Meperidine hydrochloride was evaluated in a prospectively randomized double-blind study for its effectiveness in stopping shaking chills occurring with amphotericin B infusions. Seven patients were randomized on multiple occasions for a total of 19 reactions. In the meperidine group, nine of nine reactions stopped within 30 minutes of the administration of meperidine, with a mean cessation time of 10.8 minutes. The placebo group had a mean time of 37.4 minutes to cessation of reactions with three of ten reactions subsiding spontaneously. The mean dose of meperidine hydrochloride for cessation of reaction was 45 mg. The comparisons between meperidine and placebo for cessation of reaction within 30 minutes and the mean time to cessation of reaction were significantly different. Side effects with meperidine were minimal and less severe than the shaking chills and fever seen with amphotericin B infusions. Meperidine can eliminate these reactions more effectively and more rapidly than simply discontinuing the amphotericin B.