two months after I began the weaning process, after I was totally off the Paxil for a week or so, the withdrawal symptoms went away. Zoloft withdrawl symptoms can begin within eight hours of a missed dose and can last from one to eight weeks. The information provided should not be construed to indicate that Paxil is safe, effective or appropriate. This antidepressant drug information does Effexor Xr And Cause Weight Gain endorse Paxil, diagnose patients or recommend therapy. Side affects of effexor. Generally the drugs that are metabolized most quickly cause more Effexor Xr And Cause Weight Gain symptoms, Effexor Xr And Cause Weight Gain said. Cases like Wilson's would be virtually nonexistent if physicians took more care in weaning their patients off antidepressants, said Philip Ninan, vice president for neuroscience at Wyeth, the maker of Effexor. Venlafaxine had no effect Effexor Xr And Cause Weight Gain the pharmacokinetics of lithium. Dosage adjustment based upon Effexor Xr And Cause Weight Gain or gender is generally not necessary (See Dosage). Effexor Effexor Xr And Cause Weight Gain ODV renal. with MAO inhibitors should not be started until two weeks after discontinuation weeks.