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I received information regarding Tasmar and have forwarded it below. Dominic Question: If Tasmar blocks the action of COM-T, does Tasmar inadvertently contribute to accelerated dopamine-producing neuronal cell death? Do some studies indicate that Tasmar hastens cell death? Answer: The only studies I'm aware of that have been conducted to-date with Tasmar, looking at the potential effect on dopamine-producing neurons, are all in-vitro cell culture experiments. Basically, dopamine-producing cells are grown in cell culture media and then Tasmar is exposed to the cells to see how they react. These studies have shown hastened cell death when Tasmar is added. Does that mean that Tasmar contributes to cell death in-vivo? Absolutely not! These cell culture environments bear very little correlation to what may happen in the brain. Here's why. First, in the brain, dopamine-producing neurons are surrounded by astrocytes, oligodendrocytes, and microglia cells. These specialized glial cells provide structural support but also serve to protect the dopamine-producing neurons from trauma, external insults, and infection. The activity of the glial cells can be thought of as the immune system for the CNS. The outcome of an experiment that looks at the effect of a compound on dopamine-producing neurons, without the inclusion of glial cells, cannot be considered predictive in-vivo. Second, remember that dopamine is metabolized via two metabolic pathways. Inhibiting COM-T, in all probability, just results in an increase in MAO-B activity. And lastly, it is still not clear that Tasmar acts centrally by crossing the blood-brain barrier. And even if it does, the amount of Tasmar entering the CNS is several orders of magnitude less than the concentrations used in these in-vitro experiments. Bottom-line: There is no evidence that Tasmar has any negative effect on cell survival in-vivo. However, given the side effect issues that have surfaced over the past several months, I would try to keep the dosage levels at the 100mg TID level, and be very cautious about going higher.