Different venlafaxine doses (1, 5, and 10 mg/kg) and saline solution w
ere administered to ten male Wistar rats (Latin-Square design). Compar
ed with saline, venlafaxine produced a dose-related supression of REM
sleep and an increase in wake time while slow wave sleep was reduced.
This effect is similar to the one that has been reported with some tri
cyclic antidepressants.