Do not use this medication if you are allergic to cephalexin, or to similar antibiotics, such as Ceclor, Ceftin, Cefzil, Duricef, Fortaz, Omnicef, Spectracef, Suprax, and others.
Before using cephalexin, tell your doctor if you are allergic to any drugs (especially penicillins), or if you have kidney or liver disease, a stomach or intestinal disorder such as colitis, diabetes, or if you are malnourished.
Take this medication for the entire length of time prescribed by your doctor. Your symptoms may get better before the infection is completely treated. Cephalexin will not treat a viral infection such as the common cold or flu.