Download CONTRACEPTIVE CHOICES FOR WOMEN WITH EPILEPSY

CONTRACEPTIVE CHOICES FOR WOMEN WITH EPILEPSY
Guidelines
A statement from the Special Interest Group in Epilepsy in the
South West Peninsula of England
These Guidelines, produced by the Peninsula Special Interest Group, are believed correct at
time of print. They are compiled to inform Doctors, when seeing women of childbearing age
who have epilepsy and need some form of contraception. Information has been gathered from
a number of sources including pharmaceutical companies. It is intended that information will
continue to be updated and the guidelines reviewed as and when necessary. It is not the
intention of the Group to dictate the prescribing practices of their colleagues but to offer useful
information to aid appropriate treatment choices for their patients. The Group cannot be held
responsible for the clinical practices of their colleagues, when offering this advice.
Some women who have seizures can experience an increase in seizure activity at the time of
ovulation (when oestrogen levels rise) and at the start of menstruation (when progesterone
levels fall).
An important link between hormone levels and epilepsy can determine the choice of hormonal
contraception that is prescribed. There is a risk that hormonal contraceptive pills will be less
effective when combined with enzyme inducing anti-epileptic drugs (AEDs). Some AEDs
enhance the metabolism of contraceptive hormones, including phenytoin, carbamazepine,
phenobarbitone, primidone, topiramate and lamotrigine. Glaxo-Smith-Kline has recently issued
a statement informing prescribers of the interaction between hormonal contraception and
lamotrigine. GSK state the possibility of decreased contraceptive efficacy in some patients
cannot be excluded. GSK also report that adjustments in the dosage of lamotrigine maybe
needed in a few patients who are using the progesterone OC compounds, since lamotrigine
levels can be decreased. Oxcarbazepine may also be a weak enzyme inducer and may have
this effect. Other anti-epileptic medications may also have the potential to increase the
metabolism of hormones and thereby reduce the contraceptive effect. Therefore it is important,
when prescribing hormonal contraception that this is taken into account.
The prescription of the combined oral contraceptive pill does fall into the World Health
Organisation category 3, which advises caution particularly in two situations.

The first situation is in conditions where the theoretical or proven risks usually outweigh
the advantages.

The second situation is in relation to respect for the patient’s autonomy in determining
her health. In other words, when a person accepts the risks and also rejects (or should
not use) alternatives, then a method can be used with caution and additional care.
With this in mind and where there is risk of interaction, a woman who is taking anti-epileptic
medication should be prescribed higher doses of hormonal contraception. It is recommended
that this should be at least 50ug of ethinyloestradiol or of mestranol. In order to achieve this, a
regimen of 50ug or more or a combination of two different combined oral contraceptives may be
required. However, this use of combined oral contraceptives is unlicensed and should be
discussed and documented with the patient, doctor or other prescribing person.
When breakthrough bleeding occurs, the dosage of hormones should be increased. This can
be undertaken by so-called tricycling, namely by taking three packets of the combined oral
contraceptive pill consecutively, without a break. At the end of that time a four-day break may
be introduced, although there is little evidence that this is more effective. Indeed a steady
hormonal balance may reduce the frequency of seizures.
When enzyme-inducing drugs, including some anti-epileptic drugs, are discontinued, high
dosage combined oral contraceptives and barrier contraception should be continued for at least
a further four weeks since the enzyme induction continues for four weeks after withdrawal of
the medication.
Some special situations apply
Evra Patch

This is a transdermal patch and trials have not been undertaken in women taking
enzyme-inducing medication.
Progesterone only Pill


This may be used when other options are not available and the dosage can be
increased to two pills daily and, when the body weight is over 70 kilograms, three pills
daily.
However, this is an unlicensed use of the progesterone-only pill and should be
discussed and documented.
Implanon

This progestogen-only single rod, introduced under the skin, protects for three years but
is contra-indicated with enzyme inducing drugs including some anti-epileptic medication.
Depo Provera

This is a very effective method as it inhibits ovulation. Furthermore, liver enzyme
inducers do not alter it so there is no need to alter the 12-week injection interval.

Women already established on 8/10-week regimen may wish to continue but should be
made aware that evidence to support this practice is lacking.

This drug may cause weight gain and skin problems and is not advised for women
receiving treatment for depression. Caution should also be used in the presence of a
low body mass index (BMI) due to the increased risk of early osteoporosis.
Emergency Contraception (Levonelle)

This compound contains progestogen-only in a dosage of 75 ug in each pill. It should be
used as early as possible and followed by a pregnancy test three weeks later.

In women taking enzyme-inducing drugs, the dosage should be increased by 50%,
which requires that three tablets be taken within 72 hours of unprotected sexual
intercourse.

This can be done as a single dose or two tablets of levonelle together followed by one
tablet 12 hours later.
IUCD



This intra-uterine contraceptive device does not have an effect on the menstrual cycle.
However a seizure may be induced during insertion due to the parasympathomimetic
stress.
It may be used as emergency contraception up to five days after unprotected sexual
intercourse and then left in place for 5/8 years depending on the type of coil used.
When fitted in a woman aged over 40 years it may be left in place until the menopause
has been completed.
IUS (MIRENA)
 This coil has an added progestogen that is not absorbed systemically and it is very
helpful for women with heavy painful periods. It may inhibit ovulation and can be
beneficial around the time of the menopause since it can be used as the progestogen
component of HRT (hormone replacement therapy). Current licensing states that the
Mirena needs to be changed after five years. It cannot be used as emergency
contraception.
Recommended further reading:
Frye C.A, An overview of oral contraceptives – mechanism of action and clinical use. Neurology
2006;66 (Suppl 3):S29-S36
Zupanc M.L, Antiepileptic drugs and hormonal contraceptives in adolescent women with
epilepsy. Neurology 2006;66 (Suppl 3):S37-S45
PEIG/2005-08-04