The effects of the oral
contraceptives may possibly be disturbed (either inter-menstrual
bleeding or amenorrhoea) if
griseofulvin is taken concurrently. There are reports of 4
women taking oral
contraceptives who became pregnant while taking
griseofulvin.
Similarly, progestogen-only emergency hormonal
contraceptives are considered to be
less effective in those taking
griseofulvin. The situation with progestogen-only oral
contraceptives is not clear, but it has been suggested that they are not the
contraceptive of choice in those taking
griseofulvin because of increased menstrual
irregularities.
As
griseofulvin is potentially teratogenic it has been recommended that a barrier method is used during and for 1 month after taking
griseofulvin. For general advice on the use of
enzyme inducers, such as griseofulvin, and
contraceptives, see
contraceptives.