TABLE 1

Summary of significant triazolam and indiplon effects


Measure

Drug vs. Placebo Comparisona

High-Dose Comparisonb

Slope Comparisonc
Triazolam vs. PL
Indiplon vs. PL
Triazolam vs. Indiplon
Triazolam vs. Indiplon
Behavioral performance
    (psychomotor/cognitive)
    Balance - - NS NS
    Circular Lights - - TRZ > IND TRZ > IND
    DSST attempted - - TRZ > IND TRZ > IND
    DSST correct - - NS TRZ > IND
    Digit Recall (long delay) - NS NS TRZ > IND
    Word Recognition - - NS NS
    Word Recall - - NS NS
Observer ratings
    Drug strength + + NS NS
    Sedation/sleepiness + NS NS NS
    Sleep time (4 h after administration) + + TRZ > IND TRZ > IND
    Muscle relaxation (locomotor) + + NS NS
    Muscle relaxation (nonlocomotor) + + NS TRZ > IND
    Impaired posture + + NS NS
    Impaired speech + + NS NS
    Confusion/disorientation + + NS NS
Participant ratings of drug effect and strength
    Drug effectd (SEQ, VAS) + + NS NS
    Strengthd (DEQ, NDQ) + + NS NS
Participant ratings of somatic symptoms
SEQ
    Depressant or sedating + + NS NS
    Sleepy + + NS TRZ > IND
    Tired or lazy + + NS NS
    Fatigued or weak + + NS TRZ > IND
    Comfortable + + NS NS
    Easy going or mellow + + NS NS
    Limp or loose + + NS NS
    Unsteady + + NS NS
    Relaxed + + NS NS
    Confused or disoriented + + NS NS
    Difficulty concentrating + + NS NS
    Mentally slowed down + + NS NS
    Forgetful + + NS NS
    Blurred vision + + NS NS
    Light-headed or dizzy + NS NS NS
VAS
    Drowsy + + NS TRZ > IND
    Sedated + + NS TRZ > IND
    Impaired + + NS NS
    Forgetful + + NS NS
    Difficulty concentrating + NS NS NS
ARCI
    PCAG subscale + + NS NS
Participant ratings of “positive” drug effects
    Liked (VAS, SEQ) + + NS NS
    Likingd (DEQ, NDQ) + + NS NS
    Good effectsd (VAS, SEQ, NDQ) + + NS NS
Ratings of “negative” drug effects
    Bad effects (SEQ) + NS NS NS
Measures of reinforcement
    Take Again (NDQ) + + NS NS
    Worth (NDQ) + + NS NS
    Willing to pay (NDQ) + + NS NS
    Crossover Point (Multiple Choice Procedure)
NS
+
NS
NS
  • IND, indiplon; TRZ, triazolam; SEQ, Subjective Effects Questionaire; VAS, Visual Analog Scale; DEQ, Drug Effect Questionnaire; NDQ, Next-Day Questionnaire; ARCI, Addiction Research Center Inventory.

  • a These two columns show the results of post hoc comparisons of placebo vs. 0.25, 0.5, and 0.75 mg of triazolam and of placebo vs. 30, 50, and 80 mg of indiplon (n = 21). Symbol (+ or -) indicates that at least one dose of the drug was significantly different from placebo (p < 0.05); symbol (+ or -) also indicates the direction of the drug effect relative to placebo. NS indicates that no dose of that drug was different from placebo.

  • b This column shows the results of post hoc comparisons of the highest dose of triazolam (0.75 mg) and indiplon (80 mg). The drug to the left of the symbol (>) produced a significantly greater effect. NS indicates that the effects produced by the highest dose of the two drugs were not significantly different (n = 21).

  • c This column shows the results of post hoc comparisons of the slope of the dose effect curves for triazolam and indiplon. The dose-effect curve of the drug to the left of the symbol (>) had a significantly greater slope. NS indicates that the slopes of the two dose-effect curves were not significantly different.

  • d This subjective domain was assessed on more than one questionnaire (shown in parentheses). The statistical summary results shown in the row were identical across the questionnaires.