INDICES> interaction between lamotrigine and quetiapine?(2)

[Kirsten Myhr <myhr@online.no>]

INDICES> interaction between lamotrigine and quetiapine?(2)
---------------------------------------------------

A colleague, clinical pharmacologist, who works with me found a
reference
that might be of interest.
I copy the abstract (from Pubmed) below.

Regards

Kirsten

Kirsten Myhr
Head, Eastern Region Drug Information Centre
Ulleval University Hospital
0407 Oslo, Norway
Tel.: +47 23 01 64 11(o)   Fax: +47 23 01 64 10
+47 22 56 05 85 (h)   mobile: +47 416 38 747
myhr@online.no
www.relis.no

Fundam Clin Pharmacol 2000 Jul-Aug;14(4):301-1
Enzyme induction and inhibition by new antiepileptic drugs: a review
of
human studies.
Benedetti MS.
UCB Pharma, Nanterre, France. margherita.strolin@ucb-group.com
The aim of this paper is to review a number of new antiepileptic
agents
(i.e. felbamate, gabapentin, lamotrigine, levetiracetam,
oxcarbazepine,
tiagabine, topiramate, vigabatrin and zonisamide) for their inducing
and/or
inhibitory properties in humans, mainly considering the interactions
where
they are involved as the cause rather than the object of such
interactions.
Two aspects have been particularly taken into account: the changes or
absence of changes in plasma/serum concentrations of concomitant drugs
and
the direct or indirect evidence of induction, inhibition or lack of
effect
on the six major human hepatic CYP isozymes (CYP1A2, CYP2C9, CYP2C19,
CYP2D6, CYP2E1 and CYP3A4), as well as on other CYP isozymes or enzyme
systems. Felbamate clearly affects the pharmacokinetics of a number of
drugs, generally increasing but also decreasing their concentrations.
It
induces enzymes such as CYP3A4 and inhibits enzymes such as CYP2C19
and
those of the beta-oxidation pathway. Topiramate is not devoid of
potential
interaction properties: it decreases the plasma concentrations of
ethinylestradiol, induces CYP3A4 and inhibits CYP2C19. For
oxcarbazepine,
no inhibitory, only inductive effects have been observed thus far.
Felbamate. topiramate and oxcarbazepine may induce the metabolism of
steroidal oral contraceptives. In this respect, tiagabine has been
studied
at a rather low dose. Pharmacodynamic or pharmacokinetic interaction
seems
to exist between lamotrigine and carbamazepine. Lamotrigine appears to
be a
weak inducer of UGTs, whereas induction of CYP3A4 seems improbable as
the
compound does not change the concentrations of oral contraceptives or
the
urinary excretion of 6beta-hydroxycortisol. Zonisamide has very
peculiar
pharmacokinetics and an extensive metabolism. Additional information
on its
enzyme inducing or inhibiting properties would be necessary, as data
so far
collected on its effect on the pharmacokinetics of other drugs are
conflicting. Gabapentin, vigabatrin and in particular levetiracetam
appear
to be devoid of significant enzyme inducing or inhibiting properties.




--
Send mail for the `INDICES' conference to `indices@usa.healthnet.org'.
Mail administrative requests to `majordomo@usa.healthnet.org'.
For additional assistance, send mail to:  `owner-indices@usa.healthnet.org'.