Tuesday, February 28, 2012

Donepezil (Aricept) blocks cocaine's, but not methamphetamine's, effects

Donepezil is used to manage the early symptoms of Alzheimer's Disease and is available as the Aricept preparation.  It is a cholinesterase inhibitor, and increases acetylcholine levels in brain.  Our lab group recently reviewed a paper by Takamatsu and colleages on donepezil's efficacy to block the conditioned reinforcing (place preference) and locomotor activating properties of cocaine and methamphetamine in mice.  While it diminished the effects of cocaine, it was ineffective to alter methamphetamine's effects in this study.  Considering the efficacy of other cholinergic ligands (e.g., lobeline) to alter methamphetamine's effects, these findings were surprising to us.

Reference - Takamatus Y. et al. (2006) Differential effects of donepezil on methamphetamine and cocaine depedencies.  Ann NY Acad Sci 1074: 418

Thursday, February 23, 2012

Methamphetamine place preference

Our laboratory at the University of Missouri is working to develop a place preference assay to evaluate the conditioned-rewarding properties of methamphetamine in mice.  We were able to develop a cocaine place preference procedure, but have been struggling with methamphetamine.  Any suggestions would be appreciated!

Associated Press - National Meth Lab Busts Up in 2011

From the Associated Press...

Methamphetamine lab seizures rose nationally again in 2011, further evidence that the powerfully addictive and dangerous drug is maintaining a tight grip on the nation's heartland, according to an Associated Press survey of the nation's top meth-producing states.

Do these findings reflect a decrease in methamphetamine use nationwide?

Reference - National Meth Lab Busts Up in 2011. Jim Salter, Associated Press cited in the Columbia Missourian, Feb. 22,2012

Modafinil for the treatment of methamphetamine abuse?

In a recent  article in the journal Drug and Alcohol Dependence Ann L. Anderson and colleagues evaluated the efficacy of the psychostimulant modafinil as a treatment for methamphetamine abuse. This was a relatively-large study of patients dependent on methamphetamine who received (double-blind design) modafinil (200 or 400 mg) or placebo over twelve weeks.  Despite the animal research that suggests that modafinil could block or replace methamphetamine's "addictive" effects, there was no significant impact of modafinil treatment on methamphetamine use in these patients.  The authors suggest a problem was that the patients did not comply with the modafinil treatment regimen.

Reference - Modafinil for the Treatment of Methamphetamine Dependence, A.L. Anderson, et. al. (2012) Drug & Alcohol Dependence 120: 135.