Posted by Don_Bristol on January 11, 2005, at 16:49:13
In reply to Re: Is Parnate potentiated by Lamisil (anti-fungal)?, posted by King Vultan on January 10, 2005, at 15:23:12
> 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.
>
> ToddTodd, I don't really understand all the subtleties of P450 but I have read the following which suggests Parnate may have some noticeable P450 activity:
"The results demonstrated that tranylcypromine is a
competitive inhibitor of CYP2C19 (Ki = 32 microM)
competitive inhibitor of CYP2D6 (Ki = 367 microM)
noncompetitive inhibitor of CYP2C9 (Ki = 56 microM).None of these inhibitory effects are considered clinically
significant at usual therapeutic doses. However, in high
dose tranylcypromine therapy, or in poor metabolizers
of CYP2C19 substrates, clinically significant interactions
might occur."And also somewhere on the Net I picked up this snippet:
"the effects of trans-(+/-)-2-phenylcyclopropylamine
(tranylcypromine), a potent CYP2A6 inhibitor, on human
liver microsomal cytochromes P450 (CYP) were studied
to elucidate its selectivity........ Potency and selectivity of tranylcypromine were
strongly dependent on the amine group,"And even this (whatever it means!!!):
"In human liver microsomes tranylcypromine induced type
II and cyclopropylbenzene type I difference spectrum.
According to the double reciprocal analysis of these
spectral responses both tranylcypromine and cyclopropyl
benzene may have at least two P450-related binding sites
in liver microsomes."It seems better agreed that, as I posted before, Lamisil is a potent inhibitor of CYP2D6.
Now what does all this mean? :-) Does it in any way help explain the fact that I had a strong "uplift" in the Parnate when I took Lamisil?
.
poster:Don_Bristol
thread:440184
URL: http://www.dr-bob.org/babble/20050108/msgs/440748.html