Erythromycin is more effective than metoclopramide in the treatment of feed intolerance in critical illness

Objective: This study aimed to a) compare the efficacy of metoclopramide and erythromycin in the treatment of feed intolerance in critical illness; and b) determine the effectiveness of "rescue" combination therapy in patients who fail monotherapy. Design: Randomized controlled trial. Setting. Level III mixed medical and surgical intensive care unit. Patients: Ninety mechanically ventilated, medical patients with feed-intolerance (gastric residual volume >= 250 mL) Interventions: Patients received either metoclopramide 10 mg intravenously four times daily (n = 45) or erythromycin 200 mg intravenously twice a day (n = 45) in a double-blind, randomized fashion. After the first dose, nasogastric feeding was commenced and 6-hourly nasogastric aspirates were performed. If a gastric residual volume :250 mL recurred on treatment, open-label, combination therapy was given. Patients were studied for 7 days. Successful feeding was defined as 6-hourly gastric residual volume <250 mL with a feeding rate >= 40 mL/hr. Measurements and Main Results: Demographic data, blood glucose levels, and use of inotropes, opioids, and benzodiazepines were similar between the two groups. After 24 hrs of treatment, both monotherapies reduced the mean gastric residual volume (metoclopramide, 830 +/- 32 mL to 435 +/- 30 mL, p <.0001; erythromycin, 798 +/- 33 mL to 201 +/- 19 mL, p <.0001) and improved the proportion of patients with successful feeding (metoclopramide = 62% and erythromycin = 87%). Treatment with erythromycin was more effective than metoclopramide, but the effectiveness of both treatments declined rapidly over time. In patients who failed monotherapy, rescue combination therapy was highly effective (day 1 = 92%) and maintained its effectiveness for the study duration (day 6 = 67%). High pretreatment gastric residual volume was associated with poor response to prokinetic therapy. Conclusions. In critical illness, erythromycin is more effective than metoclopramide in treating feed intolerance, but the rapid decline in effectiveness renders both treatments suboptimal. Rescue combination therapy is highly effective, and further study is required to examine its role as the first-line therapy.