The clinical effectiveness of the delayedrelease
combination of doxylamine and
pyridoxine has been documented over a
span of 50 years by several randomized,
controlled trials as well as in open postmarketing
studies. In addition, several
placebo-controlled clinical trials have
been published, the results of which
have confirmed the effectiveness of this
combined agent (Table).
Compelling evidence supporting the
effectiveness of this delayed-release combination
was provided by populationbased
studies showing that the
withdrawal of the pyridoxine-doxylamine
combination from the US in 1983 was
temporally related to a 2- to 3-fold increase
in the rates of hospitalization of
women for NVP.3 These data suggest
that the doxylamine-pyridoxine combination
is not only capable of eradicating
mild and moderate forms of NVP, but
also of preventing severe cases. Data
presented by Neutel reiterate these findings:
during the 1990s the increased
use of the pyridoxine-doxylamine combination
by Canadian women has been
associated with a reduction in the hospitalization
rates for severe NVP.
In conclusion, with the availability of
a safe and effective FDA-approved
drug for NVP, there is no reason for
women to be exposed to a drug of unproven
maternal and fetal safety, which
has not been labeled for NVP.