Meridia and antidepressants–Part I and Part II

PART I 

Last week a patient came in with question regarding the use of antidepressants while taking the weight loss drug Meridia.  Seems her family doc took her off the two antidepressants I had her on to treat her depression (Lexapro and Wellbutrin if my memory serves me), and gave her Meridia to treat her weight issue.  While somewhat overweight, this lady was far from obese, so I would not consider this change an emergency.  My patient’s question was . . . “can I still take something to treat my depression?”

In a word . . . “NO”.

At least not with standard antidepressants.  The reason boils down to the mechanism of action.  Frequent fliers on this site will remember that all of the antidepressants increase the levels of one or more of the main neurotransmitters involved in mood.  This includes serotonin, norepinephrine and dopamine.  Most of the antidepressants do this by re-uptake inhibition.  Re-uptake inhibition is the process of blocking the main recycling pathway the body uses to conserve the neurotransmitters after firing them off from one nerve cell to another. Well, it turns out that the mechanism of action of Meridia is also re-uptake inhibition of these neurotranmitters.  Not only does it block re-uptake, it blocks re-uptake of all three neurotransmitters (tho’ the re-uptake of dopamine is much less than that of serotonin and norepinephrine).  The risk here is that the combination of multiple medications that increase serotonin levels puts a patient at risk of something called Serotonin Syndrome which is a potentially deadly physiologic reaction to an over-abundance of serotonin in the brain (look for that in another blarticle).  A reasonable question here is whether or not Meridia can function as an antidepressant since it has a similar mechanism of action as the antidepressants.  My patient certainly did not get profoundly depressed when switched over to Meridia.  By my reading of the information on it, however, there does not seem to be clinical studies showing either benefits or lack of benefits.  The jury is still out.  I suspect that there are studies going on somewhere about this.  Especially since any medication that acts on all three neurotransmitters is like the “Holy Grail” of psychopharmacology . . . a medicine that is triple action (remember Cymbalta’s big claim to fame is that it acts on two receptor systems–norepi and serotonin).

So, for now Ms. H, if you choose to stay on Meridia, you cannot take antidepressants.  We will just have to keep an eye on you and balance the benefits you get from it with the pattern of your mood symptoms which may or may not get worse.

PART II

How unreasonable is it for me to expect that I am consulted or at least INFORMED when another physician changes the medicine I have prescribed for a serious and potentially deadly illness (Major Depression)? My patient has had a very difficult year with a variety of significant stresses.  Her mood disorder is long-standing and has, at times, been quite serious.  The family doc in question did not call and consult me nor inform me that the medication that I thought quite important to this patient was being stopped.  If I went around adjusting medication for blood pressure of diabetes without letting the prescribing physician know, I would be called on the carpet and flogged (figuratively, of course).  Now, I am hopeful that all will go well.  If things do not go well, how much responsibility will this doc take? 

My message to all reading this is as follows:  If you are receiving treatment for a condition by a specialist, make sure that your family doctor communicates with the specialist if he or she makes changes to the medicine prescribed by the specialist.  This is especially true when dramatic changes take place (like stopping a medicine).  There is a reason you are going to a specialist and there is a reason the specialist is a specialist . . . certain conditions are intrinsically more difficult to manage and the input of a specialist can be vitally important.  To take them out of the loop when decisions are being made is to potentially put you at greater risk.

Rant and rave over . . . have a good day.

–Dan Hartman, MD

2 comments to Meridia and antidepressants–Part I and Part II

  • Mark

    Hey there. I have been scouring the web for anything on combinations of Meridia and antidepressants, and I don’t know who to turn to, because I’m in a situation where I will be burned no matter what I do.

    I have a long-standing GP who has always been open to treatment options for my depression, but when it comes to weight, he has always been totally against Meridia or anything like that. So, for the past few years, I sought weight treatment with Meridia at a drop in clinic. It works successfully.

    However, my depression is coming back now, stronger than ever, seeing sick days at work, and I even need a week or two of stress leave. However, I am once again on a round of Meridia. I can’t tell my “real” GP I’ve been taking Meridia because then he will be hesitant to give me the wide variety of treatment options he’s always been open to.

    The drop in GP is running a bunch of blood tests, but when I asked, she said it is not totally out of the question to combine Meridia with certain kinds of antidepressants.

    I have tried the ADs before, but they all didn’t work, and some caused weight gain which was distressing. I’ve tried Prozac, Serzone, Celexa, Effexor, Remeron and Wellbutrin.

    I am wondering how off her claim is, that I could combine, what if I tried one of the older-style MAOIs or something like that?

    If you have any insight… it would be appreciated…

  • Mark–
    Sorry dude . . . my answer remains the same. Combining meridia with antidepressants is potentially very hazardous so it cannot be considered safe. I would give a double NO NO to using meridia with an MAOI. Given the mechanisms of action of the two meds, the likelihood of a catastrophic increase in your blood pressure is too high. DON’T DO IT.

    I do find that patients come to me with odd combinations of antidepressants (eg, Zoloft and Effexor together). This is, in effect, the same as adding meridia to an antidepressant. When someone comes in with this combination . . . I change it. It makes no sense and it is potentially dangerous. So is the combo of meridia with an antidepressant. I just won’t do it.

    If your set on sticking with the meridia, you might try Lamictal. While mostly used for Bipolar depression, it is also being used to treat unipolar depression. That does not interact with meridia (as far as I can see). Rather than taking meds from various docs and not being completely honest with any of them, I suggest you find someone you trust and work with them. Doesn’t mean you will like all the answers given, but if you trust and respect the judgement of the doc you are working with, maybe what needs to change is not the meds, but your approach to your various conditions.

    –DH MD