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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 11 of 11. This is the beginning of the thread.
Posted by mytwogrlsmom on May 11, 2001, at 22:59:21
I am taking 60mg of Prozac and 3.75mg of Phentermine. Someone told me this could cause a problem. Can anyone tell me more? Thank you, Renee
Posted by SalArmy4me on May 11, 2001, at 23:17:28
In reply to Seratonin Syndrome, posted by mytwogrlsmom on May 11, 2001, at 22:59:21
What the actual occurrence of serotonin syndrome is in the fluoxetine/phentermine combination I don't know, but there have been cases of it. Ask your doctor about that combo. These cases may or may not be clinically relevant to your treatment regimen:
Goldberg, Richard J. MD. Selective Serotonin Reuptake Inhibitors: Infrequent Medical Adverse Effects. Archives of Family Medicine. 7(1):78-84, January 1998.
"...It {serotonin syndrome} has been reported from the combination of fluoxetine and phentermine, an amphetamine-like appetite suppressant with sympathomimetic properties. This reaction occurred 8 days after discontinuation of fluoxetine when one 30-mg tablet of phentermine was added to the patient's treatment regimen. The patient developed severe physical and psychological activation with stomach cramps, palpitations, and tremors.Bostwick, John Michael MD. Brown, Thomas M. MD. A Toxic Reaction From Combining Fluoxetine and Phentermine. Journal of Clinical Psychopharmacology. 16(2):189-190, April 1996.
Posted by Sunnely on May 11, 2001, at 23:59:46
In reply to Seratonin Syndrome, posted by mytwogrlsmom on May 11, 2001, at 22:59:21
Hi Mytwogrlsmom,
The combination of fluoxetine (Prozac) and phentermine (Ionamin, Fastin) can lead to a potentially serious (sometimes fatal) condition called "serotonin syndrome." This condition usually results from the combination of drugs that enhance release of serotonin in the brain. There have been anecdotal reports of serotonin syndrome developing from this combination.
FYI, phentermine was one of the weight loss drugs of the once popular combination "phen-fen" ("phen" for phentermine and "fen" for fenfluramine). With the findings of heart valves problems developing from the use of fenfluramine or Pondimin and dexfenfluramine or Redux, these drugs were voluntary removed from the market. With the loss of the "fen" partner, some entrepreneurs suggested to combine "phen" with Prozac and called it "phen-pro." Eli Lilly, the manufacturer of Prozac, did not approve or endorse the use of Prozac with these combination drugs for weight loss. However, with Lilly's patent for Prozac set to expire at the end of August 2001, and generic fluoxetine then becoming available, this suggested combination may surface again. Perhaps being called "phen-fluo"?
Are you taking both drugs to lose weight or taking Prozac as an antidepressant and phentermine for weight loss? You should really discuss this drug combination with your prescriber.
++++++++++++++++++++++++++++++++++++
> I am taking 60mg of Prozac and 3.75mg of Phentermine. Someone told me this could cause a problem. Can anyone tell me more? Thank you, Renee
Posted by gritslad on May 12, 2001, at 8:28:46
In reply to Re: Seratonin Syndrome » mytwogrlsmom, posted by Sunnely on May 11, 2001, at 23:59:46
I would say get off this combo at the first sign of a manic type feeling. I was taking Prozac for my depression and a decongestant for bronchitis that contained phentermine type stuff (epinephrine?) and ended up with said Serontonin Syndrome that landed me in a psych ward for a week. Not fun. Watch yourself like a hawk.
Posted by Elizabeth on May 12, 2001, at 21:39:40
In reply to Seratonin Syndrome, posted by mytwogrlsmom on May 11, 2001, at 22:59:21
> I am taking 60mg of Prozac and 3.75mg of Phentermine. Someone told me this could cause a problem. Can anyone tell me more?
Do you mean 37.5 mg phentermine? 3.75 is, well, not much!
Anyway, no, whoever told you that is mistaken. The combination should be fine, except for possible increased psychomotor agitation.
Serotonin syndrome is unlikely. The symptoms Sal quoted do not sound like serotonin syndrome, which is a life-threatening medical emergency. They sound, instead, like the general activation syndrome that is common with SSRIs and may be exacerbated by stimulants.
Whenever you add one drug to another one, a general rule of thumb is to start at a very low dose (perhaps 18.75 mg of phentermine -- I assume the Prozac was already on board, since 60 mg is a moderately high dose).
-elizabeth
Posted by stjames on May 14, 2001, at 18:31:42
In reply to Re: Seratonin Syndrome » mytwogrlsmom, posted by Elizabeth on May 12, 2001, at 21:39:40
> Anyway, no, whoever told you that is mistaken. The combination should be fine, except for possible increased psychomotor agitation.
>
> Serotonin syndrome is unlikely. The symptoms Sal quoted do not sound like serotonin syndrome,james here....
As sal quoted the Archives of Family Medicine I would trust this source over your lay opinion.
James
Posted by Elizabeth on May 16, 2001, at 12:54:25
In reply to Re: Seratonin Syndrome, posted by stjames on May 14, 2001, at 18:31:42
> As sal quoted the Archives of Family Medicine I would trust this source over your lay opinion.
