An isolated case report suggests that hypotensive effects of therapid infusion of vancomycin may occur more readily in thosewho are already vasodilated with nifedipine, but it seems likelythat effects seen were due to rapid infusion alone.
Clinical evidence,mechanism, importance and management
A man with severe systemic sclerosis was hospitalised for Raynaud’s phenomenon and dental extraction. After being started on nifedipine 40mg daily,he was given intravenous vancomycin 1 g in 200 mL of dextrose 5 % over 30 minutes. After 20 minutes he experienced a severe headache and was found to have a marked macular erythema on upper trunk, head, neck and arms. His blood pressure fell to 100/60 mmHg and his pulse rate was 90 bpm. He recovered spontaneously (See reference number 1). The authors of report acknowledge possibility of red-man syndrome caused by vancomycin, and suggest that it may occur more readily in those already vasodilated with nifedipine. However, given that this is an isolated report, and vancomycin was given over 3 times faster than recommended rate, it seems likely that this is purely an adverse effect of vancomycin.
1. Daly BM,Sharkey I. Nifedipine and vancomycin-associated red man syndrome. Drug Intell Clin Pharm (1986) 20, 986.