Effexor XR vs Pristiq

[firedoor]

Thoughts? Experiences?

My primary inquiry regards effectiveness, though I hope this thread can address the full range of differences and similarities.

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[OldPsychDoc]

Thoughts? Experiences?

My primary inquiry regards effectiveness, though I hope this thread can address the full range of differences and similarities.

Two words: Patent Extension.

 

[WhoisJohnGalt]

Two words: Patent Extension.

I really hate Pristiq and Lexapro. Many of my attendings use them but I don't understand why.

 

[billypilgrim37]

Pristiq is an excellent medicine if you have trouble counting by 75's.

 

[whopper]

Per data, Pristiq and Effexor have more side effects than SSRIs such as Lexapro and Citalopram. While Lexapro is a tradename med it's actually relatively cheap though Citalopram is way way way cheaper.

Citalopram: $4 a month for 30 pills.
Lexapro: 5 mg (30 ea): $107.99 10 mg (30 ea): $118.99 20 mg (30 ea): $118.99
Effexor XR: 37.5 mg (30 ea): $129.99 75 mg (90 ea): $409.99 150 mg (30 ea): $159.99
Venlafaxine ER: 225 mg (30 ea): $256.98
Pristiq: 50 mg (30 ea): $141.99 100 mg (30 ea): $146.99

Now that said, I haven't had any cases, at least so far, where Pristiq seemed to reveal anything special to the degree where it was preferrable over Effexor.

Oddly, I've had cases where a patient was able to tolerate Lexapro or Citalopram but not the other. IMHO the only thing that can explain this is the medium holding the med in the pill was somehow causing a problem.

I find little reason to give Effexor or Pristiq as a firstline med. There is no cheap version of it and it has more side effects to a population vs. Citalopram.

Many of my attendings use them but I don't understand why.

Some doctors I've noticed don't seem to give a damn about the price. This is a shame because if all doctors gave out cheaper alternatives that worked just as well, we could put a huge dent in the cost of medical care. Others are just plain idiots or sold to the drug reps.

I got a bunch of the residents under me, when I was a chief resident, to give out Citalopram instead of Lexapro. An attending mentioned that he was somewhat upset with this because I must have been somehow converted by a Citalopram drug rep. Hmm, it's a $4 generic. There are no reps for it. It was saving the system a heck of a lot more money vs. giving out something > 20x the price. He didn't know that. He was completely oblivious to the price of meds (among several other things). All he saw was a bunch of residents give out one med.

Not suprisingly, whenever he got a patient that stopped Lexapro because they couldn't afford it, he just put them right back on it in the hospital and discharged them on it.

 

[Atilla]

If i have to go to an SNRI, I will go to Effexor first. If it works but patients are having side effects, I switch to Pristiq and ~50% of the cases the the side effects ( drowsiness, Sexual SE) do go away.

I am speaking from personal experience and have no studies to back it up.

 

[whopper]

I can see that being the case. While Pristiq is similar to Effexor, it's on the order of a friendlier version of it.

You have no studies to back it up, but such is where studies can start. Many clinical doctors see these things but don't go any further.

On the same notion, I've seen some people have side effects to Risperdal, but those same people don't have side effects or they have less on Invega. I still give out the cheaper stuff first just in case. If they can tolerate it fine. If there was a benefit, but there were side effects, then consider the more expensive stuff that's similar to it, or another med.

 

[firedoor]

I'm totally on board with using cheap agents.

That said, there are two possible advantages to Pristiq over Effexor which I'm curious about:

1. Less hypertension risk?
2. Less withdrawal symptoms?

Are these accurate?

Lastly, according to my archenemy Dr. Daniel Carlat, "In the U.S. study, Pristiq decreased the HamD by only 2 points (-11.5 vs. -9.5 for placebo), and in the European study, the differences was 2.5 points. And for the higher 100 mg dose, there was no difference between drug and placebo for U.S. patients". And, "At least with Effexor XR, when you keep increasing the dose, efficacy improves, meaning it actually has an efficacy advantage over Pristiq, because when you increase the dose of Pristiq, you actually lose efficacy, according to the U.S. study data".

Hmmm...

 

[whopper]

Pristiq has a longer half life. Discontinuation syndrome is largely based on short half-lives. The shorter the half life, the more likely the person will experience discontinuation.

Though Pristiq still has a very short half-life. Per all the SNRIs and SSRIs, Paxil and Effexor have the shortest, and not surprisingly, the only people I've seen who've had discontinuation syndrome even when the tapered their meds down slowly were from those meds.

I have seen discontinuation syndrome with other meds but only when the person was on a high dosage and they stopped cold turkey (that we know you are not supposed to do.). I've never seen discontinuation from Prozac that has a half life of several days.

Pristiq: urine 64-69% (45% unchanged); Half-life: 11h, 13-14h (mod-severe hepatic impairment), 13-18h (mild-severe renal impairment), 23h (ESRD)

Effexor: urine 87% (5% unchanged); Half-life: 5h (venlafaxine), 11h (O-desmethylvenlafaxine)

The only time I had a patient on Pristiq, she was on it because she had gastric bypass surgery and had to be on a tablet, and I wasn't the one who started it. Some meds come in capsules. It didn't work. I had to put her on Prozac 20 mg tabs because higher dosages come in capsules. The idiot Humana preauthorization made me spend almost half an hour to get a freaking $4 med approved. They kept telling me to give her the capsules because she needed 80 mg Qdaily of the stuff. There's a reason why M.D.s, not accountants are supposed to figure out what med to give.

 

[firedoor]

What is the relative risk of hypertension for Pristiq vs. Effexor XR? I've heard talk of 400 mg of Pristiq with no appreciable blood pressure concerns. Is this substantiated?