Blood pressure regulation was studied in 12 healthy elderly subjects after double-blind randomised administration of placebo, 15 mg and 30 mg temazepam at 10.00 h and 22.00 h. 2. Supine and standing heart rate and blood pressure were measured after daytime administration and supine measurements were obtained during sleep. 3. Temazepam caused a fall in systolic blood pressure and an increase in heart rate after morning administration. These changes were greater in the standing position and were dose-dependent; for standing blood pressure and heart rate 1 h after administration there was a 7 mm Hg fall and 6 beats min-1 increase after 15 mg temazepam and a 10 mm Hg fall and 8 beats min-1 increase after 30 mg temazepam. Temazepam magnified the fall in systolic blood pressure and increase in heart rate that occurred with standing. Temazepam enhanced the fall in systolic blood pressure that occurred during sleep (mean +/- s.d.; placebo: -23 +/- 10 mm Hg, 15 mg temazepam: -31 +/- 13 mm Hg, 30 mg temazepam: -36 +/- 14 mm Hg). 4. These changes in blood pressure regulation caused by temazepam may have clinical importance in some elderly individuals.
