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.