Reason For One SSRI Over Another?

[187502]

I recently saw a patient, 41 y/o SWM with a history of MDD/Dysthymia/GAD/Panic Disorder that is mostly in remission on paroxetine, 60mg QD (patient indicates some anxiety during particularly stressful situations, but not overwhelming, and can be tolerated). Previous medication, Lexapro, didn't provide any relief and actually caused new body-focused anxiety that the patient denied experiencing at any previous time.

C/C for the visit was that while the patient is happy to be in remission on paroxetine he indicated significant of side-effects (GI disturbance, occasional transient dizziness, significant sexual side-effects, etc...). He also indicated very minor activation of obsessive/compulsive behavior on the paroxetine that he has never experience before, but was not particularly bothered by it since it mostly involved organizational behaviors and organization was apparently something he has always had difficulties with. He indicated that he spoke with his pharmacist and the pharmacist indicated that he should consider switching to sertraline from paroxetine since it should work just as well and tends to have fewer side effects. As a result of the consultation with the pharmacist he is eager to give sertraline a try.

From what I have read on the topic, I haven't seen anything that indicates that one SSRI should be any more or less effective than any other when it comes to treatment of the aforementioned pathologies (except that sertraline is not approved for GAD while paroxetine is), and from the prescribing information for sertraline I don't see that the side effect profile is any different than that for paroxetine.

However, I know that papers and practice are typically two different things, so I figured I would ask the experts. For his particular basket of pathologies, as well as his response to Lexapro and paroxetine, is there any reason to believe that sertraline will be at least as effective as paroxetine for treatment with fewer side effects?

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[whopper]

There are many reasons to offer one SSRI over another.

1)Price. 3 SSRIs are now generic & have a $4/month, $10/3 month price.
Citalopram, Paroxtine & Fluoxetine are in this category.

While Sertraline is available as a generic, its still much pricier than $4 a month

2) side effects. Lexapro out of all the SSRIs has the least amount of side effects & the least amount of interactions with other meds & uses the least amount of liver metabolic activity. This makes it a first line choice for a patient in need of an SSRI but also on multiple meds, poor health & a compromised liver.

Citalopram though is a close 2nd. While it is not as clean as Lexapro the difference is not much. In fact in studies only a few percentage points in difference in the amount of side effects. For that reason, I still give citalopram as a first choice, even if patients that can easily afford a non-generic. Why give the more expensive med if its not superior?

Which meds are the dirtiest? Paroxetine & Fluoxetine.

Paroxetine out of all the SSRIs causes the most amount of weight gain due to its stronger antihistaminic & anticholinergic side effects.

3) half life. The shorter the half life--the higher the chance of discontinuation syndrome. Paroxetine has a t1/2 of less than 24 hrs. This makes it much more likely to give discontinuation syndrome. Out of all I've ever prescribed--only 2 have given DC syndrome to the point where my patients had very frustrating problems getting off the med--Paxil & Effexor (which also has a t1/2 less than 24 hrs).

4) FDA approval. While this IMHO is not a good reason to exclude some SSRIs, FDA approval does give protection. All SSRIs should be equally efficacious despite the disorder, given that its administered at the appropriate dose. Despite this, several SSRIs, mostly for political & business reasons do not have FDA approvals on all the disorders SSRIs can be used for.

5) Know the specific qualities of the med & see how much if correlates with what your patient needs. This takes a lot of experience before you start noticing the more subtle differences between these meds. For example, Fluoxetine is a mild stimulant, in fact it is chemically structurally similar to an amphetamine.

A stimulant used to treat a patient with an anxiety disorder can actually make things somewhat worse. Patients given fluoxetine for an anxiety disorder, if that dose is raised too quickly can worsen their anxiety, which as you probably know is highly beta adrenergically driven. Also, SSRIs don't cause their benefit for several days after its administered.

Paroxetine-often times causes sedation & weight gain
Sertraline-several patients complain it gives them a feeling as if a wet towel is wrapped around their head.

