Multi-centre general practitioner comparative study of controlled-release ('Valrelease') and conventional ('Valium') forms of diazepam in patients suffering from anxiety.

A multi-centre, double-blind, parallel group study was carried out in 114 patients with an anxiety disorder to compare the effectiveness of diazepam given as 5 mg 3-times daily or as a once-daily 10 mg dose of a controlled-release formulation designed to provide smooth drug concentrations over about 24 hours, without the heavy sedation caused by a high initial peak. Patients were allocated at random to receive one or other dosage regimen for 1 week and treatment could be continued for a further week if necessary. Clinical assessments of response to treatment showed that whilst both formulations were equally effective in providing symptomatic improvement, a much higher proportion of patients on controlled-release diazepam were ready to terminate treatment after 1 week, having attained the desired relief of symptoms. Moreover, as indicated by patient diary records, significantly fewer patients on the controlled-release formulation complained of drowsiness in the morning and evening.