From what I understand Effexor converts to Pristiq in the body and therefore the difference is negligible.  Effexor will be going off patent in a year or so.  This is an attempt to extend the patent of a popular drug.  It costs about 10% more.

I was on Effexor xr for 6 years, taking between 225 and 375 mgs a day. The only side effects I ever had were dry mouth and constipation. It worked better for me than any other antidepressant I had ever tried.

7 weeks ago my doctor put me on the 'New Effexor', Pristiq. After taking it for 3 weeks, I was so emotional, I cried over everything. My doctor told me to take two tabs instead of the one. At the end of a week, I called him again. I wasn't crying anymore, but was so aggitated and restless, I was miserable. I've been taking one and a half tabs for 4 days, I'm crying again, but, also, still aggitated and restless.

Effexor never did these things to me, so I don't see how they can be so close together chemically. I'm not taking any tonight, or any other night.

I'm sure it doesn't effect everyone that way.

Jolene

Actually, Effexor and Pristiq are related but Pristiq is a structurally novel compound.  They have the same active metobolite (which is thought to have the beneficial effects) but Pristiq has succinate salt added to it which allows for a predictable concentration of the medication.  What all this means is that most patients will be able to stay at the starting dose of 50 mg with very good results.  There have been very low incidences of side effects, little to no weight gain and sexual side effecfts don't seem to be an issue either.

The patent on effexor xr is good until 2010 and Pristiq is actually less expensive than effexor xr with a great co-pay program and every improving formulary coverage.

Some patients my be fine staying on Effexor XR but for anyone initiating therapy or someone who experience side effects Pristiq is a really good option.  I know, I switch from 150 Effexor to 50 Pristiq and haven't felt this good in years!

My doctor swears by pristiq.  I have been taking effexor for a couple of years (150 mg currently).  My girlfriend was sick of the side effects so I decided to give it a try.  The physician's assistant said it was fine to switch from one to another.  BAD MOVE.  ANYONE TELLING YOU THAT YOU CAN DO THIS IS LYING OR IGNORANT.  I HAD A TOTAL MELTDOWN WITHIN FOUR DAYS.  WANTED TO KILL MYSELF...ENDED UP IN A CLOSET CRYING FOR NO APPARENT REASON.  I EVEN PISSED THE BED.  I'M A 39 YEAR OLD MAN FOR HEAVEN'S SAKE.  DO NOT GO FROM ONE TO THE OTHER HASTILY.  There is a way to do it safely.  It involves coming off the effexor slowly while introducing Pristiq simultaneously.  I'm not a doctor so I'm not going to say how to do it.  Don't rely on a physician's assistant to tell you how to take medication...get it from a real MD.