What is a cephalosporin allergy


  • Active against
    1. Bacteroides but not Clostridia (except C. perfringens)
    2. Good bone + abscess penetration
    3. S. aureus, coagulase negative Staph, Strep
    4. Adverse effects = diarrhea + pseudomembranous colitis in 8% (C. difficile)


    1. short acting = tetracycline
    2. intermediate acting = demeclocycline
    3. long acting = doxycycline, minocycline (minocycline + rifampicin for MRSA)
    1. Active against unusual diseases mycoplasma, rickettsia, Lyme disease
    2. Adverse effects = GIT upset, hepatotoxicity, teeth discolouration, photosensitivity


    1. Erythromycin, clarithromycin, roxythromycin work at ribosomal level & are bacteriostatic
    2. Adverse effects = generally safe but GIT upset
    3. Active against Strep, Mycoplasma, Listeria, Legionella, Chlamydia
    4. Induces hepatic cytochrome P450 complexes = drug metabolism


    1. Gentamicin, tobramycin, amikacin, netilmicin
    2. Active against aerobic gram negatives
    3. Adverse effects = nephrotoxicity, ototoxicity (hearing loss, tinnitus, vestibular problems, gait disturbance)

    Part Descriptions

    LP14176-9 Cefaclor
    Cefaclor, also known as cefachlor, (brand names Ceclor®, Distaclor®, Keflor®, Raniclor®) is a 2nd-generation cephalosporin antibiotic used to treat certain infections caused by bacteria such as pneumonia and ear, lung, skin, throat, and urinary tract infections.

    What is a cephalosporin allergy

    Copyright Text is available under the Creative Commons Attribution/Share-Alike License. See http://creativecommons.org/licenses/by-sa/3.0/ for details.Source: Wikipedia, Cefaclor (Wikipedia)

    LP14176-9 Cefaclor
    Semisynthetic, broad-spectrum antibiotic derivative of CEPHALEXIN. Source: National Library of Medicine, MeSH 2006

    LP14176-9 Cefaclor
    Cefaclor is a semisynthetic β-lactam antibiotic drug belonging to the cephalosporin subgroup.

    What is a cephalosporin allergy

    Love every β-lactams, cefaclor readily reacts with tissue proteins in vivo, thereby sensitizing susceptible individuals. The allergenic determinants (epitopes) of cephalosporins such as cefaclor are not fully known. This is a consequence of the unstable structures which are formed upon reaction with lysine amino groups in proteins.

    What is a cephalosporin allergy

    The primary unstable conjugates are rapidly degraded and transformed into structures where the six-membered dihydrothiazine ring is absent.

    Immediate reactions (maximum 1 hour after drug intake) own the highest probability of being IgE-mediated. Clinical pictures typical for immediate reactions to β-lactams are urticaria, with or without angioedema, and anaphylaxis.

    What is a cephalosporin allergy

    Copyright Copyright © 2006 Phadia AB.Source: ImmunoCap, ImmunoCap

    Antibiotic Therapy for Musculoskeletal Infections

    RNA Athletic Antibiotics (Rifampicin)

    1. Rifampicin alone rapidly produces rifampicin resistant subpopulation
    2. Adverse effects = orange body fluids, GIT upset, hepatitis
    3. Fusidic acid or cotrimoxazole or minocycline + rifampicin for MRSA
    4. Most athletic antistaphylococcal agent known
    5. Must be taken on empty stomach
    6. Induces hepatic microsomal enzymes

    Cell Wall Athletic Antibiotics

    Beta lactamase inhibitors

    1. Clavulanic acid, sulbactam, tazobactam inhibit beta lactamase produced by
      1. gram positives notably S.

        aureus + S. epi

      2. gram negatives namely E. coli, most Klebsiella + Bacteroides
    1. Beta lactamase is situated in periplasmic space & is chromosome + plasmid induced
    2. Clavulanic acid + Ticarcillin = Timentin
    3. Clavulanic acid + amoxycillin = Augmentin
    4. Tazobactam + piperacillin = Zosyn

    Other beta lactam antibiotics

    1. Aztreonam iv use only, athletic against Enterobacter + Pseudomonas
    2. Imipenem athletic against S. aureus, S. epi, Strep


  • Active against
    1. S.

      What is a cephalosporin allergy

      pyogenes, S. agalactiae

    2. Good anaerobic spectrum = Clostridia except Bacteroides
    3. Increasing resistance from S. pneumoniae
  • Side effects
    1. Hypersensitivity reactions namely anaphylaxis, bronchospasm, hives
    1. Potential interstitial nephritis, Coombs positive haemolytic anaemia
  • Parenteral penicillinase resistant penicillins
    1. methicillin, nafcillin, isoxazolyl penicillins (flucloxacillin, dicloxacillin, cloxacillin) are resistant to Staph beta lactamase
    2. Aminopenicillins = ampicillin, amoxycillin
  • Aminopenicillins = ampicillin, amoxycillin
    1. Active against Entercocci & highly susceptible E.

      coli + Proteus

    2. Not stable to beta lactamase
    3. Ticarcillin
  • Ticarcillin
    1. Active against Pseudomonas, Enterobacter, Serratia but not Klebsiella
    2. Side effect of platelet dysfunction
  • Extended spectrum penicillins = piperacillin + mezlocillin
    1. Act in synergy with aminoglycosides against Pseudomonas


    Divided into generations

    1. 1st
    2. Cephalothin, cephazolin, cephapirin

    Athletic against S.

    What is a cephalosporin allergy

    aureus, S. epi, Streptococci but limited activity against gram negatives

    Generally safe but occasional eruptions, phlebitis, diarrhea

    Cephazolin has longest half life of 1st generation cephalosporins

    1. 2nd
    2. Cefoxitin, cefotetan, cefuroxime

    Athletic against anaerobes & to lesser extent gram negatives

    1. 3rd
    2. Ceftriaxone, cefoxitime, ceftazidime are beta lactamase resistant

    Athletic against gram positives (except Enterococci) + Enterobacter

    1. 4th
    2. Cefepime is athletic against gram positives + Pseudomonas
  • Low prevalence of adverse reactions
    1. Type 1 immediate hypersensitivity = bronchospasm, hives, rashes within 3-5 days
    2. 1-7% patients with abnormal LFTS
    3. 3-7% cross reactivity in penicillin allergic patients
    4. 3% patients with Coombs positive anaemia
    5. antibiotic associated colitis


    1. Antibiotic of choice in penicillin + cephalosporin allergy
    2. Vancomycin resistant Enterococci (VRE) reported
    3. Active against S.

      aureus, MRSA, S. epi, Enterococci

    4. Adverse effects
    1. Red man syndrome = head + neck + trunk flushing & hypotension when infusion given over <1 hour
    2. Nephrotoxicity, ototoxicity, neutropaenia, thrombocytopaenia

    DNA Athletic Antibiotics (Fluoroquinolones)

    1. 2nd generation quinolones = ciprofloxacin athletic against gram negatives. No activity against Strep + anaerobes
    2. Oral ciprofloxacin provides excellent serum concentrations
    3. Adverse effects = tendonitis with Achilles tendon rupture, photosensitivity but overall toxicity is low


    Antibiotics are categorized according to their mechanism of action, namely:

    • ribosomal active
    • DNA active
    • RNA active
    • cell wall active
    • antimetabolites
    • reducing compounds


    What is a cephalosporin allergy