Antidepressant Comparison: Are Pristiq and Effexor the Same?

Does Pristiq Just Serve to Extend the Effexor Patent?

If you live in the US, you’ve probably seen all the commercials for the new and pastel-pink-coloured antidepressant Pristiq. (Yes, prescribed for depression.) Pristiq is new and has a huge marketing push behind it and is a selective serotonin norepinephrine reuptake inhibitor (SNRI) antidepressant. In other words, it’s an antidepressant that works on both serotonin and norepinephrine neurotransmitters. It is not the only antidepressant to do this, but SNRIs are a smaller class of drugs than those that just effect serotonin alone (like Prozac). (Although admittedly, there seems to be a suspicious number of SNRI antidepressants in development.)

Pristiq and Effexor Are Almost the Same Drug

What you might not know, is the same company that makes the drug Pristiq (Wyeth) also makes Effexor, which is an almost identical antidepressant, and Effexor has recently become available in generic form (Venlafaxine). Pristiq, O-desmethylvenlafaxine, is actually the main metabolite of Effexor, venlafaxine hydrochloride.

Should We Ignore Pristiq Because We Have Effexor?

This means that if you take Effexor, your body breaks it down into Pristiq and other chemicals. Yes, Pristiq and Effexor are almost the same drug.

So Pristiq is the Same Drug as Effexor?

For this reason, some people say Pristiq is nothing but a “patent extender”. In other words, Wyeth’s patent ran out on one drug (Effexor), so they patented another, almost identical, antidepressant (Pristiq) to keep up their profits.

This, is probably true. If I were a company exec, I would understand that this is an easy way to make money.

And some doctors are claiming that Pristiq should simply be “forgotten about“.

No, Pristiq Is Not the Same Antidepressant as Effexor

The thing is, they are not the same drug. A metabolite is not the same this as the initial compound. When you take Effexor your body metabolizes it into Pristiq and other stuff. That “other stuff” might be good for you, or it might not. It depends on who you are. We all have different needs and chemistries.

Pristiq Has Fewer Side Effects Than Effexor?

But what I think can’t be argued is the fact Pristiq has to, by definition, have fewer side effects on the whole than Effexor. For an individual this may or may not be true, but overall it has to be because Effexor contains more compounds. That’s just logic. (It’s also logical to assume less withdrawal effects too.)

People May Respond or Tolerate Pristiq Where They Didn’t Effexor

Regardless though, even if these two antidepressants are very similar, some people will respond to Pristiq that did not respond to Effexor or could not tolerate the side effects of Effexor. This is a certainty. We, and mood disorders, are all so different that it is obviously true some people will have this response. [push]Quite frankly, Effexor has a lot of side effects and withdrawal issues associated with it, so it wouldn’t surprise me if even a slightly cleaner version would be better tolerated.[/push]

And most importantly, if you and your mental illness fall into the category of people who are helped by Pristiq, who were not helped with Effexor, you really don’t give a shit about patents, metabolites, profits, or self-righteous doctors. You just care you’re being helped. You just care you’re less depressed. And that’s really all you and your doctor should care about. Let doctors be concerned about drug politics on their own time.

Pristiq Will Help Some (Probably Intractably Depressed) People

And that group of people is precisely why doctors should not forget about Pristiq, or any other drug. Humans are unique and many of us depressed/bipolar/other are very difficult to treat, and removing tools from a psychiatrist’s tool belt just because they upset some self-righteous doctor’s situationally convenient morals, is ridiculous.

Is the pharmaceutical company just looking for profits? Yes, of course they are. Is there first concern helping people? No, it probably isn’t. Are the research numbers on Pristiq stunning? Not really. But if you’re in the group of people helped by this antidepressant, you don’t care.

Those of us who have been in treatment for a mental illness for a while know that it’s all a crap shoot anyway, so why take away an option that might get you better? It’s just a stupid thing to do.


