topiramate at a glance
Medicine class
Antiseizure medicine
Main licensed uses
Epilepsy treatment and adult migraine prevention
Taking it
Can be taken with or without food; tablets are swallowed whole
Pregnancy safeguards
A Pregnancy Prevention Programme applies to patients who could become pregnant
What is topiramate used for?
Selected UK products are licensed for:
Treatment on its own of partial-onset seizures, with or without secondary generalisation, and primary generalised tonic-clonic seizures in adults, adolescents and children over 6 years.
Additional treatment for partial-onset or primary generalised tonic-clonic seizures, and seizures associated with Lennox–Gastaut syndrome, in adults, adolescents and children aged 2 years and over.
Prevention of migraine in adults after other options have been considered; it is not an acute migraine treatment.
How does topiramate work?
Its precise clinical mechanism is not fully established. It affects sodium channels, GABA signalling, glutamate signalling and carbonic anhydrase, helping to calm excessive neuronal activity involved in seizures and migraine susceptibility.
topiramate preparations and strengths
Capsule
Route: Oral
Strengths: 15 mg, 25 mg, 50 mg
Oral solution
Route: Oral
Strengths: 20 mg
Oral suspension
How to take topiramate
Follow the directions for the prescribed product and do not stop it suddenly without clinical advice.
Tablets should be swallowed whole with water and may be taken with or without food.
Shake oral suspension thoroughly and measure it with the supplied oral syringe.
Measure oral solution using its supplied syringe; wash the syringe with water afterwards.
Sprinkle capsules may be swallowed whole or opened onto a small spoonful of soft food. Swallow immediately without chewing and do not store the mixture.
Maintain adequate fluid intake, particularly during exercise or hot weather.
topiramate side effects
Common or expected effects
- Tingling or altered sensation
- Sleepiness, dizziness or tiredness
- Difficulty concentrating, remembering or finding words
- Reduced appetite or weight loss
- Nausea or diarrhoea
- Taste changes
- Blurred or double vision
- Low mood or irritability
Get urgent medical advice
- Sudden visual disturbance or eye pain
- Painful, blistering or peeling rash
- Kidney-stone symptoms or urinary infection symptoms
- Deep breathing, marked tiredness, nausea or an irregular heartbeat
- Reduced sweating with overheating, particularly in children
- New suicidal thoughts, severe mood change or unusual behaviour
- Severe allergy with facial or throat swelling or breathing difficulty
topiramate in pregnancy
Exposure in pregnancy is associated with congenital malformations, impaired fetal growth and possible neurodevelopmental harm. It is contraindicated for migraine prevention during pregnancy and for epilepsy unless no suitable alternative controls seizures. Patients who could become pregnant must meet Pregnancy Prevention Programme requirements. Anyone who becomes pregnant while taking it should contact their clinician promptly; treatment for epilepsy must not be stopped suddenly without specialist advice.
topiramate while breastfeeding
Topiramate passes into breast milk. Breastfeeding may be possible after an individual assessment of benefits and risks; monitor the baby for poor feeding, unusual sleepiness or irritability, diarrhoea and inadequate weight gain.
topiramate interactions
Ask a pharmacist or prescriber to check all medicines, contraception and supplements. Important examples include:
Systemic hormonal contraceptives
Topiramate may reduce contraceptive effectiveness; contraception must be reviewed as part of the Pregnancy Prevention Programme.
Phenytoin or carbamazepine
They can lower topiramate exposure, while topiramate can occasionally increase phenytoin levels.
Valproate
The combination can cause hyperammonaemia, encephalopathy or hypothermia.
Common questions about topiramate
Answers are fully visible for fast scanning and source review.
Does topiramate treat a migraine that has already started?
No. Its licensed migraine role is prevention; it is not intended to relieve an acute attack.
Can topiramate be stopped suddenly?
Usually not. Sudden withdrawal can cause seizures or make them more frequent, so stopping should be clinically supervised.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.