PT - JOURNAL ARTICLE AU - Mohsen A. Hedaya AU - Wei-Jian Pan TI - Effect of Alcohol Coadministration on the Plasma and Brain Concentrations of Cocaine in Rats DP - 1997 May 01 TA - Drug Metabolism and Disposition PG - 647--650 VI - 25 IP - 5 4099 - http://dmd.aspetjournals.org/content/25/5/647.short 4100 - http://dmd.aspetjournals.org/content/25/5/647.full SO - Drug Metab Dispos1997 May 01; 25 AB - We investigated the effect of intravenous alcohol coadministration on the pharmacokinetics of cocaine in awake, freely moving rats using the microdialysis technique. Alcohol coadministration resulted in faster rate of cocaine absorption after intraperitoneal administration leading to higher cocaine plasma concentration. The higher plasma cocaine concentration resulted in a proportional increase in the cocaine brain extracellular fluid concentration. However, cocaine brain extracellular fluid/plasma distribution ratio, determined from the ratio of the corresponding cocaine area under the concentration-time curves, was not affected by alcohol coadministration. Cocaethylene was detected only after administration of cocaine + alcohol. The brain extracellular fluid/plasma distribution ratio of cocaethylene was similar to that of cocaine. The higher cocaine concentrations in plasma and brain extracellular fluid, in addition to the formation of the pharmacologically active metabolite cocaethylene are, at least partially, responsible for the increased cocaine effects produced after administration of this drug combination. The American Society for Pharmacology and Experimental Therapeutics