Posted by SLS on March 23, 2009, at 7:04:51
In reply to Re: Nardil to Parnate » Cseagraves, posted by Ron Hill on March 23, 2009, at 0:15:44
> > Do you have to wait two weeks when switching from Nardil to Parnate?
> -------------
>
> Courtney,
>
> The Parnate Prescribing Information document says to wait "at least one week". See the bottom of page 2:
>
> http://us.gsk.com/products/assets/us_parnate.pdf
>
> -- Ron
I can't provide any proof of this (I forgot where I read it), but I think it is much more important to wait 14 days going from Nardil to Parnate than it is for the reverse. Nardil has a half-life that is 5-6 times longer than that of Parnate, and it is influenced by its own presence. It inhibits its own metabolism through the very mechanism that gives it its therapeutic effect - MAO inhibition. I think its half-life is exponential at 60mg per day and above. MAO inhibition just seems to persist longer with Nardil. I believe that the rate of elimination of Nardil and the recovery of MAO activity are just too variable to take a chance on waiting less than 2 weeks between its discontinuation and the initiation of Parnate treatment. Parnate can produce a hypertensive event in the absence of prior MAO inhibition. This risk must certainly be higher when residual MAOI is present.There are more than just a handful of anecdotes describing cerebrovascular accident (CVA) as a consequence of switching between MAOIs too quickly.
- Scott
poster:SLS
thread:885679
URL: http://www.dr-bob.org/babble/20090322/msgs/886651.html