Erythromycin is rarely indicated for prophylaxis because of its relatively narrow spectrum and pharmacokinetic profile. Where there is history of allergy such as anaphylaxis or acute bronchospasm, Vancomycin or Teicoplanin should be used. If however, the history is somewhat vague then a cephalosporin may be substituted for ampicillin or penicillin as the risk of cross-allergy is only 10%