Apart from weight gain, the complaints were found to be experienced significantly more severely by the high-dose group. Six patients discontinued venlafaxine due to intolerable side-effects but only two of these patients were on a high dose. There was a tendency for mildly raised blood pressure in 10% of patients on an average dose of 342 mg/day. However, no difference between the two groups. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Ali on side effects of high doses of effexor: Both mental and physical side effects with valproic acid are usually dose related (higher the higher the dose). However, you might notice that the effectiveness (reduction in mental symptoms) is also dose related. What. Initial Treatment. The recommended starting dose for Effexor is 75 mg/day, administered in two or three divided doses, taken with food. Depending on tolerability and the need for further clinical effect, the dose may be increased to 150 mg/day. Side Effects. See also Warning section. Nausea, drowsiness, dizziness, dry mouth, constipation, loss of appetite, blurred vision, nervousness, trouble sleeping. This report is to point out a rather disturbing effect I've noticed from long term high-dose SNRI (and possibly SSRI) usage. I had experimented with Methylone (M1) and MDAI dozens of times in the past, sometimes taking M1 a few times in one night. Venlafaxine (Effexor) is a prescription medicine used to treat depression. It belongs to a class of drugs known as selective serotonin and norepinephrine reuptake inhibitors, or SNRIs. Venlafaxine works by increasing the availability of serotonin and norepinephrine in your brain. Hey all, recently had my Effexor XR dose bumped up from 75mg to 150. I'm on day 10 or so, and the side effects have been horrible. Dry mouth, high anxiety, light headed and foggy, like I'm on the edge of rolling or a panic attack or something. Our Effexor Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. This is not a complete list of side effects and others may occur. Effexor XR Facts. Uses Major depressive disorder, generalized anxiety disorder, social anxiety disorder, panic disorder; Side Effects Suicidal thoughts and behavior, serotonin syndrome, changes in blood pressure, abnormal bleeding, eye problems, withdrawal symptoms, birth defects, miscarriage Along with its needed effects, venlafaxine (the active ingredient contained in Effexor) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.