History of β-lactam hypersensitivity, sensitivity to multiple allergens, or previous lgE-mediated reactions eg, anaphylaxis, angioedema, urticaria. Asthmatic patients. Risk of cross-allergy w/ cephalosporins; diarrhea, hepatic effects. Prolonged use may result to fungal/bacterial superinfections including C. difficile
-associated diarrhea & pseudomembranous colitis. Rash development during therapy in patients w/ infectious mononucleosis. Hepatic & renal impairment. Avoid use during pregnancy. Lactation. Childn ≤12 yr.