Note #1: All that being said, if you’re successful on Effexor, don’t just switch to Pristiq, those other chemicals in Effexor might be the ones helping you. No one can predict whether you’ll have the same reaction to Pristiq. If something is working – don’t mess with it!

Note #2: I’m not endorsing either drug here, just suggesting not ruling them out.

Note #3: Pristiq isn’t my favorite medication. It has absolutely brutal withdrawal symptoms that (for me) kick in within two hours of expected dosing time. I gather this also happens with Effexor, and Effexor’s withdrawal effects tend to be even worse.

Antidepressant Comparison: Pristiq Vs. Effexor


About Natasha Tracy

Natasha Tracy is an award-winning writer, speaker and consultant from the Pacific Northwest. She has been living with bipolar disorder for 18 years and has written more than 1000 articles on the subject.

Natasha’s New Book

Find more of Natasha’s work in her new book: Lost Marbles: Insights into My Life with Depression & Bipolar. Media inquiries can be emailed here.

  1. First of all, thank you for your thoughts. You are correct, for those who are having difficulty finding a drug to make them feel better, drug company policies don’t matter, all that matters is getting better.

    Second, you’ve got a typo in your HTML. Take a look at this paragraph:

    “This is a certainty. We, and mood disorders, are all so different that it is obviously true some people will have this response. [push]Quite frankly, Effexor has a lot of side effects and withdrawal issues associated with it, so it wouldn’t surprise me if even a slightly cleaner version would be better tolerated.[/push]”

    Just an fyi; you can’t fix something if you don’t know it’s there :-)

  2. I was on Pristiq and it worked great. No panic attacks, anxiety about crowds was mostly gone. Then Obama Care came along and decided they weren’t going to pay for it. I was switched to Effexor. I constantly have a mild headache nausea now. Losing weight is a nice side effect but i don’t recommend doing it this way. If I don’t take the Effexor on time my head gets all weird feeling and it ruins my whole day.
    My doctor just had me do a DNA swab to see how I metabolize meds. If it shows that Pristiq is better then the insurance will have to let me switch back.

  3. You’re absolutely right that Pristiq and Effexor are not the same. I’m deficient in CYP2D6 enzymes (genetics), and of almost all the antidepressants out there, Pristiq is the only one my liver can metabolize.

  4. Iv been on (side)-Effects-or 37.5 mg for only 4 days ,and the first day took it at 8 am and by 12pm i had thee worst anxiety attack ever,then day 2 was a little less day 3 was tired ,dragging and anxiety ,day 4 i called doctor and he said to take 75mg at night ,but to be honest i dont want to take it any more i just know this drug is NOT going to work for me if im having these effects after only 4 days ,ANY ADVICE ? ,I know every body is different when it comes to chemical reactions to drugs ,but i just dont like the way it makes me feel ,and since iv only been on 37.5 for 4 days ,does anyone think ill have withdraws ,i would think not due to the fact that i haven’t really built up a blood level ,but this drug scares me from all the post`s iv been reading .

  5. I have taken Pristiq since it came on the market. Before that I was taking Effexor XR for as many years as it had been out. I was at 225mg of Effector and have been on Pristiq 100mg for many years. This year, new insurance with $3600.00 deductible, so since Pristiq will now cost me $250.00 a month, which is out of the question for me, I will have to switch back. I took my last Pristiq night before last, nothing last night and tonight first night of generic Effexor 225mg. I am a nervous wreck about the switch. Didn’t know what else to do. Any input would be appreciated.

  6. Just stumbled across this blog today. I’ve been on Pristiq for about 3 years I guess. In January, my prescription insurance coverage changed and my out of pocket went from about $15 to almost $300 for that script. As we’re in the middle of a really rough financial time, I am just unable to pay that kind of money…after talking with my doctor, I’ve been switched to 75 Mg of Effexor. I was 3 days with nothing and have had only 1 dose of the Effexor. I haven’t experienced any symptons of withdrawal from the Pristiq nor do I feel any different with the Effexor (I know, I’ve only taken one dose).

