Find a comprehensive guide to possible side effects including common and rare side effects when taking Effexor (Venlafaxine Hydrochloride) for healthcare. Venlafaxine is a serotonin and noradrenaline re-uptake inhibitor medicine. have difficulty getting to sleep (insomnia), and disturbing dreams or nightmares. I was perscribed effexor (venlafaxine XR) for a week then moving up to 75's. he wrote me a 3 Some people have nightmares on it also.
Effexor nightmares - seems