Sulfonamide, cephalosporins linked with serious skin reactions in older patients
Relative to macrolides, sulfonamide and cephalosporins were each associated with a nearly threefold increased risk of serious cutaneous adverse drug reactions in adults older than age 66 years, a study of residents in Ontario, Canada, found.
Six classes of commonly prescribed oral antibiotics are linked with more serious cutaneous adverse drug reactions among older adults when compared with macrolides, with sulfonamide and cephalosporins carrying the highest risk, a population-based study found.
Researchers used administrative health databases to identify adults ages 66 years or older who received at least one oral antibiotic between 2002 and 2022 in Ontario, Canada. All serious cutaneous adverse drug reactions that resulted in an ED visit or hospitalization within 60 days of the prescription (n=21,758) were matched with up to four controls (n=87,025). Findings were published by JAMA on Aug. 8.
Sulfonamide antibiotics (adjusted odds ratio [aOR], 2.9; 95% CI, 2.7 to 3.1) and cephalosporins (aOR, 2.6; 95% CI, 2.5 to 2.8) carried the highest risk for serious reactions versus macrolides. Nitrofurantoin (aOR, 2.2; 95% CI, 2.1 to 2.4), penicillins (aOR, 1.4; 95% CI, 1.3 to 1.5), and fluoroquinolones (aOR, 1.3; 95% CI, 1.2 to 1.4) were all also associated with a heightened risk. Crude rates of ED visits or hospitalization for skin reactions were highest for cephalosporins (4.92 per 1,000 prescriptions; 95% CI, 4.86 to 4.99) and sulfonamide antibiotics (3.22 per 1,000 prescriptions; 95% CI, 3.15 to 3.28).
Overall, 2,952 patients were hospitalized for reactions, with a median length of stay of 6 days (interquartile ratio [IQR], 3 to 13 days). Of these, 9.6% required transfer to a critical care unit and 5.3% died in the hospital. Median time from antibiotic prescription to hospital visit for a reaction was 14 days (IQR, 7 to 35 days). Among cases and controls, penicillin was the most commonly prescribed antibiotic, followed by cephalosporins, fluoroquinolones, macrolides, nitrofurantoin, and sulfonamides, respectively.
“Roughly 2 hospital visits for cADRs [cutaneous adverse drug reactions] ensued for every 1,000 antibiotic prescriptions, but most did not lead to hospitalization,” the researchers wrote. The study is the first to the authors' knowledge to use population-based data to estimate the relative and absolute risks of these reactions following outpatient antibiotic therapy.
Limitations include that researchers were unable to account for genetic susceptibility to adverse reactions and could not evaluate the use of nonprescription medications. “Our results highlight the risk of serious cADRs following commonly prescribed antibiotics and underscore the importance of judicious prescribing, with preferential use of antibiotics associated with a lower risk when clinically appropriate,” the authors concluded.