Ordinarily I would too. However, (1) it's a family medicine journal, not a psychiatric one; and, more importantly, (2) while the symptoms described are among those *associated* with the serotonin syndrome, the description was *very* generic (not including any specific symptoms of CSS) and did not sound severe enough to warrant a diagnosis of serotonin syndrome (which is generally considered to be a life-threatening emergency). Unless there were other symptoms present I would say the diagnosis was questionable at best; it sounds more like generalised activation caused or exacerbated by phentermine. The absence of changes in state of consciousness, tremor, fever, dilated pupils, manic symptoms, perceptual changes, vomiting, diarrhea, myoclonus, hyperreflexia, high/low/labile blood pressure, and other characteristic signs and symptoms of makes me skeptical of the diagnosis of serotonin syndrome (which is kind of a foggy diagnosis anyway -- a common annoyance in psychiatry < g >).
I've had CSS three times in my life (this is what happens when you go through *all* the monoaminergic antidepressants and various combinations). It landed me in the hospital each time and twice included frank delirium, as well as tremor (chattering teeth are particularly common and specific), myoclonus, rapidly fluctuating blood pressure, fever, confusion, vomiting, and dilated pupils (a sign that I believe would pretty much *have* to be present in true CSS). It goes well beyond straightforward psychomotor (or even autonomic) agitation.
I would be interested in hearing the definition or description of CSS given by Goldberg, as it may be broader than the one I was taught. It would be interesting to read the letter by Bostwick and Brown (which may or may not refer to CSS; the title doesn't specify what the "toxic reaction" was) as well.
The *peripheral* toxic reactions to "phen-fen" -- primary pulmonary hypertension and heart valve damage -- have nothing to do with the *central* serotonin syndrome that is most often associated with combinations of multiple serotonergic drugs (in most of the serious cases, a MAOI was involved). Furthermore, the "phen-fen" reactions actually believed to have no relationship to the (amphetamine-like) stimulant phentermine and were only discovered due to the widespread use of d-fenfluramine, or Redux (alone, not combined with phentermine), in the few months that it was on the market. The reaction in question is associated only with serotonin-releasing drugs (like fenfluramine, which acts like amphetamine, except on serotonin rather than on catecholamines), not with pure reuptake inhibitors (e.g., Prozac).
The odds of a serious adverse interaction between Prozac and phentermine are extremely low, but as noted, when adding a second drug, one should be especially cautious with dosing and watch for possible adverse reactions.
-elizabeth
Posted by stjames on May 16, 2001, at 13:51:06
In reply to Re: Serotonin Syndrome » stjames, posted by Elizabeth on May 16, 2001, at 12:54:25
> > As sal quoted the Archives of Family Medicine I would trust this source over your lay opinion.
>
> Ordinarily I would too. However, (1) it's a family medicine journal, not a psychiatric one; and, more importantly,James here....
To me it matters less what journal it is cited in and more the doc that writes it.
In general I think the "diet pills" are bad all round, esp. for depressives.
James
Posted by Elizabeth on May 16, 2001, at 19:31:18
In reply to Re: Serotonin Syndrome, posted by stjames on May 16, 2001, at 13:51:06
> To me it matters less what journal it is cited in and more the doc that writes it.
To me it matters more what it says than who says it or where!
> In general I think the "diet pills" are bad all round, esp. for depressives.
Phentermine is Just Another Stimulant. I don't think it's better or worse for depressives than the myriad of stimulants that are used as antidepressants (other than being weaker and probably less effective than, say, d-amphetamine).
Other diet pills are completetly different. Fenfluramine is a serotonin releaser/reuptake inhibitor and showed promise for depression and OCD before it got yanked (although I do think yanking it was the right thing, since fenfluramine-induced PPH, although rare, is irreversible and fatal). And then there's Tenuate, which looks an awful lot like Wellbutrin (emphasis on "awful" < g >).
-e
Posted by Fenka on May 17, 2001, at 0:18:51
In reply to Re: Serotonin Syndrome » stjames, posted by Elizabeth on May 16, 2001, at 12:54:25
Elizabeth, I found your post to be very informative. I have used both Ritilan and Phentermine with Prozac and had good results with either. Do you know of any specific difference between Ritilan and Phentermine, because they acted the same on me. I did not find that it caused me to lose weight as some proclaim. In fact it just made me more focused. I did have a little bit more energy, but not a lot. I just felt clearer. Thanks for your thoughts
Posted by Elizabeth on May 17, 2001, at 13:41:21
In reply to Re: Serotonin Syndrome, posted by Fenka on May 17, 2001, at 0:18:51
> Elizabeth, I found your post to be very informative.
Thank you. I'm very happy to hear I could be helpful.
> I have used both Ritilan and Phentermine with Prozac and had good results with either. Do you know of any specific difference between Ritilan and Phentermine, because they acted the same on me.
They're similar -- both are weak variations on amphetamine -- so it's no surprise that you felt similar effects from them. I don't know much about the differences between them (I'm not even sure that there has been much research into the specifics of phentermine's pharmacology). Phentermine is longer-acting and would therefore be less likely to cause mood swings during the day. (Concerta, a new sustained-release formulation of Ritalin, is supposed to be longer-acting than Ritalin SR, but it's very expensive.)
I could tell you a little about the differences between amphetamine and Ritalin (my guess being that phentermine is closer to Ritalin), but I don't know how enlightening such a discussion would be! < g >
> I did not find that it caused me to lose weight as some proclaim. In fact it just made me more focused. I did have a little bit more energy, but not a lot. I just felt clearer. Thanks for your thoughts
Sure :) Really, there is no good diet pill for losing weight and keeping it off. The weight loss from stimulants is sometimes a chronic issue for children who take them for ADHD, but it never seems to last long when people are taking them with the intention of losing weight!
-elizabeth
This is the end of the thread.
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