Current study results from the report, 'Effects of the combination of metyrapone and oxazepam on Cocaine and food self-administration in rats,' have been published. "For several years, our laboratory has investigated the role for the HPA axis in Cocaine reinforcement. Two classes of drugs that we have studied include corticosterone synthesis inhibitors (e.g., metyrapone) and benzodiazepine receptor agonists (e.g., oxazepam)," scientists in the United States report (see also Behavior).

"In the experiments described in this manuscript, we tested the effects of various doses of metyrapone and oxazepam against several doses of self-administered cocaine. Behavioral, endocrine and pharmacokinetic measures of the effects of the combination of metyrapone and oxazepam on Cocaine reward are presented. Combinations of metyrapone and oxazepam at doses that produced no observable effects when administered separately significantly reduced Cocaine self-administration without affecting food-maintained responding during the same sessions. Changes in pharmacokinetics or endocrine function do not appear to mediate these effects, suggesting a central mechanism of action," wrote N.E. Goeders and colleagues, Louisiana State University, Health Science Center.

The researchers concluded: "Therefore, although these drugs produce their effects through distinct mechanisms, an additive effect on Cocaine self-administration is obtained when these drugs are administered together, suggesting that combinations of low doses of metyrapone and oxazepam may be useful in reducing Cocaine seeking with a reduced incidence of unwanted side effects and a decreased potential for abuse."

Goeders and colleagues published their study in Pharmacology, Biochemistry and Behavior (Effects of the combination of metyrapone and oxazepam on Cocaine and food self-administration in rats. Pharmacology, Biochemistry and Behavior, 2008;91(1):181-9).

For more information, contact N.E. Goeders, Toxicology & Neuroscience, Dept. of Pharmacology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130 USA..

Publisher contact information for the journal Pharmacology, Biochemistry and Behavior is: Pergamon-Elsevier Science Ltd., the Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England.