Persistence of tolerance to methamphetamine-induced monoamine deficits.

Methamphetamine is a highly addictive and potent stimulant, the use of which has increased significantly in recent years. In addition to the severe behavioral and societal consequences associated with methamphetamine abuse, methamphetamine can cause persistent damage to monoaminergic nerve terminals in rats, as measured by either monoamine concentrations or activity of the rate limiting synthetic enzymes, tyrosine hydroxylase and tryptophan hydroxylase. Repeated, sub-neurotoxic doses of methamphetamine, however, can cause rats to become resistant to the neurotoxic effects of multiple high-dose administrations of methamphetamine; a phenomenon known as tolerance.

Opiate recidivism in a drug-treatment program: comparison of hair and urine data.

The objective of this preliminary study was to determine whether hair can be used as an adjunct specimen for the monitoring of opiate use in a drug-treatment program. Subjects (n = 10) initiating clinical therapy for opiate addiction were monitored for up to 17 weeks with hair and urinalysis. Questionnaires were administered weekly to document hair cuts and chemical treatments.