Penicillin allergy is rarer than thought: pharmacists’ report

Pharmacists warn that nine out of 10 patients who believe they’re allergic are not, and the result is prolonged recovery periods.

Penicillin can be used to treat many types of infection. Picture: PA/The Times

Nine out of 10 people who believe they are allergic to penicillin are not, pharmacists have said.

People incorrectly thought to be allergic may be harmed, they warned, receiving less effective drugs that mean prolonged recovery periods or treatment in hospital.

The Royal Pharmaceutical Society (RPS) suggested that patients should check their medical record the next time they visited their GP to ensure they were not wrongly recorded as allergic. Penicillin is an antibiotic used to treat many types of infection.

A paper in the British Journal of Clinical Pharmacology in 2019 suggested that between 6 per cent and 10 per cent of the population in the UK and United States are recorded as allergic to penicillin, “although emergent research shows that 90-95 per cent of these labels are found to be incorrect following comprehensive allergy testing”.

Research published in the Journal of Antimicrobial Chemotherapy in 2019 estimated that incorrect penicillin allergy records affected 2.7 million people in England alone.

The RPS said that people might believe they were allergic because they had suffered common side-effects, such as nausea or diarrhoea.

Those who are recorded as allergic to penicillin may be treated with less effective drugs. Picture: LWA/Getty Images/The Times

Sometimes, the infection being treated may also cause a rash that may be seen as an allergic reaction and recorded as such. In addition, the allergy may remain in records years from years earlier, but may in fact have been outgrown.

Data suggests those with penicillin allergy records have an increased risk of death after treatment, compared with other patients. In the year after treatment for infections in those thought to be allergic there were six deaths per 1000 patients.

“Every medicine has benefits and harms and I urge patients to ask questions about a penicillin allergy label on their medical record,” RPS spokeswoman Tase Oputu said.

“Many individuals are at low or very low risk of having a genuine penicillin allergy and we often find that after careful investigation that they can take penicillin safely. Others, who may have had a severe reaction in the past, will need allergy testing and in some cases may never be able to take penicillin.”

The NHS and global health organisations are trying to reduce the use of antibiotics because of increasing antibiotic resistance, in which strains of bacteria no longer respond to the drugs.

The NHS website says many infections are caused by viruses, for which antibiotics are not effective, and that antibiotics are often unlikely to speed up the healing process and can cause side-effects.

It adds that antibiotics are no longer routinely used to treat chest infections, ear infections in children or sore throats.

The Times