D1.217 - Rapid drug desensitization in children: case report

Background

If drug hypersensitivity is confirmed, the avoidance of the culprit drug and a suggestion of an unrelated alternative is enough. However, when no alternative or effective drug is available or in circumstances where the choice to stop the treatment affects the survival of patients, drug desensitization can be the best option.

Method: case reports

Results

Case 1:

A 9-day-old girl admitted to the Neonatal department with symptoms of congenital syphilis, TPHA evaluated positive (+++) PRP 8. As the standard treatment for syphilis in pregnancy, her mother had intramuscular injections of penicillin G.

The girl was treated with penicillin G 50,000 units/kg IV every 8 hours. Soon after the second dose of penicillin, within 1 hour, the child had urticaria as well as erythema in face, neck, and leg. After an assessment indicating that the benefits outweigh the risks, we recommended penicillin desensitization.

We use the intravenous penicillin desensitization protocol with sixteen steps. The interval between doses is 15 min, total time = 165 min. We observed the patient every 15 min and for 30 min after the final step, then gave full therapeutic dose (102 mg # 170,000 UI) by the desired route. After rapid desensitization, the baby received a full therapeutic dose for 14 days and experienced no breakthrough reactions.

Case 2:

A 10-day-old girl was admitted to the NICU department due to severe pneumoniae-sepsis. She was treated with ampicillin + cefotaxime + gentamycin. On the sixth day of treatment, about 5 minutes after the third dose of ampicillin she got pallor and floppiness as well as decreased peripheral capillary oxygen saturation. After two doses of intramuscular adrenaline, all symptoms significantly improved. Therefore, she was diagnosed with anaphylactic shock due to ampicillin. Because of severe infection, the alternative treatment with carbapenem was the best choice. However, cross-reactivity was really a principal issue, so we decided to perform meropenem desensitization as the safest option.

We use the meropenem desensitization protocol with fourteen steps. The interval between doses is 15 min, total time = 210 min. We observed the patient every 15 min and for 30 min after the final step. After desensitization, the girl received a full therapeutic dose (120mg/kg/day) for 14 days and had no reactions.

Conclusion

Most drug desensitization protocols focus on adults and have been adapted for children. Pediatric patients undergoing desensitization have specialized needs including not only different medications but also volume of intravenous fluids and dosing restrictions and consideration of developmental level and emotional responses to high-risk procedures.