Epilepsy and Contraception

Contraception and Epilepsy

Some anti-epileptic drugs (AEDs) reduce the effectiveness of hormonal contraception, making it essential to choose options that provide reliable protection.

Medications That Decrease Contraceptive Efficacy

Enzyme-inducing AEDs speed up the metabolism of hormonal contraceptives, making them less effective. These include:

• Carbamazepine
• Phenytoin
• Phenobarbital
• Primidone
• Topiramate (at high doses)
• Oxcarbazepine
• Lamotrigine

This can impact combined oral contraceptives, progestogen-only pills, and implants.

Contraceptive Options

Managing contraception and heavy periods can be challenging when taking antiepileptic medications, as some can make certain contraceptives less effective. This limits the available options, but there are still great choices that provide reliable contraception and help manage heavy bleeding.

Best Options:

Depo-Provera (Medroxyprogesterone Injection) "the jab"

A progestogen-only injection given every 12 weeks. It’s not affected by antiepileptic medications and offers highly effective contraception with the added benefit of often stopping periods altogether. Some people experience irregular bleeding at first, but many find it hugely convenient—no pills to remember, no daily hassle.

Mirena (Levonorgestrel IUD)

A small, hormone-releasing intrauterine device that provides up to 8 years of contraception and significantly reduces or even stops periods for most people. Unlike other hormonal methods, it works mostly in the uterus, so side effects are minimal. It’s also one of the most effective and low-maintenance options available.

Both choices offer freedom from daily contraception worries while helping to manage heavy periods, making them excellent options for those on epilepsy medications.

More information

Depot Provera (Medroxyprogesterone Injection)

Effectiveness: Not affected by enzyme-inducing AEDs.  But recommendation of shorter inter injection frequency eg ~10 weeks.

Risks:

• Irregular bleeding: Can cause prolonged or unpredictable spotting, especially in the first few months.
• Weight gain: Some users experience increased appetite and weight changes.
• Bone density concerns: Long-term use may reduce bone mineral density, though this risk is likely lower in Māori and Pasifika populations. If needed, estrogen supplementation can help.
• Delayed return to fertility: It can take up to 12-18 months for periods to return after stopping.
• Mood changes: Some people report low mood or depressive symptoms, which may be a consideration in those with epilepsy, as mood disorders can be more common.
• Pain at the injection site: Mild discomfort or local irritation may occur.

Benefits:

• Highly effective (94-99%) with no daily adherence needed.
• May stop periods completely, which can be beneficial for those with heavy or painful cycles.
• Can be used in people with epilepsy without interaction concerns.
• Reduced risk of endometrial cancer with long-term use.

Mirena (Levonorgestrel IUD)

Effectiveness: Not significantly affected by enzyme-inducing AEDs.

Risks:

• Irregular bleeding: In the first 3-6 months, bleeding may be unpredictable, though this usually settles.
• Insertion discomfort: Some people experience pain during insertion, but this is short-lived.
• Expulsion: Rare but possible (2-10% risk in the first year).
• Hormonal side effects: Some may experience mood changes, bloating, or acne, though systemic hormone absorption is low.

Benefits:

• Highly effective (>99%) for contraception.
• Long-lasting (up to 5-8 years), with no daily effort required.
• Can significantly lighten or stop periods (great for those with heavy bleeding).
• Minimal systemic hormone absorption, making it a good option for those sensitive to hormones.
• Rapid return to fertility after removal.