# anti-depressant balance



## trbell (Nov 1, 2000)

This is a fairly understandable summary from medscape:The Quest for Transmitter BalanceIn the treatment of some of these pain complaints, we seem to clinically need antidepressants with dual effects -- serotonergic and noradrenergic. The question to ask at this point is, "is there an ideal 'balance' between the serotonergic and noradrenergic effects of an antidepressant medication?" It appears that we need medications that affect both serotonin and norepinephrine, at least to some extent.What we mean by "balance" is not only the relative affinity for serotonin or norepinephrine, or its absolute affinity for receptor sites, --but the point at which affinity is reached. We know that venlafaxine changes its affinity across the dosage range. So we have to look not only at the specific medication agent, but the dose at which we are giving it and at what dose it is affecting both serotonin and norepinephrine.[3]It is helpful to review the relative affinities of the current drugs to serotonin and norepinephrine.[3] On the serotonin side, the spectrum runs from citalopram, the most serotonergic agent, to fluvoxamine, which is relatively serotonin selective, to sertraline, paroxetine, and fluoxetine. Fluoxetine is considered the prototype of the SSRIs, but in fact is one of the less selective ones. Venlafaxine is generally an SSRI at low doses.However, in higher doses (150 mg or above), it becomes more noradrenergic. Duloxetine, a new antidepressant medication in development, is fairly balanced and appears to hit serotonin and norepinephrine equally across the dosage range.On the norepinephrine side of the scale are many of the "tried and true" medications. Maprotiline is still the single most noradrenergic agent available. Moving up the scale, we see reboxetine and nortriptyline, and the more balanced agents, amitriptyline, imipramine, and duloxetine.In vitro studies of relative reuptake inhibition of norepinephrine and serotonin support these selectivity ratios.[39] Since these are in vitro data, we do not know entirely what happens in the human body.The Role of Substance Ptom


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