Cephalosporins

72

Summary

Cephalosporins are a class of antibiotics that are used to treat a wide variety of bacterial infections. Cephalosporins are easy to recognize because they all start with “ceph-”, like ceftriaxone, cefazolin, and cephalexin. Cephalosporins can have a cross sensitivity with penicillins, so if a patient is allergic to one, the severity of the allergic reaction should be determined before giving the other. Patients taking cephalosporins should avoid alcohol to prevent a disulfiram-like reaction. Cephalosporins can cause bleeding so other drugs that cause bleeding should be avoided, like NSAIDs and anticoagulants.

Key Points

  • Cephalosporins
    • Key Drugs
      • Cef-, Ceph-
        • Ceftriaxone (Rocephin)
        • Cefazolin (Ancef)
        • Cephalexin (Keflex)
      • There are 5 different generations of cephalosporins and each generation has coverage for a slightly different spectrum of bacteria
    • Mechanism
      • Beta-lactam Antibiotic
        • Inhibits bacterial cell wall synthesis
    • Clinical Uses
      • Bacterial infections
        • Surgical infection prophylaxis against skin flora
        • Otitis media
        • Meningitis
        • Appendicitis
        • Urinary Tract Infections
        • Respiratory Infections
        • Etc.
    • Side Effects and Adverse Reactions
      • Cross-sensitivity with penicillins
        • The structure and function of cephalosporins is similar to that of penicillins (beta lactam antibiotics) so there can be cross sensitivity
        • Cross-allergenicity rates are relatively low (only about 1-4%)
        • If the patient has a penicillin allergy, the order for cephalosporins should be questioned.
      • Disulfiram-like reaction
        • Do not take with alcohol
      • Bleeding
        • Secondary to vitamin K deficiency, as cephalosporin prevents vitamin K activation which is required for the synthesis of blood clotting factors
        • Thrombocytopenia
        • Avoid drugs that may promote bleeding (e.g. NSAIDS, anticoagulants)
      • Clostridium Difficile overgrowth
        • Broad-spectrum antibiotics like cephalosporins can cause C. difficile overgrowth by killing existing gut flora to open a niche.
        • Cephalosporins cannot treat C. difficile infections
        • Severe diarrhea should be reported, as it may indicate a c. diff. infection
        • Other types of superinfection secondary to antibiotic use include yeast (Candida) infections.
      • GI Distress (nausea, vomiting, diarrhea, anorexia)
        • May be taken with food to reduce GI distress