Gabapentin is used to treat epilepsy.
Occasionally, gabapentin is used to treat migraine headaches.
Gabapentin is available on prescription. It comes as capsules, tablets, and a liquid that you drink.
- It's usual to take gabapentin 3 times a day. You can take it with or without food.
- Most people who take gabapentin don't get any side effects. The most common ones are feeling sleepy, tired and dizzy. Side effects are usually mild and go away by themselves.
- It takes at least a few weeks for gabapentin to work.
- You don't need to have epilepsy for gabapentin to help with pain or migraine.
- The most common brand name is Neurontin.
Gabapentin can be taken by adults and children aged 6 years and over.
Gabapentin isn't suitable for some people.
To make sure gabapentin is safe for you, tell your doctor if you:
- have ever had an allergic reaction to gabapentin or other medicines in the past
- have ever misused or been addicted to a medicine
- are trying to get pregnant, pregnant or breastfeeding
- are on a controlled sodium or potassium diet, or your kidneys don't work well (gabapentin liquid contains sodium and potassium, so speak to your doctor before taking it)
Gabapentin is a prescription medicine. It's important to take it as advised by your doctor.
How much to take
The usual dose of gabapentin to:
- treat epilepsy in adults and older children (aged 12 years and over) is between 900mg and 3,600mg a day split into 3 doses
- treat nerve pain in adults is between 900mg and 3,600mg a day split into 3 doses
- prevent migraine in adults varies, but can be up to 2,400mg a day split into 3 doses
The dose of gabapentin used to treat epilepsy in younger children (aged 6 to 12 years) varies depending on their weight.
If you're taking gabapentin as a liquid, 1ml is usually the same as taking a 50mg tablet or capsule. Always check the label.
How to take it
Swallow gabapentin capsules and tablets whole with a drink of water or juice. Do not chew them.
You can take gabapentin with or without food, but it's best to do the same each day.
Try to space your doses evenly through the day. For example, first thing in the morning, early afternoon and at bedtime.
If you or your child are taking a liquid, it'll come with a plastic syringe or spoon to measure your dose.
Do not use a kitchen spoon, as it will not give the right amount.
If you don't have a spoon, ask your pharmacist for one.
Will my dose go up or down?
To prevent side effects, your doctor will prescribe a low dose to start with and then increase it over a few days.
Once you find a dose that suits you, it'll usually stay the same.
How long will I take it for?
If you have epilepsy, it's likely that once your illness is under control you'll still need to take gabapentin for many years.
If you have nerve pain, it's likely that once the pain has gone you'll continue to take gabapentin for several months to stop it coming back.
What if I forget to take it?
If you forget a dose, take it as soon as you remember.
If it's within 2 hours of the next dose, it's better to leave out the missed dose and take your next dose as normal.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you have epilepsy, it's important to take this medicine regularly. Missing doses may trigger a seizure.
If you forget doses often, it may help to set an alarm to remind you.
You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
What if I take too much?
Taking too much gabapentin by accident can cause unpleasant side effects.
Like all medicines, gabapentin can cause side effects, although not everyone gets them.
Common side effects
These common side effects may happen in more than 1 in 100 people.
They're usually mild and go away by themselves.
Keep taking the medicine, but talk to your doctor if these side effects bother you or don't go away:
- feeling sleepy, tired or dizzy
- feeling sick (nausea)
- being sick (vomiting) and diarrhoea
- getting more infections than usual
- mood changes
- swollen arms and legs
- blurred vision
- dry mouth
- difficulties for men getting an erection
- weight gain - gabapentin can make you feel hungry
- memory problems
Serious side effects
Very few people taking gabapentin have serious problems.
Call a doctor straight away if you have a serious side effect, including:
- thoughts of harming or killing yourself - a small number of people taking gabapentin have had suicidal thoughts, which can happen after only a week of treatment
- yellowing of your skin or whites of your eyes - these may be warning signs of jaundice
- unusual bruises or bleeding - these may be warning signs of a blood disorder
- long-lasting stomach pain, feeling sick or vomiting - these may be warning signs of an inflamed pancreas
- muscle pain or weakness and you're having dialysis treatment because of kidney failure
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to gabapentin.
