Efficacy of activated charcoal versus gastric lavage half an hour after ingestion of moclobemide, temazepam, and verapamil.

OBJECTIVE: To compare the efficacy of activated charcoal and gastric lavage in preventing the absorption of moclobemide, temazepam, and verapamil 30 min after drug ingestion.

METHODS: In this randomized cross-over study with three phases, nine healthy volunteers received a single oral dose of 150 mg moclobemide, 10 mg temazepam, and 80 mg verapamil after an overnight fast. Thirty minutes later, they were assigned to one of the following treatments: 25 g activated charcoal as a suspension in 200 ml water, gastric lavage (10x200 ml), or 200 ml water (control). Plasma concentrations of moclobemide, temazepam, and verapamil were determined up to 24 h.

RESULTS: Activated charcoal reduced the area under the plasma concentration time curve from 0 h to 24 h (AUC0-24 h) of moclobemide and temazepam by 55% (P<0.05) and by 45% (P<0.05), respectively. The AUC0-24 h of verapamil was not significantly reduced by charcoal. Gastric lavage decreased the AUC0-24 h of moclobemide by 44% (P<0.05), but had no significant effect on that of temazepam or verapamil. The peak plasma concentration (Cmax) of moclobemide, temazepam, and verapamil was reduced by 40%, 29% (P<0.05), and 16%, respectively, by activated charcoal. Gastric lavage did not significantly decrease the Cmax of any of these drugs.

CONCLUSION: The absorption of moclobemide, temazepam, and verapamil can be moderately reduced by activated charcoal given 30 min after drug ingestion, while gastric lavage seems to be less effective.