Penicillin Allergy & Allergy to other Beta-lactam Antibiotics

Penicillin Allergy – categories and definitions

The label of penicillin allergy is often incorrect. It will result in many life-saving antibiotics being ruled-out as options available for therapy.

When recording a 'penicillin-allergy' on the drug chart or in the patient medical records try wherever possible to clarify the nature of the allergy in as much detail as possible. Penicillin associated with diarrhoea for example is NOT allergy. This may necessitate discussion with family and friends, GPs or other healthcare professional who have been involved in previous episodes of medical treatment. 

 

SEVERE PENICILLIN ALLERGY:

(Type 1 immediate IgE mediated reactions)

 

Severe life-threatening adverse reactions due to immediate hypersensitivity are very uncommon.

Timing of onset: Normally within 1 hour of administration but can be up to 12 hours

Characteristic clinical signs:

  • Anaphylaxis
  • Angioedema
  • Urticarial rash/pruritus
  • Wheezing/stridor

 

NON-SEVERE PENICILLIN ALLERGY :

(Types II-IV and idiosyncratic reactions)

 

Timing of onset: more than 24 hours from administration of antibiotic

Characteristic clinical signs:

  • Maculopapular/morbilliform rash
  • Serum sickness (fever, rash, arthralgia, glomerulonephritis)

 

Useful information:

  • True IgE mediated Penicillin allergy is very rare (only 1 in 100 so labelled have genuine allergy)
  • Where true allergy is suspected and alternative antibiotics are severely limited consider referral to immunology for evaluation after discussion with microbiology.

http://www.worldallergy.org/

 

Individuals with Severe Penicillin Allergy (see above) SHOULD NOT receive a penicillin, cephalosporin or another beta-lactam antibiotic.

Individuals with Non-Severe Penicillin Allergy (see above) SHOULD NOT receive a penicillin but cephalosporins, carbepenems and other beta-lactams can be used for these patients with caution as the risk of cross sensitivity is low.

 

 Antibiotics

Penicillin Antibiotics

Amoxicillin

 (Amoxil®)

Benzylpenicillin

 (Crystapen®)

Co-amoxiclav

 (Amoxicillin/Clavulanic acid = Augmentin®)

Flucloxacillin

 (Floxapen®)

Co-fluampicil

 (Flucloxacillin/Ampicillin = Magnapen®)

Piperacillin/Tazobactam

 (Tazocin®)

Phenoxymethylpenicillin

(Penicillin V)

Temocillin 

(Negaban®)

Ticarcillin/Clavulanic acid

 (Timentin®)

 

Other beta-lactam antibiotics

Cephalosporins

 (e.g. Cefuroxime, Ceftriaxone, Cefradine)

Ertapenem

 (Ivanz®)

Imipenem/Cilastatin

 (Primaxin®)

Meropenem

(Meronem®)

Aztreonam

 (Azactam®) - may be used with caution in severe penicillin allergy: discuss with microbiology

 

 

Documentation and clarification of penicillin allergy

  • Ask your patient about their allergy - which drug & what happened?
  • Document the allergy - on drug chart and in medical notes

Refer to GHNHSFT antibiotics guidelines - for alternatives

 

Contact numbers

Microbiology CGH 4430, GRH 5050

Pharmacy Medicines Information CGH 3030, GRH 6108

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