Allergies

Penicillin Allergy

Ten per cent of patients who are allergic to penicillin will also be allergic to cephalosporins. If the allergic reaction to penicillin is non-severe e.g. minor rash or delayed rash (>72 hours after administration), cephalosporins or meropenem can be given. If the allergic reaction is severe e.g. anaphylaxis, urticaria, or rash immediately after penicillin administration, cephalosporins and meropenem must be avoided.

Note that co-amoxiclav (Augmentin®) and piperacillin-tazobactam (Tazocin®) are penicillin-based.

Approximately 10% of patients allergic to penicillin will also be allergic to The guidelines do not cover every eventuality. Advice on antibiotic therapy can be meropenem. If the patient has a history of anaphylactic reaction to penicillin, but no alternative antibiotics are available, meropenem can be used with caution (patient under careful observation with team ready to treat anaphylaxis, should it occur). If an allergic reaction to meropenem occurs, the drug should be discontinued and an alternative discussed with microbiology. Click here for a summary penicillin/beta-lactam allergy chart.

Agents contraindicated in non-severe or severe penicillin allergy (this is not an exhaustive list):

  • Amoxicillin
  • Benzathine penicillin
  • Benzylpenicillin (penicillin G)
  • Co-amoxiclav (Augmentin®)
  • Flucloxacillin
  • Phenoxymethylpenicillin (penicillin V)
  • Pivmecillinam
  • Piperacillin and tazobactam (Tazocin®)
  • Temocillin
  • Ticarcillin and clavulanic acid (Timentin®)

Agents that can be used with caution in patients with non-severe penicillin allergy (i.e. do not use if history of anaphylaxis, urticaria, or rash immediately after penicillin administration, unless discussed with Microbiology, in the event there are no alternative agents):

  • Aztreonam
  • CefaCLOR
  • CefaLEXin
  • CefOTAXime
  • CefTAZidime
  • CefTRIAXone
  • CefUROXime
  • Ertapenem
  • Imipenem
  • Meropenem

Agents that can be used safely in patients with non-severe or severe penicillin allergy:

  • Amikacin
  • Azithromycin
  • Chloramphenicol
  • Colistin
  • Co-trimoxazole
  • Erythromycin/clarithromycin
  • Ciprofloxacin
  • Clindamycin
  • Daptomycin
  • Doxycycline
  • Fidaxomicin
  • Fosfomycin
  • Gentamicin
  • Linezolid
  • Metronidazole
  • Moxifloxacin
  • Nitrofurantoin
  • Ofloxacin
  • Rifampicin
  • Sodium fusidate
  • Teicoplanin
  • Tigecycline
  • Tobramycin
  • Trimethoprim
  • Vancomycin