Absorption of oral and intramuscular chlordiazepoxide by alcoholics

The effect of chronic alcoholism on oral and intramuscular plasma levels of chlordiazepoxide (CDX) was assessed. A 50-mg oral dose of CDX resulted in significantly higher plasma levels in the 2 hr following CDX than a 50-mg intramuscular dose administered to acute withdrawing alcoholic subjects. The same CDX dose was administered 7 days later and the same differences were observed between the mean oral and intramuscular plasma levels during the first 2 hr after administration of CDX. Peak concentration occurred significantly sooner after the oral than intramuscular dose of CDX in both the initial dose and the dose given a week later. It was also observed that the areas under the curve for CDX were significantly greater initially than 1 wk later. It is suggested this effect may be at least partially the result of the longer CDX half-lives initially than a week later. The active metabolite, N-desmethylchlordiazepoxide, peaked significantly earlier with the oral dose than with the intramuscular dose after the patient was alcohol free for a week.