Posted by Larry Hoover on August 1, 2008, at 7:41:07
In reply to elimination of nortrip. + metabolites, how long?, posted by iforgotmypassword on July 29, 2008, at 10:22:05
> looking up it's half life seems to be confusing. wikipedia says 16 AND 90 hours. is the latter referring to a metabolite? (?)
No, it's a typo. The reference Clinical Pharmacology lists the half-life as 16-90 hours. However, I suspect even that requires some contextualizing.
Nortriptyline depends entirely on the enzyme 2D6 for metabolizing. The measured rates of this enzyme vary immensely across the population. Last time I looked, the range of activities varied by 2 orders of magnitude (more than 100-fold). Moreover, some people have zero activity. For those poor sods, the only excretion route is renal, and that is slow. Toxic concentrations can quickly build in susceptible individuals.
A recent metabolic study found the mean half-life to be 39 hours. You'd have to know your own 2D6 function, as well as your intake of 2D6 inhibitors (there are quite a few), to really answer your question, however.
I couldn't find any information about whether the sole metabolite has any biological activity, nor what its half-life is.
Lar
poster:Larry Hoover
thread:842803
URL: http://www.dr-bob.org/babble/20080727/msgs/843444.html