Oral antihistamines reduce the side effects from rapid vancomycin infusion

Area of Science:

• Pharmacology
• Clinical Medicine
• Patient Safety

Background:

• Rapid vancomycin infusion can cause histamine-mediated side effects, including rash and hypotension, known as red man syndrome.
• Clinicians may need to administer vancomycin faster than the recommended infusion time.

Purpose of the Study:

• To evaluate the efficacy of oral antihistamines in preventing clinical endpoints of red man syndrome.
• To compare the effectiveness of oral antihistamines with intravenous (IV) antihistamines.

Main Methods:

• A prospective, randomized, double-blind, placebo-controlled study involving patients receiving vancomycin for elective arthroplasty.
• Patients received either oral antihistamines (diphenhydramine and cimetidine) or placebo one hour before rapid vancomycin infusion.
• Clinical endpoints included rash, hypotension, and vancomycin discontinuation.

Main Results:

• No treated patients developed clinically significant hypotension, compared to 50% in the placebo group (P = 0.001).
• Vancomycin infusion discontinuation occurred in 5% of treated patients versus 50% in the placebo group (P = 0.004).
• Incidence and severity of rash were significantly reduced in patients pretreated with oral antihistamines (P = 0.011 and P = 0.015, respectively).

Conclusions:

• Oral H1 and H2 antihistamine pretreatment is a practical, safe, and cost-effective strategy to mitigate histamine-mediated side effects from rapid vancomycin infusion.
• Oral antihistamines demonstrated comparable effectiveness to IV antihistamines in preventing these adverse events.