    Should I expect any serious change? I was SO freaked out about not having anything after reading all the horror stories of the Pristiq wthdrawals…


  7. I have been on a low dose of Effexor (75 mg) for about a year. I just ordered a refill by mail, and I got a bottle of pristine 50 mg instead. No consultation, no weening, nothing. Should I be concerned?? I started taking this following menopause, if that matters.

  8. I have tried a lot of things for anxiety/depression. I had been on Effexor for 6 years and wanted to try Pristiq because of all the hype about it being a cleaner drug and having less side effects. I really had no problem with withdrawals as I went straight to Pristiq from Effexor. Now I feed like 100mg of Pristiq really doesn’t do much for me. So, after all that I have decided to switch back to Effexor of which I was on 300mg a day. I must be the only person out there that benefited positively from the extra components in Effexor, that don’t exist in Pristiq!

  9. On lamotirgine with effexor. The OLNY combo that ever worked for me – no persistent anger or depression. After a few years on effexor I decided that I “plateaued” and decided to switch to Wellbutrin. BIG mistake. Now I am angry and short tempered most of the time and struggle with persistent nausea and dizziness. I lost ten pounds but I think that I’d rather be overweight than feel like this. May add more lamotirgine and if that doesn’t work back to effexor. Withdrawal aside, if it ain’t broke, don’t fix it.

  10. I’ve been taking pritiq for about 3 years, I have really bad panic attacks and after so much trial and error with medicines and docs, this seems to have helped!
    I have tried effexor, because my medical doesnt cover pristiq, but I had lots a bad side effects.
    I’m 20 and I hope I can eventually get rid of pills for good!

  11. Hi. I was on Effexor for quite a few years. Had issues with weight gain, but hadn’t had panic attacks for over 8mth. So stupid me decided I wanted to wein off. Dr asked me to try Pristiq. I am on 100mlg a day. I still get too many panick attacks and went up again weight wise. I started to feel like I cant get my breath sometimes and yawn an aweful lot which makes me hyperventilate. Which kicks in a panick attack. I am calling my dr. today to either increase the dosage or go back on effexor. I think I am “thinking” about my breathing too much and psyching myself out. Didn’t have any problems other than weight with effexor.

  12. Took Effexor about 15 years ago. It worked *great* for my symptoms. Nothing else had (and I’ve tried a bunch of them over the years). Unfortunately, my blood pressure skyrocketed to something like 200/120, so had to say “goodbye” to it. That two or three weeks of withdrawal symptoms was no picnic, but I’m very much “anti” stroke symptoms. :-)

    The next ten years or so of trying various other drugs yielded no (significant) positive results. Read about and considered trying Cymbalta, but the testimonials I read about that one scared me off.

    I’m now doing quite well on Pristiq (60% as well as on Effexor?) and, happily, have normal blood pressure. Those “ickies” when late on the daily dose can be interesting, but, as others have said, remind one that the dose might have been forgotten. BTW, multiply those “ickies” by some factor to get a feel for what the cold turkey withdrawal from the Effexor was like. Reminds of that Steven Wright (I think) line about “you know what it feels like when you’ve tipped yer chair back a little too far and it almost tips over – but you barely catch yerself? That’s what I feel like all the time. ” :-) It likely would have been a little less bad had I known for sure that it would go away after about two and a half weeks. :-)

    So, a lot of what I’ve read in yer article and the comments sounds pretty good. I especially endorse the idea of continuing to try different meds until you find something that (hopefully) works. Depression really sucks.

    Oh, and unless you have a very specific situation (oddly, as in “causing” something), use “affect” rather than “effect” when using the verb. :-) I’m sure most of us can also utilize “affect” in the noun form, considering it’s use in the psychological realm. :-)

  13. I was on Effector and it was brutal. Then the
    withdrawal was hell I wanted.
    to die. Then Pristiq made my issues worse. Neither of them were any good. On lamatical now it stablizes the mood. Have to deal with the residuael.on my own

    • Hi Sheryl,

      If you’re bipolar, lamotrigine (Lamictal) makes more sense than either antidepressant anyway. Plus, there is always the option of adding and antidepressant to the lamotrigine if you need to.

