Posted by King Vultan on January 10, 2005, at 15:23:12
In reply to Is Parnate potentiated by Lamisil (anti-fungal)?, posted by don_bristol on January 10, 2005, at 14:38:37
> Does anyone know of the interaction between the anti-fungal medication Lamisil (terbinafine) and Parnate?
>
> I have been taking 40 mg Parnate for a few months. Recently I had to take 250 mg of oral Lamisil for 6 weeks.
>
> Maybe it was just a co-incidence but soon after I started taking the Lamisil I felt the Parnate was much "stronger" than usual. I was more wakeful and had trouble wanting to go to sleep as I was not feeling sleepy at nights. I would estimate that the effect was equivalent to something like an extra 10 to 15 mg Parnate.
>
> (Also my regular sleeping medication 10mg Zolpidem i.e. Ambien seemed to be much more potent when I was on Lamisil. This time it seemed to double in strength.)
>
> I am not sure it was merely co-incidence. But there is little info on Lamisil interactions with MAOIs. The most explicit I have found is this from http://www.healthdigest.org/TERBINAFINE-(Oral)-(Tablet)_6749_PRO.php
>
> "Make sure your doctor knows if you are also using cimetidine .... , blood pressure medicine .... , an MAO inhibitor (Eldepryl, Marplan, Nardil, Parnate), or medicine for depression (amitriptyline, clomipramine, ....".
>
> Can anyone who understands the chemistry say if the P450 enyzme system explains why Lamisil *seemed* to block the breakdown of Parnate?
>
> It is said that Lamisil is a potent inhibitor of CYP2D6. I don't really understand this topic but I have read that Parnate is a potent inhibitor of CYP2A6 as well as having something to do with several other enzymes in the P450 system.
>
> Does anyone have any further info on this topic?
>
> Thank you for any information.
>
> Don.
>
AFAIK, Parnate is not metabolized by the CYP-450 enzyme system in general or the 2D6 enzyme in particular. Rather, it is metabolized by the MAO enzyme system, of which it is a potent inhibitor, and from which its antidepressant properties are derived.Todd
poster:King Vultan
thread:440184
URL: http://www.dr-bob.org/babble/20050108/msgs/440202.html