Jump to Ativan - Action, if known: Benzodiazepine--slows central nervous system activity. Potentiates digoxin and phenytoin; decreases effect of L-Dopa. Dec 20, - Comparative single-dose kinetics and dynamics of lorazepam, alprazolam, prazepam, and placebo Sedative and DSST-impairing effects of lorazepam were of slower onset but longer duration than Claire L O'Reilly. Levy, G., O'Reilly, R.A., Aggeler, P.M., & Keech, G.M. Pharmacokinetic analysis of the effect of barbiturates on the anticoagulant action of warfarin in man. L.F. The effect of lorazepam of hypertension-associated anxiety: a double-blind study.