      Good luck.

      – Natasha Tracy

    • I had the same terrible reaction on both drugs. I seriously questioned why my doctor would put me on Pristiq when I reacted so badly to effexor xr in the first place.

  14. Thank u for the great information. I take effexor and it’s ok though I’m only toleratimg a mid size dose. It is great to have this info.

  15. i have been transitioning from effexor to pristiq and went through a really bad 2and 1/2 weeks. Now i am feeling better and noticed something interesting. Before changing drugs, my fasting blood sugar was 136. Yesterday it was “LO” meaning I needed to get some sugar in me to feel OK. This am it was 74. It has never been lower than 100 since i was diagnosed with type 2 diabetes about 5 yrs. ago. I haven’t taken any meds for diabetes for at least 2 years. Effexor causes diabetes?

    • The idea that effexor can cause diabetes is rather disturbing as I’m classed as high risk (mum, maternal aunt and grandmother all have type 2)

      • Hi Tracey,

        Please see my previous comment.

        Keep in mind that diabetes is a _rare_ side effect (fewer than 1/1000 people) but it _could_ happen so certainly you are wise to keep an eye on your blood sugar.

        As I mentioned, diabetes is not listed as a side effect to Pristiq, which might be an option for you.

        – Natasha Tracy

  16. I couldn’t agree more about not ruling them out. It certainly is a case of trial and error. Trying different doses and meds until you find the one dose or combination of meds that seem to work best. We need all the options available.
    I had been on Effexor for two years and was slowly (very slowly) tapered off and put on Pristiq. I found both to have awful withdrawal symptoms although Effexor was definitely the worst. It could be seen as a positive (to doctors/family/friends etc) as it makes you less likely to stop taking it because of how awful it is when you forget to take your dose even just by a few hours.
    I’ve been on Pristiq for over two years now. The combination of Pristiq and Lithium are what work for me now and it’s taken years of trial and error with meds and doses to get to this point!

  17. I’m on Effexor and the ickies do kick in so soon. I forget to take them at my usual time (I’m trying to have a life here lol) and within an hour or so I feel so bad. I guess I’m not likely to forget them completely though

    • Hi Tracey,

      I’ve had that exact experience with Pristiq. And the funny thing is I’ll get the “ickies” and not remember that I forgot the pill. Until the ickies are really bad and then it’s impossible not to realize it.

      So yes, can’t forget completely.

      – Natasha Tracy

      • I was taking cymbalta (a cousin of effexor apparently) for around 4 yrs. In the last yr of taking it I was experiencing stomach pains (like someone had actually crawled inside my stomach and beat the hell out of it) and always had severe restless legs (which i put down to a calcium/magnesium deficency). After I had decided enough was enough, my dr weened me onto pristiq and took me off cymbalta. The withdrawals and side effects were minimal for me, perhaps to do with the slow weaning process. Usually, if I had forgotten to take the cymbalta at the usual time I would have major dt’s, light headed and dizzy and nauseous.

        So far so good on the pristiq, even tho it’s only early days. Can’t say my mood has changed from when I was taking cymbalta, much the same really ><. But at least I don't have awful stomach pains and the like. End of the day, pharmacutical companies wanna make money, it's up to our dr's and ourselves to get the right medication that works for each person. It effects everyone differently, even those with the same conditions. It's painful having to go thru the process of trial and error but in the end it can be worth it.

        • Hi Jazz,

          You’re absolutely right that pharmaceutical companies just want to make money and it’s our job to find what’s right for us. It’s a tough job, but we are charged with doing it. And yes, in the end it is worth it.

          Glad you’re not having the horrible stomach pains any more. New meds – good for something :)

          – Natasha Tracy