Direct Oral Penicillin Challenge Noninferior to Standard of Care

TUESDAY, July 25, 2023 (HealthDay News) -- For patients with low-risk penicillin allergy, direct oral penicillin challenge is noninferior to standard-of-care skin testing followed by oral challenge, according to a study published online July 17 in JAMA Internal Medicine.

Ana Maria Copaescu, M.D., from the Centre for Antibiotic Allergy and Research at Austin Health in Heidelberg, Australia, and colleagues examined whether a direct oral penicillin challenge is noninferior to the standard-of-care penicillin skin testing followed by oral challenge in an international randomized clinical trial. A total of 377 patients with a low-risk penicillin allergy were randomly assigned to direct oral challenge with penicillin (intervention arm; 187 patients) or standard-of-care penicillin skin testing (190 patients).

Most of the patients had a PEN-FAST score of 0 or 1. The researchers found that the primary outcome of physician-verified positive immune-mediated oral penicillin challenge within one-hour postintervention occurred in 0.5 and 0.5 percent of patients in the intervention and control groups, respectively, with a risk difference of 0.0084 percentage points (90 percent confidence interval, −1.22 to 1.24 percentage points). The one-sided 95 percent confidence interval was below the noninferiority margin of 5 percentage points. Nine immune-mediated adverse events were recorded in the intervention group and 10 were recorded in the control group in the five days following the oral penicillin challenge (risk difference, −0.45 percentage points; 95 percent confidence interval, −4.87 to 3.96 percentage points). There were no serious adverse events reported.

"Compared with skin testing, a direct oral penicillin challenge is less resource and time intensive, is less expensive, and has the potential to be performed outside of the specialist allergy setting, providing a scalable approach to address low-risk, unverified penicillin allergy in diverse treatment settings internationally," the authors write.

Two authors disclosed ties to the biopharmaceutical and medical technology industries.

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