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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 9 of 9. This is the beginning of the thread.
Posted by magicpill on June 3, 2007, at 13:18:29
Li SX, Perry KW, Wong DT
Influence of fluoxetine on the ability of bupropion to modulate extracellular dopamine and norepinephrine concentrations in three mesocorticolimbic areas of rats. [Journal Article]
Neuropharmacology 2002 Feb; 42(2) :181-90.
The finding that serotonin (5-HT) can modulate dopamine (DA) and norepinephrine (NE) release in the brain has led us to hypothesize that fluoxetine, a selective 5-HT reuptake inhibitor, may influence the ability of bupropion, a preferential DA and NE dual reuptake inhibitor, to modulate extracellular DA and NE concentrations in some brain areas. The present study was designed to evaluate this hypothesis by assessing the effects of fluoxetine on bupropion-induced changes in extracellular monoamine concentrations by means of in vivo microdialysis. Three mesocorticolimbic areas including hypothalamus (Ht), prefrontal cortex (Pfc) and nucleus accumbens (Acb) were selected based on their relevance to depression and antidepressant actions. In the Ht of untreated rats, bupropion dose-dependently (s.c.) increased extracellular DA and NE concentrations either in single injection study or in sequential injection study. Thus, 10 mg/kg of bupropion had no effect on the DA and NE concentrations, while 30 mg/kg of bupropion induced transient but significant increases (about 240% of the baselines), and 100 mg/kg of bupropion induced marked and persistent increases (over 600% of the baselines) in the DA and NE concentrations. In the rats pre-treated with fluoxetine (10 mg/kg, s.c., 90 min interval), the threshold dose of bupropion (10 mg/kg) significantly increased the DA and NE concentrations to more than 350% of the baselines, and 30 mg/kg of bupropion markedly increased the DA and NE concentrations to more than 570% of the baselines in the Ht. The fluoxetine pre-treatment also potentiated the DA increases induced by 10 mg/kg of bupropion in the Pfc (260% for bupropion alone vs 357% for the combination) and in the Acb (224% vs 645%). The bupropion-induced NE increases were potentiated by fluoxetine mainly in the Ht. Bupropion did not significantly affect the extracellular 5-HT concentrations in all the 3 brain areas tested. In summary, the present study demonstrated that bupropion can increase extracellular DA and NE concentrations in several mesocorticolimbic areas, which may have an impact on bupropion's antidepressant actions. Furthermore, fluoxetine can potentiate the bupropion-induced DA and NE increases, which may produce more effective and rapid antidepressant actions.
Posted by Phillipa on June 3, 2007, at 13:25:08
In reply to Fluoxetine potentiates bupropion, posted by magicpill on June 3, 2007, at 13:18:29
Sorry to be so dense but could you explain it in easier words? Thank Phillipa
Posted by Racer on June 3, 2007, at 14:16:32
In reply to Re: Fluoxetine potentiates bupropion » magicpill, posted by Phillipa on June 3, 2007, at 13:25:08
What that abstract is saying is that Prozac makes Wellbutrin more effective.
In medium words ;-), Prozac potentiates the action of Wellbutrin. When they gave rats Wellbutrin, there were dose dependent increases in dopamine and norepinephrine, but they were pretty mild increases. When they gave the rats Prozac first, though, the increases went up a huge amount. There were three doses given the rats -- 10mg per kg of body weight, 30mg/kg, and 100mg/kg -- and they produced increases of roughly 0%, 240%, and 600% above baseline respectively. The 10mg/kg and 30mg/kg doses, after the rats were pretreated with Prozac, produced increases of 350% and 570% in the hypothalamus. The Prozac pretreatment also affected the release of dopamine in the prefrontal cortex, although not norepinephrine in that area.
What this means, is that Wellbutrin may be more effective at lower doses if given with a low dose of Prozac. Wellbutrin is often not a terribly robust antidepressant on its own, and this suggests that adding a low dose of Prozac might boost its powers.
How's that? Easier words, and medium words. A bonus! And if you have any other questions, ask away...
Posted by Sandra62 on June 3, 2007, at 14:52:17
In reply to Easier words » Phillipa, posted by Racer on June 3, 2007, at 14:16:32
Racer you are a genius, thanks for clarifying!
Posted by Phillipa on June 3, 2007, at 20:20:06
In reply to Easier words » Phillipa, posted by Racer on June 3, 2007, at 14:16:32
Racer I interpreted it completely different. To me when I tried it prozac was very stimulating and so was wellbutrin didn't take them together. So in other words a stimulating ad like prozac means less wellbutrin as you can only take 450 with out fears of seizures. Man I'd be manic on those two meds together. Thanks so much. Too much technical stuff here so much. Love Phillipa
Posted by Phillipa on June 3, 2007, at 20:21:39
In reply to Re: Easier words, posted by Sandra62 on June 3, 2007, at 14:52:17
Sandra did you understand the first post or are you like me? love Phillipa
Posted by Iansf on June 3, 2007, at 23:59:38
In reply to Easier words » Phillipa, posted by Racer on June 3, 2007, at 14:16:32
> What this means, is that Wellbutrin may be more effective at lower doses if given with a low dose of Prozac. Wellbutrin is often not a terribly robust antidepressant on its own, and this suggests that adding a low dose of Prozac might boost its powers.
>Is there any way to interpolate the data in terms of human dosage to determine how much Prozac would be needed to potentiate the Wellbutrin, and how low a dose of Wellbutrin might then be effective? Might, say, 5mg of Prozac be sufficient to make 150mg of Wellbutrin effective? Or will we have to wait for followup human studies for any indication in this regard?
Posted by Sandra62 on June 4, 2007, at 12:55:15
In reply to Re: Easier words » Racer, posted by Phillipa on June 3, 2007, at 20:20:06
Posted by Racer on June 4, 2007, at 18:31:15
In reply to Re: Easier words » Racer, posted by Iansf on June 3, 2007, at 23:59:38
> > What this means, is that Wellbutrin may be more effective at lower doses if given with a low dose of Prozac. Wellbutrin is often not a terribly robust antidepressant on its own, and this suggests that adding a low dose of Prozac might boost its powers.
> >
>
> Is there any way to interpolate the data in terms of human dosage to determine how much Prozac would be needed to potentiate the Wellbutrin, and how low a dose of Wellbutrin might then be effective? Might, say, 5mg of Prozac be sufficient to make 150mg of Wellbutrin effective? Or will we have to wait for followup human studies for any indication in this regard?Well, you could use the numbers involved in this study, and extrapolate based on body weight, but I doubt it would do a lot of good. For one thing, rats and humans may not respond similarly.
The biggest thing, though, is that this study only looked at how much of the neurotransmitter was available in the brain. That doesn't necessarily correlate to effectiveness as an antidepressant.
So, it's still hit or miss...
I will say, though, that 5mg of Prozac has boosted my 450mg of Wellbutrin XL... Not that that means anything much...
This is the end of the thread.
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