Decreased pentobarbital sleeptime following a single intraperitoneal injection of cedar-derived sesquiterpenes

Within one day after a single IP injection of cedar sesquiterpenes into mice, pentobarbital sleeptime was reduced by 40%. The estimated ED50 is 50 mg terpenes/kg body weight. The mice recovered from this terpene-induced reduction in the strength of hypnosis within 6 days after the terpene injection. The potency of the terpenes, the rapidity of their action, and the duration of their effectiveness in modulating a drug response suggest their usefulness as a pharmacological tool.