N-desmethyldiazepam physical dependence in dogs.

Abstract

Dogs, surgically implanted with a chronic gastric fistula, were chronically dosed with N-desmethyldiazepam (32 mg/kg/day) in four divided doses to attain N-desmethyldiazepam plasma levels comparable to those observed in dogs dependent on diazepam (60 mg/kg/day). The time course of N-desmethyldiazepam abstinence was studied, beginning not less than 2 weeks after stabilization levels had been achieved. The abstinence syndrome observed after abrupt discontinuation of N-desmethyldiazepam was similar to the diazepam abstinence syndrome but differed in several important aspects. In diazepam-dependent dogs, there was a short burst of tremor very early in withdrawal (approximately 1-2 hr after the last dose of diazepam) that was not seen in N-desmethyldiazepam-dependent dogs. Signs of abstinence such as tremor, hot foot walking and twitches and jerks were more frequently observed in N-desmethyldiazepam-dependent dogs than in diazepam-dependent dogs as were decreases in food and water intake and in body weight. The overall intensity of abstinence, as measured by the Diazepam Withdrawal Abstinence Scale, was greater in N-desmethyldiazepam-dependent dogs than in dogs dependent on either lorazepam or diazepam. Plasma levels of N-desmethyldiazepam and oxazepam were nearly equal in dogs dependent on diazepam or on N-desmethyldiazepam and were 4 to 10 times greater than the plasma levels of diazepam or lorazepam in diazepam- or lorazepam-dependent dogs, respectively. Furthermore, the plasma levels of N-desmethyldiazepam and oxazepam declined much more slowly than the levels of diazepam and lorazepam. These results suggest that physical dependence on diazepam is caused by the accumulation and actions of N-desmethyldiazepam.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: L F McNicholas, W R Martin, T A Pruitt
• Journal: The Journal of pharmacology and experimental therapeutics (J Pharmacol Exp Ther) Vol. 235 Issue 2 Pg. 368-76 (Nov 1985) ISSN: 0022-3565 [Print] United States
• PMID: 3932642 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Nordazepam
• Oxazepam
• Temazepam
• Lorazepam
• Diazepam

Topics

• Analysis of Variance
• Animals
• Body Weight (drug effects)
• Diazepam (adverse effects, analogs & derivatives, blood)
• Dogs
• Drinking (drug effects)
• Energy Intake (drug effects)
• Female
• Lorazepam (adverse effects, blood)
• Muscle Spasticity (chemically induced)
• Nordazepam (adverse effects, blood)
• Oxazepam (adverse effects, blood)
• Paresthesia (chemically induced)
• Substance Withdrawal Syndrome (physiopathology)
• Temazepam (adverse effects, blood)
• Time Factors