Why Do I Still Have Seizures on Medication? Breakthrough Seizures
You went months without a seizure, then had one on a Tuesday afternoon for no obvious reason. Or maybe the seizures never fully stopped. Either way, the question is the same: why is this still happening when you take your medicine?
Key takeaways
A breakthrough seizure is a seizure that happens while you are on treatment, often after a period of good control.
Missed doses, short sleep, alcohol, illness and new medicines are among the most common triggers.
One breakthrough seizure with a clear trigger is different from a steady pattern. Both are worth reporting to your neurologist.
If seizures continue even when triggers are managed, specialist review and research studies may be options.
What counts as a breakthrough seizure?
"Breakthrough seizure" is an informal term for a seizure that breaks through your usual level of control. It is useful to separate two situations, because the next steps differ:
A rare seizure after a clear trigger, such as a missed dose or a night without sleep, often means the medicine is working but the trigger lowered your protection. Tell your neurologist and work on the trigger.
Seizures that keep happening even when you sleep well and take every dose may mean the current treatment is not enough for your epilepsy. Ask about a treatment review or a specialist referral.
The most common triggers, and what helps
Missed or late doses
This is the single most common cause. Pill organizers, phone alarms and linking doses to a daily habit (brushing your teeth, for example) all help. Ask your neurologist or pharmacist now, before it happens, what you should do if you miss a dose of your specific medicine, because the advice varies.
Not enough sleep
Sleep loss is one of the most powerful seizure triggers, especially in generalized epilepsies. Shift work, travel across time zones and late nights before exams are frequent culprits.
Alcohol and recreational drugs
Alcohol can interact with seizure medicines and disrupt sleep. Seizures can also occur as alcohol wears off.
Illness, fever and vomiting
Infections stress the body, and vomiting or diarrhea can stop medicine from being absorbed.
Other medicines and supplements
Some antibiotics, antidepressants, hormonal contraceptives and herbal products interact with seizure medicines. Check with your pharmacist before starting anything new.
Hormonal changes
Some women notice seizures cluster around their menstrual cycle. A diary makes this pattern visible.
Tracking triggers is much easier with a written record. Our seizure diary guide lists exactly what to write down for each event.
When to call 911
Call 911 if a seizure lasts longer than 5 minutes, another seizure follows soon after, the person has trouble breathing or waking, is injured, the seizure happens in water, or it is a first-ever seizure. These steps follow the CDC seizure first aid guidance.
When to ask for a treatment review
Contact your neurologist if your seizures become more frequent, change in how they look or feel, happen without an obvious trigger, or if side effects make it hard to take your medicine. Bring your diary and a full list of medicines and supplements.
If you have already tried two or more medicines and seizures continue, read what drug-resistant epilepsy means. That label opens the door to specialist care and newer options.
Seizures continuing even when triggers are under control? A research study may be an option.
Research for seizures that keep breaking through
Two Phase 3 studies are testing XEN1101 (azetukalner), an investigational medicine, added to current seizure medicines in people whose seizures continue.
Study snapshot: two Phase 3 epilepsy studies
What is being studied
XEN1101 (azetukalner), an investigational once-daily capsule taken with the evening meal. It is designed to act on Kv7 potassium channels, which help calm overactive electrical signals in brain cells.
How it is tested
Added to a person's current seizure medicines and compared with placebo in a randomized, double-blind design. A baseline period of up to about 9.5 weeks is followed by 12 weeks of blinded treatment.
X-ACKT (NCT05667142)
People aged 12 and older with generalized epilepsy who have primary generalized tonic-clonic seizures, have tried at least two seizure medicines, and currently take 1 to 3.
X-TOLE3 (NCT05716100)
Adults aged 18 and older with focal epilepsy diagnosed at least two years ago, who have tried at least two seizure medicines and currently take 1 to 3.
After the blinded period
People who complete the 12 weeks may be able to join a separate open-label extension study, where everyone receives XEN1101.
Where
X-ACKT has dozens of research sites across the U.S., including epilepsy centers in Boston, Philadelphia, Atlanta, Houston, Cleveland, Seattle and Los Angeles. The study team can tell you the nearest site for either study.
Both studies ask participants to keep an accurate seizure diary, because counting seizures before and during treatment is how researchers measure whether a medicine helps. For the bigger picture, see when seizures continue despite medication.
Never stop seizure medicine on your own
Stopping or changing antiseizure medicine suddenly can trigger severe seizures, including status epilepticus. Make any change only with your neurologist.
Frequently asked questions
What is a breakthrough seizure?
It is an informal term for a seizure that happens while a person is taking antiseizure medicine, often after a period of good control. It should be reported to your healthcare professional.
Can missing one dose cause a seizure?
It can for some people and some medicines. Ask your neurologist or pharmacist in advance what to do if you miss a dose of your specific medicine.
Does lack of sleep cause seizures?
Sleep deprivation is one of the most commonly reported seizure triggers, particularly in generalized epilepsies. Regular sleep is a practical way to lower risk.
When should a seizure be treated as an emergency?
The CDC advises calling 911 if a seizure lasts longer than 5 minutes, seizures happen back to back, the person has trouble breathing or waking, is injured, is in water, or it is their first seizure.