Is it safe to take nyquil 4 hours after taking effexor (venlafaxine)?

Not a good idea: Effexor (venlafaxine) should be taken in the morning to improve depression, increase mental energy, and to prevent insomnia. If you take NyQuil because you cannot sleep, you might benefiting from the 25-50 mg of diphenhydramine (Benadryl) on it. Please seek advise regarding insomnia right away to prevent further problems. Check your blood pressure regularly because Effexor tends to increase BP.