GASTROINTESTINAL SIDE-EFFECTS OF INTRAVENOUS ERYTHROMYCIN - INCIDENCE AND REDUCTION WITH PROLONGED INFUSION TIME AND GLYCOPYRROLATE PRETREATMENT

OBJECTIVE: To determine the frequency of gastrointestinal toxicity due to intravenous (IV) erythromycin and to attempt to decrease this toxicity by prolonging the infusion time of erythromycin and/or pretreating with the peripheral anticholinergic, glycopyrrolate 0.1 mg IV. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: General medical wards of a tertiary medical center. PATIENTS: A total of 51 hospitalized patients 18 years of age or older who were prescribed IV erythromycin lactobionate (EMLB) 500 mg every 6 hours by their attending physicians. INTERVENTIONS: Each of eight consecutive infusions of EMLB was randomly assigned to one of four groups: control-30-minute infusion/placebo pretreatment; 60/P-60-minute infusion/placebo pretreatment; 30/G-30-minute infusion/glycopyrrolate pretreatment; and 60/G-60-minute infusion/glycopyrrolate pretreatment. MAIN OUTCOME MEASURES: Each infusion was accompanied by a questionnaire in which patients rated the magnitude of nausea and vomiting on a scale of 1 (no toxicity) to 9 (severe toxicity). Scores for both nausea and vomiting were added together for a total toxicity score ranging from 2 to 18. A total score of greater than 8 was defined as clinically important. RESULTS: The 51 patients received a total of 356 infusions with gastrointestinal toxicity occurring in 27 of 51 (53%) patients. Among patients under the age of 40, 22 of 33 (67%) experienced toxicity compared with only five of 18 patients (28%) over the age of 40 (p = 0.018). Clinically important toxicity was seen in 19 of 51 patients (37%), including five who withdrew during the study because of severe nausea and vomiting. In this group, the combination of a 60-minute erythromycin infusion and glycopyrrolate pretreatment decreased clinically important toxicity by 79% from 47% to 10%, a statistically and clinically significant 37% (95% CI, 14% to 60%) difference (p = 0.007). CONCLUSIONS: Gastrointestinal toxicity associated with the IV infusion of erythromycin is common and is more likely to occur in younger patients. A 1-hour infusion of erythromycin combined with pretreatment with glycopyrrolate, 0.1 mg IV, is effective in reducing this toxicity.