Vancomycin hypersensitivity: Synergism with narcotics and “desensitization” by a rapid continuous intravenous protocol

Background: We examined the clinical spectrum of patients with persistent adverse reactions to vancomycin, assessed contributing factors, and evaluated the efficacy and safety of a rapid continuous intravenous “desensitization” protocol in these patients. Methods: Seven patients with serious staphylococcal infections resistant to β-lactam antibiotics whose adverse reactions to vancomycin persisted despite slowing of the vancomycin infusion and pretreatment with H 1-antihistamine were studied. All seven patients underwent a rapid continuous intravenous desensitization protocol with multiple small increases in vancomycin concentration tightly regulated with a syringe pump. Results: Most of the seven patients safely achieved, during the first day, a vancomycin infusion rate (VIR) sufficient, or close to sufficient, to provide the desired vancomycin dose. In three patients there appeared to be a threshold VIR beyond which adverse reactions were repeatedly elicited; these reactions abated when the VIR was slightly lowered. Narcotic administration was found to adversely affect treatment with vancomycin. After concurrent narcotic administration was discontinued in three patients, they and the other four patients successfully completed the full course of treatment with vancomycin. Conclusion: Patients whose adverse reactions to vancomycin did not respond to slowing of the infusion rate and additional H 1-antihistamines can be safely treated with a rapid continuous intravenous desensitization protocol and discontinuance of narcotic administration.