Influence of antihistamine pretreatment on vancomycin-induced red-man syndrome

Twelve adult male volunteers participated in a double-blind study to determine the effect of pretreatment with histamine and/or histamine2 receptor antagonists on the incidence and severity of vancomycin-induced "red-man syndrome." Subjects received hydroxyzine, 50 mg, ranitidine, 300 mg, hydroxyzine plus ranitidine, or placebo at weekly intervals 2 h before a l-h infusion of vancomycin, 1,000 mg. The extent of erythema was evaluated by burn chart and pruritus was assessed by each subject using a rank scale; symptoms were thus classified a priori as mild, moderate, or severe and their summation determined a global severity score for red-man syndrome. There was no significant intrasubject variation between area under the concentration-time curves for histamine and vancomycin (P greater than .05). Pretreatment with hydroxyzine alone provided significant protection against vancomycin-induced erythema and pruritus (P less than .05) whereas the effect of ranitidine did not differ significantly from placebo. The combination of hydroxyzine and ranitidine offered no advantage over hydroxyzine alone. Similar results were observed for global severity scores. Thus in normal volunteers prior administration of a histamine antagonist (hydroxyzine) provided significant protection against vancomycin-induced red-man syndrome compared to that afforded by placebo. There was no significant benefit from the histamine antagonist alone or by its addition to a histamine antagonist.