A double-blind comparison of prazepam with diazepam, chlorazepate dipotassium and placebo in anxious out-patients.

The study compared prazepam with diazepam, chlorazepate dipotassium, and placebo in the treatment of anxious out-patients. Patients were screened for participation in the study to be sure they met the criteria for inclusion. Patients were excluded if they had complicating physical or mental problems. All patients signed an informed consent. Seventy-three patients entered the study, thirteen did not complete at least two weeks of treatment and were not used in the data analysis. Of these thirteen, ten did not return and were lost to follow-up, tow entered the hospital for reasons unrelated to the drug study, and one patient on diazepam was terminated because of increased anxiety. Six patients were used in the data analysis, thirty-six males and twenty-four females with an age range of 21-61 years. Side-effects were minimal. Drowsiness was reported by two people in the placebo group, one taking chlorazepate dipotassium, three on prazepam and one on diazepam. One diazepam patient reported nausea and vomitting. Scores on the Zung Self-Rating Scale for Anxiety showed all three drug groups to be superior to placebo. The Hopkins Symptom Check-list found prazepam and diazepam to be superior to placebo and chlorazepate. No differences among the groups were found in the Hamilton Anxiety Scale. Prazepam may offer advantages over the other available benzodiazepines since it may be more readily absorbed than chlorazepate and has less side-effects than diazepam.