Keflex

Before taking this medicine

Do not take Keflex (cephalexin) if you have a known allergy to cephalexin or any other cephalosporin antibiotic. Tell your prescriber about previous allergic reactions to penicillins or other medicines, as cross-allergic reactions can occur. Extra caution and monitoring may be needed if you have reduced kidney function, particularly if it is severely reduced. Kidney impairment can increase the risk of toxic effects and seizures. Older adults may need particular care because reduced kidney function is more common with age. Tell your prescriber if you have liver disease, poor nutrition or take anticoagulants (blood thinners). These factors, along with prolonged antibiotic treatment, can increase the risk of delayed blood clotting. During pregnancy, cephalexin should be used only if clearly needed, as adequate studies in pregnant women are lacking. It passes into breast milk, so caution is needed when breastfeeding. Stop taking cephalexin and seek urgent medical help if an allergic reaction or seizure occurs. Serious allergic reactions, including severe skin reactions, have been reported. Diarrhea during treatment or even more than two months afterward may indicate a serious bowel infection and needs medical assessment. Anemia developing during or after treatment also needs assessment, as cephalexin can cause red blood cells to break down. Cephalexin should be used only for a proven or strongly suspected bacterial infection. Prolonged use may allow resistant organisms to grow and cause a new infection.