Penicillins are the most common antibiotic class prescribed globally in primary, secondary and tertiary care for common and serious bacterial infections, including sepsis. They are cost-effective medications, available in parenteral and oral formulations and have an excellent safety profile. The downside to the use of penicillins is that they are most commonly implicated in adverse drug reactions including allergy or hypersensitivity, the latter owing to a greater chance of becoming sensitised following frequent exposure.