Methamphetamine and ethanol interactions in humans.
OBJECTIVE
Methamphetamine and ethanol are commonly used together. We examined the effects of intravenous methamphetamine (30 mg), oral ethanol (1 gm/kg), and the combination of methamphetamine (30 mg) and ethanol (1 gm/kg).


METHODS
Eight methamphetamine and ethanol users were studied in a double-blind, double-placebo, within-subject, balanced Latin-square design. Ethanol was administered in six drinks over 30 minutes. Methamphetamine was injected 60 minutes after the first drink was begun. Cardiovascular, subjective, and neuropsychologic effects of the drug combinations were measured for 6 hours. Methamphetamine and amphetamine in plasma and urine were measured by capillary gas chromatography for 48 hours. Data were analyzed by repeated-measures ANOVA.


RESULTS
Compared with methamphetamine alone, the combination increased heart rate but decreased systolic blood pressure. The net cardiovascular effect was an increase in rate pressure product, an index of cardiac work and myocardial oxygen consumption. The combination diminished the subjective effects of ethanol while not affecting the subjective effects of methamphetamine. Methamphetamine pharmacokinetics were not altered by the concurrent administration of ethanol, with the exception of lowering the apparent volume of distribution at steady state for methamphetamine.


CONCLUSIONS
As a potent sympathomimetic drug with alpha-agonist-like effects, methamphetamine increased systolic blood pressure, with minimal change in heart rate. The concurrent administration of methamphetamine and ethanol increased cardiac work, which could produce more adverse cardiovascular effects than either drug taken alone. The increased perceived global intoxication may explain the popularity of this drug combination.
Mendelson
J
J
Drug Dependence Research Center, Langley Porter Psychiatric Institute, University of California, San Francisco 94143-0984, USA.
Jones
R T
RT
Upton
R
R
Jacob
P
P
D000284:Administration, Oral; D000328:Adult; D004311:Double-Blind Method; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006207:Half-Life; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008694:Methamphetamine / Q000493:pharmacokinetics / Q000494:pharmacology*; D009483:Neuropsychological Tests
D000431:Ethanol; D008694:Methamphetamine