These aren't all the side effects of gabapentin.
For a full list, see the leaflet inside your medicines packet.
What to do about:
- feeling sleepy, tired or dizzy - as your body gets used to gabapentin, these side effects should wear off. If they don't wear off within a week or two, your doctor may reduce your dose or increase it more slowly. If that doesn't work, you may need to switch to a different medicine.
- feeling sick (nausea) - take gabapentin with or after a meal or snack. It may also help if you don't eat rich or spicy food.
- being sick (vomiting) and diarrhoea - drink plenty of water or other fluids to avoid dehydration. Take small sips if you feel sick. Signs of dehydration include peeing less than usual or having dark strong-smelling pee. Do not take any other medicines to treat diarrhoea or vomiting without speaking to a pharmacist or doctor.
- mood changes - if you feel this medicine is causing mood changes, talk to your doctor. You may be able to change to an alternative medicine.
- swollen arms and legs - try sitting with your feet raised and try not to stand for a long time. Gently exercising your arms might help. Talk to your doctor if this doesn't get better.
- blurred vision - avoid driving or using tools or machines while this is happening. If it lasts for more than a day or two, speak to your doctor as they may need to change your treatment.
- a dry mouth - chew sugar-free gum or suck sugar-free sweets.
- difficulties for men getting an erection - speak to your doctor, as they may be able to change your medicine or offer other treatments that might help with this problem.
- weight gain - gabapentin can make you hungrier, so it can be quite a challenge to stop yourself putting on weight. Try to eat a healthy, balanced diet without increasing your portion sizes. Do not snack on foods that contain a lot of calories, such as crisps, cakes, biscuits and sweets. If you feel hungry between meals, eat fruit and vegetables and low-calorie foods. Regular exercise will also help to keep your weight stable.
- memory problems - if you're having problems with your memory, speak to your doctor. They may want to try a different medicine.
- headaches - make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Headaches should usually go away after the first week of taking gabapentin. Talk to your doctor if they last longer than a week or are severe.
Gabapentin is not generally recommended in pregnancy.
There's no firm evidence that it's harmful to an unborn baby, but for safety pregnant women are usually advised to take it only if the benefits of the medicine outweigh the potential harm.
If you take gabapentin for epilepsy and become pregnant, do not stop the medicine without talking to your doctor first.
It's very important that epilepsy is treated during pregnancy as seizures can harm you and your unborn baby.
If you're trying to get pregnant or have become pregnant, you're routinely recommended to take at least 400mcg of a vitamin called folic acid everyday. It helps the unborn baby grow normally.
Pregnant women who take gabapentin are recommended to take a higher dose of folic acid.
Your doctor might prescribe a high dose of 5mg a day for you to take during the first 12 weeks of pregnancy.
If you take gabapentin around the time of giving birth, your baby may need extra monitoring for a few days after they're born because they may have gabapentin withdrawal symptoms.
For more information about how gabapentin can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.
Gabapentin and breastfeeding
Usually, you can breastfeed while taking gabapentin.
Check with your doctor first though if your baby is premature or has kidney problems.
There aren't usually any problems mixing gabapentin with other medicines.
Some indigestion remedies, called antacids, reduce the amount of gabapentin that the body takes in so it doesn't work as well.
To stop this happening, take an antacid at least 2 hours before or after your dose of gabapentin.
For safety, tell your doctor if you're taking these medicines before you start gabapentin treatment:
- strong painkillers, such as morphine - these can increase the tiredness and dizziness you can feel when you start gabapentin
- antidepressants, such as amitriptyline or fluoxetine
- antipsychotic medicines for mental health problems like schizophrenia or bipolar disorder
- a medicine to prevent malaria called mefloquine
- a weight loss medicine called Orlistat - it may stop gabapentin working as well
Mixing gabapentin with herbal remedies or supplements
There are no known problems with taking herbal remedies and supplements with gabapentin.