Bromazepam and lorazepam in generalized anxiety: a placebo-controlled study with measurement of drug plasma concentrations.

Sixty outpatients with a diagnosis of generalized anxiety were randomly assigned to 4 weeks of treatment with bromazepam, lorazepam or placebo, following a 1-week placebo washout period. There was no significant difference in the anxiolytic effects of bromazepam and lorazepam, both of which were superior to placebo. However, lorazepam-treated patients tended to have a more depressed mood than those treated with bromazepam. Drug-treated patients had consistently less cognitive impairment than those treated with placebo, the difference being statistically significant (P less than .05) in the case of bromazepam. The most frequent side-effects reported with each drug were drowsiness, which tended to subside with time, and depression, which tended to emerge toward the end of the 4-week period. There was a positive correlation (r = 0.64) between age and bromazepam plasma concentration per unit dose, adjusted for weight, and a negative correlation (r = -0.50) between weight and lorazepam plasma concentration per unit dose, adjusted for age.