Warfarin-chloral hydrate interaction. Pharmacological activity and clinical significance.

Abstract

Investigations of the pharmacology and clinical significance of warfarin-chloral hydrate interaction have yielded conflicting results. The effect of chloral hydrate was studied among 14 volunteers during the initiation and the maintenance of long-term warfarin therapy. Prothrombin times were measured twice daily during a double-blind anticoagulant induction experiment in which chloral hydrate and a placebo were administered alternately to nine subjects. Prothrombin times were measured 4 times weekly during a long-term experiment before, during, and after chloral hydrate administration in 10 patients. A minor degree of warfarin potentiation was observed during the induction experiment, but there was no significant change in anticoagulant control during or after chloral hydrate administration in the long-term study. All published data relating to the warfarin-chloral hydrate interaction is reviewed. Warfarin and chloral hydrate interact pharmacologically, but the result is insignificant clinically.