Comparison of performance of healthy volunteers given prazepam alone or combined with ethanol. Relation to drug plasma concentrations.
The interaction between a single dose of 20 mg of prazepam and 0.5 g/kg body weight ethanol was investigated in 12 healthy male volunteers by nine objective performance tests, eight visual analogue self-rating scales and measurement of prazepam and ethanol plasma concentrations, using a double-blind three-way crossover design. The volunteers were each given three treatments (prazepam+ethanol, placebo+ethanol and prazepam alone), separated by a 2-week interval. They completed the performance tests before treatment and 1.5 and 4 h thereafter, and the self-rating scales before treatment, 1.5, 4 and 8 thereafter. To determine prazepam and ethanol plasma levels, venous blood samples were drawn before drug intake and 0.25, 0.5, 1, 1.5, 3, 4, 5 and 8 h thereafter. In two of the performance tests: auditory reaction time and digit symbol substitution, the combination of prazepam and ethanol was shown to impair performance more than either drug taken alone 1.5 h after their administration. A similar result was found for the drowsiness scored in the self-ratings. The time needed to complete the two-symbol cancellation test was longer when the subjects received prazepam either alone or combined with ethanol. Simultaneous ingestion of prazepam and ethanol did not alter the bioavailability of either drug.
Girre
C
C
Unité de Pharmacologie Clinique, Hôpital Fernand Widal, Paris, France.
Hirschhorn
M
M
Bertaux
L
L
Palombo
S
S
Fournier
P E
PE
D000293:Adolescent; D000328:Adult; D000428:Alcohol Drinking / Q000097:blood / Q000523:psychology; D001143:Arousal / Q000187:drug effects*; D001288:Attention / Q000187:drug effects*; D004311:Double-Blind Method; D000431:Ethanol / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011222:Prazepam / Q000493:pharmacokinetics / Q000494:pharmacology*; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects*
D000431:Ethanol; D011222:Prazepam