Penicillin Allergy – categories and definitions

Individuals with a DEFINITE history of ANAPHYLAXIS or URTICARIAL RASH immediately after penicillin administration are at risk of immediate hypersensitivity to a penicillin. These individuals SHOULD NOT receive a penicillin, a cephalosporin or another beta-lactam antibiotic (e.g. meropenem).

 

Individuals with a DEFINITE history of NON-URTICARIAL RASH allergy to penicillin SHOULD NOT receive a penicillin but the likelihood of serious cross sensitivity with cephalosporins or carbapenems is very low, so other non-penicillin beta-lactam antibiotics can still be used in these individuals.

 

Individuals with a history of minor rash or a rash that occurs 72 hours after penicillin administration are PROBABLY NOT ALLERGIC TO PENICILLIN and in these individuals a penicillin should not be withheld unnecessarily for serious infection. The possibility of an allergic reaction should, however, be borne in mind*

*(BNF No.60.London. BMA & RPS March 2010).

 

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

Penicillin Antibiotics
Amoxicillin Benzylpenicillin Co-amoxiclav Flucloxacillin Co-fluampicil Piperacillin/Tazobactam Phenoxymethylpenicillin Ticarcillin/Clavulanic acid	(Amoxil®) (Crystapen®) (Amoxicillin/Clavulanic acid = Augmentin®) (Floxapen®) (Flucloxacillin/Ampicillin = Magnapen®) (Tazocin®) (Penicillin V) (Timentin®)

 

Other beta-lactam antibiotics
Other non-penicillin beta-lactam antibiotics may cause allergic reactions in up to 10% of patients with anaphylactic penicillin allergy. Because of this risk, non-penicillin beta-lactam antibiotics should NOT be prescribed in patients with known anaphylactic penicillin allergy. If their use is being considered in this context then this must be discussed with the consultant responsible for the patient before the first dose is administered.
Cephalosporins Ertapenem Imipenem/Cilastatin Meropenem	(e.g. Cefuroxime, Ceftriaxone, Cefradine) (Ivanz®) (Primaxin®) (Meronem®)

 

• Click here for Penicillin Allergy Poster

 

Further information can also be found in the BNF.

Refer to GHNHSFT antibiotics guidelines - for alternatives

 

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