Posted by Elizabeth on July 3, 2001, at 16:11:42
In reply to Does carbamazepine work on these chemicals?, posted by SalArmy4me on July 1, 2001, at 23:45:55
> Does it work on serotonin, norepinephrine, or dopamine?
Tegretol has a broad range of effects, direct and indirect. It blocks voltage-gated sodium channels to reduce high-frequency action potentials. It may also block calcium channels.
It also has effects on neurotransmission (although some of these may be due to its primary effects on ion channels). The neurotransmitters that have been found to be affected by CBZ include adenosine, aspartate, acetylcholine, GABA, glutamate, and substance P, as well as the monoamines. It's a direct antagonist at adenosine receptors. A single dose increases firing in the locus coeruleus (a region which is dense with NE neurons) and inhibits the release of glutamate. Chronic/long-term effects include increased numbers of adenosine receptors; increased levels of substance P and sensitivity of substance P receptors; increased free tryptophan in plasma; and decreased GABA turnover. It may interact with peripheral-type benzodiazepine receptors. It also affects second-messenger systems, decreasing the activity of adenylate and guanylate cyclases. There's probably some other stuff I'm missing; it's a very complicated drug whose mechanisms of action (particularly in affective disorders) are not well understood.
In relation to the monoamines, it seems to activate 5-HT1a receptors and increase prefrontal dopamine concentrations. It causes increased serotonin release. It enhances monoaminergic transmission. It may decrease the turnover of dopamine and/or norepinephrine. It is not a dopamine antagonist.
It does work in some cases of depression that don't respond to conventional antidepressants, although it's not clear (as you can see) just *how* it works in depression (or, for that matter, in mania).
-elizabeth
poster:Elizabeth
thread:68693
URL: http://www.dr-bob.org/babble/20010701/msgs/68846.html