Oral amoxicillin safe and effective in pregnant women allergic to penicillin, study finds

Canada: Pregnant women, having a history of penicillin allergy were able to successfully complete direct oral amoxicillin challenges without the need for prior skin testing, says an article published in The Journal of Allergy and Clinical Immunology: In Practice.

In various patient populations, penicillin allergy de-labeling has been found to be safe and successful in low-risk individuals. Testing demonstrates that more than 90% of people are not allergic in the first place. Despite the fact that pregnancy does not increase the risk of penicillin allergy, pregnant women are frequently omitted from most research. This study was conducted by Raymond Mak and team on the safety of Amoxicillin in pregnant women.

Between July 2019 and September 2021, clinicians at the BC Women's Hospital and Health Center gave direct oral challenges to 207 pregnant women between the ages of 28 and 36 weeks of pregnancy. Because these ladies all had a PEN-FAST score of 0, a proven, point-of-care penicillin allergy medical decision tool that anticipates the likelihood of positive skin tests, they were all judged extremely low risk. These ladies were observed for one hour after taking 500 mg of amoxicillin orally. Clinicians took their vital signs at the start, 15 minutes later, and an hour afterwards. Patients who showed no symptoms of IgE-mediated responses were dismissed with instructions to contact the clinic if they were concerned about a delayed reaction.

The key findings of this study were as follow:

1. There was no immediate or delayed hypersensitivity in 203 of these individuals.

2. The remaining four patients (1.93%) had benign maculopapular rashes, which were treated with betamethasone valerate 0.1% ointment and antihistamines.

3. The 1.93% response rate was comparable to a previously reported 1.99% rate in a non-pregnant adult population and a 2.5% rate in a pregnant population.

4. There were no people who required epinephrine or suffered anaphylaxis, and none were admitted to the hospital as a result of the testing.

In conclusion, according to the researchers, reducing the requirement for penicillin skin testing would cut reagent costs, clinic time, and the need to visit a subspecialist, all of which would enhance patient care during labor and delivery. For more strong proof, further large-scale investigations are required.

Reference:

Mak, R., Zhang, B. Y., Paquette, V., Erdle, S. C., Van Schalkwyk, J. E., Wong, T., Watt, M., & Elwood, C. (2022). Safety of Direct Oral Challenge to Amoxicillin in Pregnant Patients at a Canadian Tertiary Hospital. In The Journal of Allergy and Clinical Immunology: In Practice. Elsevier BV. https://doi.org/10.1016/j.jaip.2022.03.025