In 1945 Australian pharmacologist Howard Florey, together with physician Alexander Fleming and biochemist Ernst Chain, received the Nobel Prize for Physiology and Medicine for the development of the first broadly effective antibiotic, penicillin. The use of penicillin and related penicillin antibiotics is nowadays ubiquitous and has transformed clinical practice, but with its abundant use, patient-reported unwanted reactions to penicillins are also common. 

Learning objectives

After reading this article, pharmacists should be able to:

  • Explain penicillin allergy with respect to the most common immunological response
  • Discuss cross reactivity of cephalosporins in individuals allergic to penicillins
  • Discuss the impact of an incorrect attribution of an antibiotic allergy.

Competency standards (2016) addressed: 1.1, 1.4, 1.5, 1.6, 2.2, 2.4, 3.1, 3.2, 3.3

Already read the CPD in the journal? Scroll to the bottom to SUBMIT ANSWERS.

These adverse drug reactions (ADRs) can broadly be classified as Type A (predictable side effects based on known drug pharmacological properties, e.g. gastrointestinal side effects with certain antibiotics), or Type B (unpredictable “idiosyncratic” adverse reactions).1 Type B reactions that are immune mediated are termed drug allergies. ADRs that cannot entirely be explained by either mechanism are referred to as ‘intolerances’.2

In the last 75 years we have made significant progress in our understanding of the pathogenesis of drug allergies; however, this has not translated efficiently into the development of faster and

THIS IS A CPD ARTICLE. YOU NEED TO BE A PSA MEMBER AND LOGGED IN TO READ MORE.