What You Should Know About Prozac and Other Antidepressant Meds, Part 2, SNRI's

We had talked about SSRIs with brand names such as Prozac, Lexapro, Celexa, Zoloft, Paxil and Luvox.  

In this post, we talk about another common class of antidepressants, SNRI's with popular brands such as  Effexor, Effexor XR, Cymbalta and Pristiq. 

SNRI's are Serotonin Norepinephrine Reuptake Inhibitors so they work on two neurotransmiters--serotonin or norepinephrine (also called noradrenaline) instead of just one as it is with SSRI's.

SNRI's did not score "highly" compared to other SSRI's for depression based on a meta-analysis published in Lancet (which rated Lexapro and Zoloft highly).  BUT--SNRI's are particularly useful when it comes to anxiety and panic disorder.  SNRI's also often work faster than SSRI's (which can take weeks) and they can relieve depression symptoms within a week for many.  Effexor in particular can start to work within 3-4 days.

Con's:
1. Like SSRI's, most SNRI's can decrease libido and make it more difficult to achieve orgasm. This side effect tends to show up when the dose of the antidepressant goes up; also, over time, this side effect may decrease. If this side effect is unacceptable, one strategy would be to switch to another antidepressant which is known to have much less libido/orgasm side effect, such as Wellbutrin.   Sometimes, it's also possible to decrease the dose of the SNRI and add a small dose of Wellbutrin so that someone can still get relief from depression with less side effects.

Unfortunately, SNRI's like SSRI's can also cause weight gain in some. The most notorious "weight gainer" is Paxil but it can also happen in varying degrees with other antidepressants. Not everyone who starts an antidepressant gains weight.

2. Many SNRI's can have more withdrawal symptoms versus SSRI's when someone is deciding to discontinue their medication for whatever reason.  The most notorious is Effexor (second is probably Cymbalta) and some of the withdrawal symptoms include nausea, dizziness, anxiety, feeling an "electric shock,"  feeling "zaps," and other odd sensations.

There are several ways to address this: The first
is to do a "slow taper" where one decreases the dose of the medication slowly in small increments over a longer period of time--this allows the body to adjust.  The other strategy is to switch someone momentarily to an antidepressant (typically an SSRI such as Lexapro and Prozac) that has a "smoother" profile in terms of discontinuing and then taper off from this smoother antidepressant.

Pro's:
1. SNRI's may be better for persons with both depression and anxiety--as SNRI's seem to work better for anxiety than SSRI's.

2. If someone is not getting much relief from SSRI's--such as Lexapro, Zoloft, Celexa, Prozac--then it is very reasonable to try SNRI's because SNRI's work on different neurotransmitter systems.

3. SNRI's work faster, often some relief starts to kick in within a week. For SSRI's, it can take weeks. However, I have to say that in practice, SSRI's can also work within a week and this is something that is observed by other doctors as well, and what is most important is to find a "good match" addressing both the symptom picture of the patient, as well as concerns with side effects.  Weight gain is one side effect I really dislike with patients, so I do avoid Paxil a lot.

Also, it is important to work with a doctor with an "end game" in mind. What I mean by this is that they are not only thinking of antidepressants as THE treatment for your depression.  These antidepressants should be thought of as a "bridge" only until the doctor-patient is able to find a more long-term and more sustainable treatment plan for the patient.

I want to encourage patients that many patients have been able to get off antidepressants with the proper support and guidance. If someone has been on an antidepressant for a long time, it may take longer and with more work but it is possible. Also, as described above, some antidepressants may be more difficult to discontinue, but it is doable.

Find out about SSRI's and tricyclic antidepressants here.