin, an antibiotic in the cephalosporin family, is used to treat infections caused by bacteria. Cephalexin is prescribed to treat respiratory tract, middle ear, skin, bone, and urinary. KEFLEX® (cephalexin) Capsules. DESCRIPTION. KEFLEX® (cephalexin) Capsules, USP is a semisynthetic cephalosporin antibacterial drug intended for oral administration. Cefalexin, also spelled cephalexin, is an antibiotic that can treat a number of bacterial infections. It kills gram-positive and some gram-negative bacteria by disrupting the growth of the bacterial cell wall. Cefalexin is a beta-lactam antibiotic within the class of first-generation cephalosporins. It works similarly to other agents within. Most cephalexin side effects are minor and can be easily treated by your healthcare provider. Common side effects experienced by adults and children include upset stomach, headache, and dizziness. Most of the time when there is a vaginal infection, they rx a medicated vaginal gel called metrogel for it. I think it might depend on which infection you have. Yes, cephalexin should help to treat strep throat. How long has she been on it? It may take a bit of time to resolve. If she still has symptoms after the course of antibiotic is finished then please see the doctor. WARNING: Use any drug with caution and realize that a small percentage of dogs can be allergic to any one of the following antibiotics. Cephalexin is typically used to treat bacterial infections and prevent heart valve infections. Bacterial infections that cephalexin can treat are sinus infections, irritations of the prostate, and skin infections (like cellulitis).