Influence of prokinetics on the gastrointestinal transit and residence times of activated charcoal.

OBJECTIVE To find the effects of prokinetics, saline cathartics and different charcoal doses on the gastrointestinal transit and residence times of activated charcoal (AC). SETTING Five undergraduate volunteers of College of Health Sciences, Nnamdi Azikiwe University, Nnewi Campus, Anambra State, Nigeria, were studied. METHODS After an overnight fast, the volunteers were given 10 g and 20 g AC with and without saline cathartics, in a simple cross-over design in which the subjects served as their own control. In another experiment, the volunteers received 10 g AC and magnesium sulphate, with propantheline (as bromide 15 mg), metoclopramide (as hydrochloride 10 mg), placebo liquid or identical placebo capsule. Gastrointestinal transit and residence times of AC were recorded. RESULTS Increase in the dose of AC significantly (P < 0.05) decreased the transit, but not the residence time of AC. Addition of saline cathartics (Na2SO4 and MgSO4) decreased both the transit and residence times of AC significantly (P < 0.05). Also, administration of propantheline, but not metoclopramide, produced a significant (P < 0.05) decrease in both the transit and residence times of AC. The transit and residence times were statistically (P < 0.05) different in both the magnesium sulphate group, as well as in the placebo liquid and placebo capsule groups. CONCLUSION Cathartic efficiency is enhanced by alteration of gastrointestinal motility with propantheline.