Alcohol tolerance in humans is enhanced by prior caffeine antagonism of alcohol-induced impairment

Exp Clin Psychopharmacol. 2003 Feb;11(1):9-17. doi: 10.1037//1064-1297.11.1.9.


The author tested the hypothesis that a history of drug-induced antagonism of alcohol impairment would enhance alcohol tolerance in humans. Groups of participants (N = 21) repeatedly performed a psychomotor task under different drug treatments: 0.65 g/kg alcohol, 4 mg/kg caffeine, or both drugs combined. Tolerance to a 0.65 g/kg alcohol dose challenge was then tested. Results showed that a history of combined alcohol and caffeine administrations increased alcohol tolerance compared with an exposure history to either drug alone. The findings contribute to the understanding of the complexities of polydrug use history and provide a useful model to examine how alcohol tolerance might be affected by a history of coadministration with other drugs (e.g., cocaine and nicotine).

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Alcohol Drinking / psychology
  • Caffeine / pharmacology*
  • Central Nervous System Depressants / antagonists & inhibitors*
  • Central Nervous System Depressants / pharmacology*
  • Central Nervous System Stimulants / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Tolerance
  • Ethanol / antagonists & inhibitors*
  • Ethanol / blood
  • Ethanol / pharmacology*
  • Female
  • Humans
  • Hypnotics and Sedatives
  • Male
  • Psychomotor Performance / drug effects*


  • Central Nervous System Depressants
  • Central Nervous System Stimulants
  • Hypnotics and Sedatives
  • Caffeine
  • Ethanol