The effect of activated charcoal and hyoscine butylbromide alone and in combination on the absorption of mefenamic acid.

Abstract

Mefenamic acid 500 mg orally was administered to nine healthy volunteers on four occasions 7 days apart. On two occasions allocated at random, activated charcoal (2.5 g of medicoal) was administered 1 h after the drug. Hyoscine butylbromide (20 mg intramuscularly) was given immediately after mefenamic acid on one of these occasions, and on one occasion after mefenamic acid without charcoal. Hyoscine significantly delayed the time to maximum mefenamic acid concentrations but did not affect the area under the plasma concentration-time curve. Charcoal reduced the area under the plasma concentration curve by 36% and charcoal and hyoscine reduced the area under the plasma concentration curve by 42% from their respective control values. We conclude that early charcoal administration in a ratio of 5 g to 1 g of drug effectively reduces the area under the plasma concentration-time curve after oral mefenamic acid administration. Early charcoal administration may be of value therefore in reducing the toxicity of mefenamic acid after deliberate or accidental overdosage.

Oral Activated Charcoal in the Treatment of Intoxications

“…7) and mefenami c acid in humans (El-Bah ie et al 1985;Olkkola & Neuvonen 1984a ,b). 7) and mefenami c acid in humans (El-Bah ie et al 1985;Olkkola & Neuvonen 1984a ,b).…”

The Use of Cholecystokinin as an Adjunctive Treatment for Toxin Ingestion

“…El-Bahie, et al conducted an analogous study using hyoscine, an anticholinergic agent, in a nine-person, human volunteer study (13). El-Bahie, et al conducted an analogous study using hyoscine, an anticholinergic agent, in a nine-person, human volunteer study (13).…”

The effect of charcoal on mefenamic acid elimination.

“…In a previous study we have shown that activated charcoal significantly reduced the absorption of mefenamic acid (ElBahie et al, 1985). Furthermore it was observed that in some volunteers there was evidence of a second peak plasma concentration which may indicate an enterohepatic or entero-enteral recirculation.…”

“…Evidence of efficacy was, however, based on animal data only. We have recently shown that activated charcoal significantly reduces the absorption of a therapeutic dose (500 mg) of mefenamic acid in man when given in a ratio of 5:1 (ElBahie et al, 1985). The effect was increased slightly on concommitant administration of hyoscine-N-butylbromide 20 mg i.m., to simulate delayed gastric emptying, a feature in overdose.…”