Seven healthy male volunteers had their light sensitivity (melatonin s
uppression) and melatonin phase measured before and after treatment wi
th temazepam (20 mg) for 7 days. Temazepam did not alter the circadian
phase of melatonin secretion (the Dim Light Melatonin Onset, the timi
ng of the peak of secretion), the total melatonin secretion nor the se
nsitivity of melatonin secretion to suppression by full spectrum light
. This is an important negative finding which suggests that the short
half-life benzodiazepine hypnotic temazepam does not confound tests of
light sensitivity or melatonin phase.