The concurrent use of
carbamazepine and
efavirenz leads to a modest reduction in the
plasma levels of both drugs. The use of
nevirapine and
carbamazepine may also result
in decreased levels of both drugs.
The manufacturers of
efavirenz note that an alternative to
carbamazepine should
be considered (especially with doses of greater than 400 mg daily). If both drugs
are given it would seem prudent to their monitor
plasma levels (where possible),
and
efficacy.