Special issues in the management of epilepsy
Females with epilepsy
For women of child bearing potential with epilepsy, the main concerns are adequate contraception and when pregnancy
is planned, safety during pregnancy and labour. GPs can be actively involved in helping educate women with epilepsy about
the pros and cons of treatment with anticonvulsants and provide advice on contraception and pre-conception care.
Anticonvulsants and contraception
Several anticonvulsants, in particular carbamazepine and phenytoin, increase the metabolism of oestrogen and progestogen
and therefore reduce the effectiveness of the combined oral contraceptive (COC). Topiramate and lamotrigine may also
reduce the effectiveness of the COC to a lesser extent. Sodium valproate does not affect oestrogen metabolism.
It is recommended that women taking enzyme inducing anticonvulsants who require contraception, be prescribed a COC
containing at least 50 μg of oestrogen. Mid cycle bleeding can be an indication that the oestrogen dose is inadequate.
In this situation the options are to advise that:16
- The oestrogen dose can be increased by taking two 30 μg pills per day (and in some cases up to two 50 μg pills per
- The COC can be taken continuously for three months with a four day break between cycles
- A barrier form of contraception be used concurrently
- An alternative method of contraception may be more appropriate.
The use of enzyme inducing anticonvulsant medications (e.g. carbamazepine, phenytoin) may also reduce the effectiveness
of the progesterone only pill (POP). The POP therefore is not recommended for women who are taking anticonvulsants.
Barrier methods, depot medroxyprogesterone acetate (DMPA, Depo-Provera), standard intrauterine contraceptive devices
(IUCD) and the levonorgestrel intrauterine system (Mirena) are effective and may be suitable choices.20 However,
because both DMPA and some anticonvulsants are associated with weight gain and lower bone mineral density with long term
use, DMPA may not be a first line choice in some women.20,21 If DMPA is used, it is recommended that the interval
between injections is shortened to ten weeks.11
If emergency contraception is required for women taking enzyme inducing anticonvulsants, it is usually recommended
that twice the normal dose of the progesterone-only emergency contraceptive pill should be taken.16,21 An
IUCD fitted within five days of unprotected intercourse could be offered as an alternative.20
As many anticonvulsants are associated with an increased risk of neural tube defects, it is recommended that all women
of child bearing potential who are taking anticonvulsants take folic acid 5 mg/day.11,22 Once pregnant, folic
acid (5 mg daily) should be continued for the first trimester.
Women with epilepsy who are planning a pregnancy should be referred for specialist advice. The combined input of both
a neurologist and an obstetrician is usually required.
Anticonvulsants and pregnancy
Carbamazepine, or lamotrigine in doses under 200 mg/day, when used as monotherapy, are the anticonvulsant drugs of
choice in pregnancy.23,24
The use of the majority of anticonvulsant medications increases the risk of teratogenicity. The risk of major congenital
malformation in the general population is approximately 2–3% compared to 4–7% in women taking anticonvulsant medications.22 The
risk is higher for the older anticonvulsant medications (especially sodium valproate) when combination therapy is required
or when anticonvulsants are taken at higher doses.22,23
The type of congenital malformation varies with the type of anticonvulsant medication, e.g., sodium valproate is associated
with neural tube, craniofacial, skeletal, cardiovascular and urogenital defects. Exposure of the foetus to sodium valproate
may also be associated with development delay and cause cognitive impairment.25
In some women, anticonvulsant treatment can be safely withdrawn before pregnancy, although this should be confirmed
by a specialist. If tonic clonic seizures are likely to occur during pregnancy then an anticonvulsant should be continued
because these seizures are likely to be harmful to both mother and foetus.
The challenge is to strike a balance between the risk of uncontrolled seizures and the risk of teratogenicity. Ideally,
use a single anticonvulsant at the lowest possible dose to maintain seizure control.
Anticonvulsants and breast feeding – guidelines advise that most women taking anticonvulsants can breast feed safely.16
Limited alcohol is usually acceptable
Alcohol is a CNS depressant and lowers seizure threshold. Although a very small amount of alcohol can be enough to
trigger a seizure in some people with epilepsy, the majority can safely consume a limited amount of alcohol. Excess consumption
of alcohol, binge drinking or acute withdrawal from alcohol can induce seizures, even in a patient with no history of
A small to modest intake (one to two drinks per occasion, totalling no more than three to six drinks per week) is suggested
as a safe upper level of alcohol intake. This amount has been shown not to alter serum concentrations of anticonvulsants
and not to increase the frequency of seizures.26
Best practice tip: It is safer to advise patients that some alcohol is allowed
while on anticonvulsant medication, rather than risk a situation where patients do not take their medication when they
Epilepsy and driving
Any person who has a seizure, irrespective of cause, should receive advice about driving.
Patients who have had a single seizure, without a diagnosis of epilepsy, are subject to the same driving restrictions
as patients with a formal diagnosis of epilepsy.
A patient with epilepsy controlled by treatment may still be able to hold a licence to drive a private motor vehicle.
However, a diagnosis of epilepsy for a driver of a commercial vehicle will result in the permanent loss of this class
of licence, in most circumstances.
A medical practitioner is required to notify the Director of Land Transport Safety if they are aware that a patient
with uncontrolled seizures continues to drive. This should be discussed with the patient first who should be offered
the opportunity to seek a second opinion if required.
Full information can be found in “Medical aspects of fitness to drive – A Guide for Medical Practitioners” which
is available online at:
This guide has recently been updated and there have been some minor changes to the section on epilepsy.