Epilepsy & Women
The big issues are…
Puberty Menstruation Menopause | Contraception Pregnancy & Breast feeding Polycystic Ovaries Disease |
Puberty and Epilepsy
- Hormonal Changes:
- Rapid changes in hormone levels during puberty can impact the effectiveness of antiepileptic medication, often requiring dose adjustments or changes in medication.
- Alcohol and drug experimentation during puberty can also affect seizure incidence.
Menstruation and Epilepsy
- Catamenial Epilepsy:
- Some women experience an increase in seizure frequency between ovulation and menses.
- Theories for this increase include:
- Oestrogen and progesterone levels affecting neuronal excitability.
- Reduced blood levels of antiepileptic medication due to fluid retention.
- Premenstrual tension (PMT).
- Sleep disruption.
- Preventive Measures:
- Acetazolamide:
- A carbonic anhydrase inhibitor that blocks the Na/H exchanger.
- Taken 7-10 days before menses and continued daily until bleeding stops.
- Side effects: numbness and tingling, blurred vision, altered taste, and hypokalemia.
- Higher Dosages of Antiepileptic Medication:
- Beneficial for some patients to prevent seizure surges.
- Oral Contraceptive Pill (OCP):
- Helps regulate hormonal levels, especially useful for women with irregular cycles.
- 30-50% of women with epilepsy have irregular periods.
- Acetazolamide:
Menopause
- Hormonal and metabolic changes taking place
- Women at this time may also begin taking other medication for unrelated health problems
- There is no regular outcome for epileptic menopausal women some women report that their seizures increase or even begin and others that they decrease or disappear.
- As in puberty, menopause needs to be dealt with in each individual patient.
Contraception
- No evidence that the OCP influences epilepsy, although hormones do and the OCP influences hormones…
- The major concern is how antiepileptic medications affect the pill.
- Certain antiepileptics are known to interfere with the OCP’s metabolism:
Antiepileptics that interferes with the OCP | Antiepileptics that DO NOT interfere with the OCP |
Carbamazepine Phenytoin Phenobarbitone Primidone Topiramate Oxcarbazepine Clonazepam Clobazam | Sodium valproate Gabapentin Lamotrigine Tiagabine Levetiracetam Vigabatrin Ethosuximide |
→ additional contraceptive methods are strongly recommended.
Pregnancy
Epilepsy and Babies: Key Points
Healthy Delivery:
- 93% of women with epilepsy will deliver a normal healthy baby.
Teratogenic Risk of Antiepileptic Drugs:
- Antiepileptic drugs are teratogenic but pose less risk than uncontrolled seizures.
- Strong recommendation for women to reduce antiepileptic medications to one and at the lowest possible dose, especially during the first trimester.
- Using three medications increases the risk of abnormalities to 10%.
Specific Drug Risks:
- Phenytoin, Carbamazepine, and Valproic Acid:
- May cause abnormalities including cleft palate, cardiac defects, digital hypoplasia, and nail dysplasia.
- Valproic Acid and Carbamazepine:
- Associated with a 1-2% incidence (double the normal rate) of neural tube defects.
Incidence of Foetal Abnormalities:
- Incidence in epileptic women: 5-6%.
- Incidence in non-epileptic women: 2-3%.
Pregnancy and Mothers with Epilepsy: Key Points
- Conception Challenges:
- Women with epilepsy may have difficulty conceiving due to irregular ovulation.
- Seizure Frequency Changes During Pregnancy:
- 50% of women experience no change in seizure frequency.
- 30% of women experience an increase in seizures.
- 20% of women experience a decrease in seizures.
- Reasons for Seizure Changes:
- Endocrine effects of the CNS.
- Changes in the pharmacokinetics of antiepileptic drugs (AEDs) during pregnancy.
- Changes in medication compliance.
- Medication Management:
- Ideally, use only one AED at the lowest possible dosage for the patient.
- AED Levels and Dose Adjustment:
- Pregnancy can significantly alter AED pharmacokinetics due to changes in body weight, drug absorption, protein binding, metabolism, and excretion.
- It is recommended to monitor drug concentrations during pregnancy.
- For patients with good seizure control, serum concentration should be assessed each trimester. More frequent assessments may be required for those with complicated epilepsy.
- Surveillance for Birth Defects:
- An ultrasound examination at 11–13 weeks should be offered to women with epilepsy, especially those taking AEDs.
- Supplements:
- Folate: 5 mg daily (10 times the normal dose).
- Vitamin K: Recommended for women on phenytoin, phenobarbital, and primidone in the last two weeks of pregnancy and for the baby at birth.
- Breastfeeding:
- AEDs are found in breast milk at varying levels depending on the specific drug.
- Despite this, breastfeeding is recommended for epileptic mothers due to the significant benefits to the baby.
Polycystic Ovaries
- Polycystic ovaries affects 6% of Australian women
- 20-40% of epileptic women have polycystic ovaries
- It is important as a clinician to be aware of this