Posted by MB on July 13, 2001, at 13:37:14
In reply to Re: Weight gain and SSRIs » MB, posted by Elizabeth on July 12, 2001, at 19:02:14
> > Doesn't Meridia work on Serotonin?
>
> It's a serotonin-norepinephrine reuptake inhibitor, just like Effexor. It even resembles venlafaxine structurally There's no reason it wouldn't be just as good an AD as EffexorThe excuse I've heard for it's not being marketed as an AD is the half-life issue and consequently frequent dosing schedule (or something like that). But, if they can solve that problem with Wellbutrin by making SR, they could have solved it with sibutramine also (couldn't they have?)
> it wasn't marketed for this indication because the market for ADs was already saturated.
That sounds more plausible.
> But in early literature on sibutramine, it's referred to as an "antidepressant," not as a weight loss aid. (I would bet that it's a crappy diet pill, BTW. < g >) =Well, there must be something more to it; it's scheduled as a class IV, isn't it?
> > It mentioned antagonism of 5HT-2c as a possible mechanism for neuroleptic weight gain.
>
> Well, they're strong antihistamines too (hence the sedation). Do "typical" antipsychotics block the 5HT-2c receptor? Or is weight gain from these drugs attributed solely to the H1 blocking?The typicals are potent H-1 blockers, yet they don't seem to carry the 30% risk of 20% weight gain that the typicals carry (especially clozapine). I think the blockade of 5HT-2c receptors in the striatum is one of the things that makes the atypicals different. Blockade at these sites increases dopaminergic activity in the striatum, hence the fewer incidences of tardive dyskinesia...or so it has been hypothesized.
> I'll take a look at that site.
>
> > in fact, I think the guy stated that this was the puted mechanism of Meridia.
>
> (You mean "putative," right?" I'm skeptical of that, since no other mechanisms have been IDed for Meridia besides monoamine reuptake inhibition, AFAIK.)Uh...yeah...putative. Sometimes I accidently make up new words (LOL!) When the guy mentioned 5HT-2c interaction as a possible mechanism for Meridia's anorexigenic effects, I think he was referring to the indirect *stimulation* of these sites by monoamine (in this case serotonin) reuptake inhibition. I was a little ambiguous about that. I'm sure the indirect NE-a1 activation (from NE reuptake inhibition) might also contributes to the anorexigenic effects.
> BTW, SSRIs and Effexor don't "make people fat" across the board, and it's not clear that it's even a majority side effect. The people who gain weight are the ones who complain. As I mentioned, I took Prozac for between two and three years, and I didn't gain weight beyond my baseline weight *or* regain the weight that I'd lost while depressed.
Right, and there's also the theory that it's the alleviation of depression (and it's comorbid anorexia) that is behind the SSRI-weight correlation (and that the correlation is not directly causative). Anecdotally, I eat more when depressed, and still gained weight on SSRIs. Maybe, at some point, we just have to admit that nobody really knows?
> > I gorge myself when I'm dysthymic or anxious, but I barely eat when i'm *really* depressed.
>
> Perhaps you have two different problems going on at the same time. I think this might be what's happening with me (although I have fewer and subtler "atypical" symptoms).
>
> > That would go against an atypical dx, wouldn't it?
>
> Yes, but the subtypes haven't been defined perfectly yet. Constructing subtypes based on medication response is simply the most pragmatic way to go about doing clinical research until we have a better understanding of how the brain works (and how it malfunctions).I'm starting to think that for a classification system to truely be accurate, there would need to be a subtype for every ill individual! < g > Like you said, it seems that the best that doctors can do is to classify based on medication response. So the question that begs asking is whether these subtypes are really discrete disorders, or whether there is really a multiaxial spectrum upon which every individual falls (I assume that the axial nexus would be "normalcy," whatever *that* is).
> > Yeah, I gained about 30lbs while taking Paxil. I've gotten my body fat back down to about where it was before I started, but my body is just stockier and heavier...shaped differntly...it's like the Paxil just permanently changed my body type, or something. Or, maybe it's just hitting 30 yrs old that did it.
>
> People do tend to get heavier as they age. I easily lost all the weight I gained on Nardil -- I call it "the depression diet" -- but because I switched directly to Parnate, the weight from Marplan hasn't gone away completely. Losing weight is *hard*.
>
> -elizabeth(losing weight is hard)
Amen to that!Peace,
MB
poster:MB
thread:59947
URL: http://www.dr-bob.org/babble/20010708/msgs/70010.html