Posted by chemist on April 11, 2004, at 13:30:44
In reply to Re: nortriptyline, citalopram toxicity » Vera, posted by zeugma on April 11, 2004, at 12:43:44
hi vera, zeugma....zeugma is right on target in re: potential for toxicity of nortriptyline and desipramine associated with SSRIs, and i apologize for not making my logic clearer. as zeugma states, the TCAs are structurally and mechanistically similar in action and metabolism, and he/she is also correct that lexapro is a *weak* inhibitor of the metabolic isoenzymes that are involved, so the prudent advice is to follow zeugma's suggestion about checking your liver function and blood plasma levels. it always helps to establish a baseline CBC panel should any problems arise, although it is rather unlikely with lexapro given the weak inhibitory effect....all the best, chemist
> Desipramine and nortriptyline are close chemical cousins. So if the ability to process desipramine is blocked, then it's likely that nortriptyline will be subject to the same problem. Since Lexapro is probably a much weaker inhibitor of the relevant enzymes than Prozac or Paxil, the interaction is likely to be less dangerous, but it's still something to be aware of. Getting a plasma test for nortriptyline is standard practice, anyway- it is the antidepressant with the most well-defined 'therapeutic window', meaning plasma levels have to be within a certain range for optimal results to occur. I got a plasma test for nortriptyline last year, and had my dosage adjusted as a result. This made the drug more effective even though there was no concern about toxicity- it turned out my plasma levels had been too low.
>
>
poster:chemist
thread:328899
URL: http://www.dr-bob.org/babble/20040407/msgs/335226.html