Posted by jay on August 21, 2003, at 16:19:25
I have found a fair explanation of why many get Prozac-induced weight gain so easily. I've posted the article below, so scroll down for it. I am now using Ginko as it has helped me lose weight or stabalize it in the past, even if it did little for sexual function. I am posting this in hopes it can help others..and I also thank you all for your kind support. As for my low-carb, protein shake, even eating excellent and below 1200 calories a day, I put on up to 10 pounds in 4 days! This is *not* a mistake, and used more than one scale to weigh. (This is not just after meals...or anything like that. My Mom had problems in the past with a Soy-based protein drink also, putting on weight.) Plus, I have regular exercise 7 days a week! I *refuse* to give up my Prozac for this, as well as my Zyprexa (I use this because it's longer lasting and smoother for me than Risperdal.)
Anyhow..here is the article on Prozac, and weight gain with many psychotropic drugs:
------http://www.psychiatrist.com/pcc/brainstorm/br591003.htm
From the Clinical Neuroscience Research Center in San Diego and the Department of Psychiatry at the University of California San Diego.
Drugs That Bind to "Thin" Receptors
The SSRIs indirectly activate the 5-HT2C receptor by raising synaptic levels of serotonin,1,2 resulting in many patients reporting short-term weight loss, but many reporting weight gain with longer-term treatment.6 Fluoxetine and norfluoxetine also have direct agonist actions at 5-HT2C receptors and often produce short-term weight loss but a long-term weight gain.7 A metabolite of nefazodone, m-CPP, is also an agonist at 5-HT2C receptors, possibly explaining why there are relatively few reports of weight gain with nefazodone.2,6
Bupropion has prodopaminergic and pronoradrenergic actions,5 which could explain why there are few reports of weight gain with long-term treatment with this agent and numerous reports of short-term weight loss. Another drug with pronoradrenergic actions as well as proserotonergic actions is the most recently marketed appetite suppressant sibutramine.8 As with all pronoradrenergic agents, weight loss could potentially occur via 2 mechanisms1: central, where activation of CNS adrenergic receptors reduces appetite, and peripheral, where activation of beta3-adrenergic receptors on adipose cells causes them to break down fat and increase body metabolism.1,3,6,8
Nicotine is a drug of abuse that reduces appetite, causes weight loss, and is notorious for causing weight gain once an individual stops smoking. It produces nicotinic stimulation of receptors on dopamine neurons, causing release of central dopamine5 and reduction of appetite.
Classical anorectics are all releasers of dopamine and indirect stimulators of D2 receptors.1,2,5 These include phentermine, diethylpropion, amphetamines, and others. Unfortunately, these agents are famous not only for inducing rapid tolerance to the appetite-suppressing actions, but also for causing abuse when administered long-term.5
Drugs That Bind to "Fat" Receptors
Several antidepressants and antipsychotics are associated with weight gain.1,6 Tricyclic antidepressants and mirtazapine block H1 receptors.5 All antipsychotics block D2 receptors to some degree,5 many having an unfortunate triple effect that includes blockade of 3 receptors (D2, H1, and 5-HT2C) at the same time5a formula that can explain in part the all too common incidence of obesity and weight gain in patients taking not only conventional antipsychotics, but especially the newer atypical antipsychotics.Fighting or Switching
To manage psychotropic drug-induced weight gain, one can either fight or switch. Switching to an agent that lacks interactions with receptors that lead to weight gain is perhaps most attractive, but not always feasible. All available intraclass alternates may share the same undesirable properties. In this case, however, empiric clinical observations suggest that some patients can nevertheless have very different responses to drugs that share the same mechanism, so a within-class switch may be worth a try. This may be particularly true for the typical antipsychotics loxapine and molindone, which seem to produce the least amount of weight gain among the neuroleptics. Sometimes weight gain in a patient receiving one of the atypical antipsychotics can be strikingly different from that associated with another atypical.In other cases, the possibility of a clinical relapse is just too great a risk to justify discontinuation of the currently effective agent. In that case, clinical anecdotes and scientific rationale are the psychiatrist's best hope. Although essentially no controlled studies suggest that combining the offending drug with another agent with an opposing pharmacologic mechanism can be useful, some combinations may work, e.g., combining bupropion, SSRIs, venlafaxine, or stimulants with mirtazapine.9 Since psychotic patients should not take stimulants, treatment with SSRIs, bupropion, venlafaxine, and, in some cases, low doses of direct-acting D2 agonists such as cabergoline or bromocriptine might be helpful for patients with weight gain who are taking antipsychotics.
Hopefully, as the pharmacologic mechanisms of weight gain become better understood, well-designed studies geared toward the development of guidelines for managing weight gain by using combinations of psychotropic drugs will be forthcoming. u
REFERENCES
1. Stahl SM. Neuropharmacology of obesity: my receptors made me do it [Brainstorms]. J Clin Psychiatry 1998;59:447-448
2. Curzon G, Gibson EL, Oluyomi AD. Appetite suppression by commonly used drugs depends on 5HT receptors but not on 5HT availability. Trends Pharmacol Sci 1998;18:21-25
3. Strosberg AD. Association of beta3-adrenoceptor polymorphism with obesity and diabetes: current status. Trends Pharmacol Sci 1997;18: 449-455
4. Strosberg AD, Pietri-Rouxel F. Function and regulation of the beta3 adrenoceptor. Trends Pharmacol Sci 1996;17:373-381
5. Stahl SM. Essential Psychopharmacology. New York, NY: Cambridge University Press; 1996
6. Sussman N, Ginsberg D. Rethinking side effects of the selective serotonin reuptake inhibitors: sexual dysfunction and weight gain. Psychiatr Ann 1998;28:89-97
7. Stahl SM. Not so selective serotonin reuptake inhibitors. J Clin Psychiatry 1998;59:343-344
8. Sibutramine for obesity. Med Lett Drugs Ther 1998;40:32
9. Stahl SM. Psychopharmacology of Antidepressants. London, England: Dunitz Press; 1997
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Brainstorms aims to provide updates of novel concepts emerging from the neurosciences that have relevance to practitioners.
poster:jay
thread:252852
URL: http://www.dr-bob.org/babble/20030818/msgs/252852.html