The effects of the α2-adrenoceptor antagonist idazoxan on sleep in normal volunteers

Abstract

The effects of idazoxan, a novel antidepressant that is a potent and selective α₂-adrenoceptor antagonist, were studied on sleep. Twelve normal male volunteers had sleep recordings made using the Oxford ambulatory system (Medilog 9000) with subsequent analysis by automatic sleep staging and visual inspection. Idazoxan was given in a dose of 40 mg three times a day for 21 days. Sleep recording on day 3 demonstrated markedly reduced indices of rapid eye movement (REM) sleep, although other sleep parameters were only minimally affected. The effect on REM persisted unchanged at day 18, however on the second day after withdrawal a rebound in REM measures was observed. These data show that idazoxan has an effect on sleep which is very similar to that of other antidepressants, and emphasize a role for noradrenaline in the regulation of REM sleep.