Penicillin allergy increases risk for use of less-effective antibiotics

June 29 (UPI) -- People allergic to penicillin are nearly twice as likely to receive a less effective antibiotic during hospitalization, with more side effects, those who are not allergic to the drug, an analysis published Monday by JAMA Internal Medicine found.

In all, 16% of hospitalized patients have a penicillin allergy, with 45 percent of allergic reactions to the drug involving hives or rash, the researchers said.

Most of those allergic to the antibiotic, 64 percent, received a "broad-spectrum" beta-lactam -- a class of drugs that acts on a wide range of disease-causing bacteria, they found.

Use of broad-spectrum antibiotics has been linked with development of resistant bacteria, or those that don't respond to drug treatment.

"I suggest patients discuss their drug allergies with their primary care provider," co-author Dr. Kimberly Blumenthal, quality and safety officer for allergy at Massachusetts General Hospital, told UPI.

"It may be possible to clarify the allergies without testing, or testing -- such as penicillin skin testing -- may be recommended," she said.

Roughly half of all hospitalized patients receive an antibiotic, Blumenthal said. Historically, research has suggested that roughly one in 10 people have a penicillin allergy listed in their medical records.

However, testing "disproves" up to 90 percent of these cases, Blumenthal and her colleagues said.

For their study, the researchers reviewed data on nearly 11,000 patients from the Irving, Texas-based Acute Care Hospital Groups, which are part of Vizient Inc.

Among participants, 48 percent of patients without a penicillin allergy received a broad-spectrum beta-lactam antibiotic, they said. Just 13 percent of patients with a penicillin allergy received a narrow-spectrum -- or more targeted -- beta-lactam, compared to 30 percent of non-allergic patients, the researchers found.

Narrow-spectrum beta-lactams are less likely to cause resistance, they said.

In addition, those with a penicillin allergy were more than twice as likely to receive a broad-spectrum antibiotic to treat a urinary tract infection and more than seven times as likely to receive these drugs for infection prevention before surgery, the researchers said.

"Broader-spectrum [antibiotics are] associated with treatment failures and adverse reactions," Blumenthal said. "I would encourage patients with a penicillin allergy on their medical record to seek out confirmatory testing ... before being sick or hospitalized."