This specific point also favors lexapro & citalopram since both are the cleanest meds with the least amount of side effects.

As a medstudent, I don't expect you to see much difference between the SSRIs. Its too much info for someone at your stage, but should you go into psychiatry or Family Practice, you really need to know your SSRIs.

 

[OldPsychDoc]

What he said---mostly. Though Lexapro, "clean" as it may be, I've found to also be rather activating in many anxious patients.

 

[187502]

So, based on what you wrote, Sertraline would be worth trying as a substitute for this patient to decrease the side effects he is experiencing from the Paroxetine?

 

[Hurricane]

So, based on what you wrote, Sertraline would be worth trying as a substitute for this patient to decrease the side effects he is experiencing from the Paroxetine?

The ultimate deciding factor is patient preference. Some patients would find the side effects you described intolerable. Others are so relieved to be in remission that they much prefer the side effects to the risk of relapse if they switch.

If you switch, be sure to document what symptoms were treated with the paxil and what the side effects were. (You should do so whenever you switch meds, because it will help other doctors make decisions in the future.)

 

[TheWowEffect]

While patient preference is very important, you will commonly be treating patients who will say, "Doc, tell me what you recommend and I'll take it." In that scenario, make sure that you have a good and intelligent answer for the patient. You'll do yourself a huge favor and build a reputation for being "a good doctor."

 

[whopper]

While patient preference is very important, you will commonly be treating patients who will say, "Doc, tell me what you recommend and I'll take it." In that scenario, make sure that you have a good and intelligent answer for the patient. You'll do yourself a huge favor and build a reputation for being "a good doctor."

True.

Several patients when you present them with all the differences between the antidepressants, its overkill. Its too much info to take in at once.

Also, managed care doesn't give us as much time as we'd sometimes like to educate patients. I've actually thought of perhaps making little booklets so patients can read them in the waiting room or as a homework assignment (kinda like CBT) on things that can empower them that managed care doesnt' give me enough time to educate them on.

But several will say something to the effect of, "hey doc, you know more about this than I do, you pick". If it comes to that, pick the based on your education & experience is the best for their situation. Again--comes down to side effects & price given that pretty much all the antidepressants are equally efficacious (on the first try).

But, if the patient is already on something that's working, you're taking a risk by switching them, even if you think there's a better antidepressant for them. For some reason, some patients respond to 1 but not another. Remember, equally efficacious doesn't mean they'll all work just as well on all patients. They are equal in terms of efficacy across the population on the first try. Some patients one works, but the other doesn't.

IF you do the switch, from one SSRI that's working to another, you need to be certain the patient understands the benefits vs risks & wants the switch. You should also document why you are doing this. You also need to educate the patient that the new one might not work & call you should he/she start noticing its not working so you can switch them back.

Also, when switching, don't cold turkey stop one & start the other. Gradually taper one down & start low on the other & cross over the course of at least a few weeks.
For myself, I really didn't get to know the different between the SSRIs till about 3-4 months of psychiatry residency (not including the IM rotation), and I didn't start plateauing in on which ones were the best for the given situation until about my 3rd year.

What really got me on the major differences were specific grand rounds where the topic was the differences between the antidepressants, both in effect, metabolism, side effects, & interactions between other meds & diseases. I hate to say it, but if you're a brand new resident, pharm company lectures do yield some good information (though you also have to remember that lecture is part commercial).

One category I didn't throw in was PAIN, and I didn't because the question was SSRIS, not antidepressants in general.

The SNRIs have been found to yield pain benefits. Studies show that norepinephrine reuptake inhibitors reduce chronic pain. For this reason, SNRIs are also used in fibromyalgia (which is often correlated with psychiatric illness) among other disorders. Elavil also has this benefit (even an FDA approval for this) though studies I've seen put the SNRIs as equal efficacy to Elavil, so I figure the SNRI will be a better first line since they have less side effects.-I would consider an SNRI first line over an SSRI, if the patient had chronic pain.

 

[maybepsych]

Thanks Whopper, very informative.