There are two types of antibiotics that are commonly prescribed that can cause painful and unsightly skin rashes that can lead to life-threatening sepsis if left untreated.
Complications from the pills, which are given to treat a range of common infections including urinary tract infections and pneumonia, can lead to death in 20 to 40 percent of cases, according to a new 20-year study.
In an article published in the journal JAMA Network, the experts responsible for the research urged doctors to use lower-risk alternatives.
For the study, doctors at Sunnybrook Health Sciences Centre in Canada looked at more than 100,000 patients over the age of 66 who were prescribed oral antibiotics and studied the drugs’ harmful effects.
Drug-induced skin rashes, also known as severe cutaneous adverse drug reactions (cADRs), are rare but potentially life-threatening delayed reactions to certain medications.
Over the 20-year study period, they found that 20 percent of the patient group visited the hospital for severe skin rashes, also known as cutaneous adverse drug reactions (cADRs).
Rashes can appear immediately after taking a medication, or weeks later, and are often caused by an allergic reaction.
Symptoms usually affect the skin, causing red, scaly patches all over the body, but can trigger a dangerous overreaction of the immune system if left untreated.
Rarely, this leads to sepsis, where the immune system attacks itself, causing multiple organ failure and sometimes death.
Canadian researchers found that the antibiotics most likely to cause this reaction were cephalosporins and sulfonamides (or “sulfa”) drugs.
In addition to penicillin, cephalosporins such as cephalexin are among the most commonly prescribed antibiotics and are used to treat pneumonia, meningitis, sepsis, and urinary tract infections.
The antibiotic is also often given to children allergic to penicillin to treat ear infections.
Sulfonamide drugs, including trimethoprim, are used to treat urinary tract infections, as well as inflammatory bowel disease, malaria, and various skin, eye, and vaginal infections.
Dr Dean Eggitt, a GP in Doncaster, says GPs offer both types of antibiotics for a range of infections, although sulphonamide drugs are more commonly prescribed.
“They are known to be very effective and cheap,” she told MailOnline. “However, cephalosporins are prescribed much less than before because many people have developed resistance to them.”
David Juurlink, MD, an internist and chief of the Division of Clinical Pharmacology and Toxicology at Sunnybrook Health Sciences Centre, added: “While rare, these severe drug reactions can be life-threatening,” he said.
‘Patients should be alert for rash, fever and other symptoms, which may begin weeks after starting a medication and even after finishing antibiotic treatment.
“It is also one more reason why antibiotics should be prescribed only when really necessary.”
All antibiotics can cause rashes, as can anti-seizure and anti-gout medications and even over-the-counter medications like NSAIDs.
And although some patients have severe reactions, most drug rashes are treatable.
“The good news is that most patients who visited the hospital with these reactions were discharged without being admitted, so this should be reassuring to providers and patients,” says Erika Lee, an allergist and fellow at ICES and the Eliot Phillipson Clinical Scientist Training Program at Temerty Medicine.
‘However, of those who were admitted to hospital with the most severe reactions, twenty percent were treated in ICU and five percent of hospitalized patients died, underscoring the need for careful prescribing practices.’
