Wescom News Service

One out of 5 patients who received antibiotics while in the hospital experienced an adverse side effect, according to a new study from researchers at The Johns Hopkins Hospital. Moreover, the study showed that nearly a fifth of those patients didn’t actually need antibiotics.

By the numbers — Doctors at Hopkins examined the medical records of 1,488 adults admitted to the hospital over a 10-month period and who received at least 24 hours of antibiotic treatment.

They found that, overall, 20 percent of patients on antibiotics experienced one or more side effects within 30 days, generally gastrointestinal, kidney or blood abnormalities.

For every additional 10 days of antibiotic use, the risk of a side effect went up 3 percent. Some 4 percent of the patients developed a Clostridium difficile infection and 6 percent incurred multi-drug resistant infections within 90 days.

“Too often, clinicians prescribe antibiotics even if they have a low suspicion for a bacterial infection, thinking that even if antibiotics are not benign, they are probably not harmful,” said Dr. Pranita Tamma, assistant professor of pediatrics at the hospital and the lead author of the study. “But that is not always the case. Antibiotics have the potential to cause real harm to patients.”

One in 4 patients had to have extended hospital stays due to their side effects, 9 percent had additional emergency room or clinic visits and 3 percent had to be readmitted to the hospital.

When infectious disease specialists reviewed the records, they found that 19 percent of patients had no indication of bacterial infections and should not have been prescribed antibiotics at all.

Bottom line — The study, published in the journal JAMA Internal Medicine, has a number of limitations. It was conducted at a single site, an academic hospital with a complex set of patients, and so may not be applicable to other settings. Hopkins also has ongoing efforts to improve antibiotic prescribing by its doctors, which have affected the results. Antibiotics remain a vital tool in fighting off bacterial infections when used appropriately. But doctors say they often feel pressured by patients to prescribe antibiotics even when they are not necessary. The study suggests that may have more consequences than previously realized.