Comparing single and cumulative dosing procedures in human triazolam discriminators

This study evaluated a cumulative dosing procedure for drug discrimination with human participants. Four participants learned to discriminate triazola m (0.35 mg/70 kg) from placebo. A crossover design was used to compare the results under a single dosing procedure with results obtained under a cumul ative dosing procedure. Under the single dosing procedure, a dose of triazo lam (0, 0.05, 0.15, or 0.35 mg/70 kg) or secobarbital (0, 25, 75, or 175 mg /70 kg) was administered 45 min before assessment. Determining each dose-ef fect curve thus required four sessions. Under the cumulative dosing procedu re, four doses of triazolam (0, 0.05, 0.10, and 0.20 mg/70 kg) or secobarbi tal (0, 25, 50, and 100 mg/70 kg) were administered approximately 55 min ap art, producing a complete dose-effect curve in one four-trial session. Rega rdless of procedure, triazolam and secobarbital produced discriminative sti mulus and self-reported effects similar to previous single dosing studies i n humans. Shifts to the right in cumulative dose-effect curves compared to single dose-effect curves occurred on several self-report measures. When qu alitative stimulus functions rather than quantitative functions are of inte rest, application of cumulative dosing may increase efficiency in human dru g discrimination.