The effects of alprazolam alone and combined with alcohol on central integrative activity.

The effects of alprazolam 1 mg both alone and in combination with 0.5 g/kg of alcohol were examined on self-ratings of intoxication and measures of central and peripheral activity such as EEG, auditory evoked response, tremor at 90, 150 and 210 min post drug. Forty-eight healthy volunteers were assigned randomly to 4 independent groups who received: alprazolam and placebo drink, alprazolam and alcohol, placebo capsule and alcohol, placebo capsule and placebo drink respectively. Alprazolam decreased the amplitudes of the 3 potentials of the evoked response, decreased activity in the 8-13 Hz and increased activity in the 13.5-26 Hz wavebands of the EEG and decreased the frequency at which fusion was perceived. Alcohol prolonged reaction time and increased tremor. The effects were not always additive and alprazolam was dominant in the combination.