Experiences with
Gabapentin

Gabapentin is used to treat epilepsy.

It's also taken for nerve pain, which can be caused by different conditions, including diabetes and shingles. Nerve pain can also happen after an injury.

In epilepsy, it's thought that gabapentin stops seizures by reducing the abnormal electrical activity in the brain.

With nerve pain, it's thought to block pain by affecting the pain messages travelling through the brain and down the spine.

Gabapentin is available on prescription. It comes as tablets, capsules and a liquid that you swallow.

Who can take gabapentin

Gabapentin can be taken by most adults and children aged 6 and over.

Who may not be able to take gabapentin

Gabapentin is not suitable for some people.

To make sure it's safe for you, tell your doctor if you:

have ever had an allergic reaction to gabapentin or any other medicine
have ever misused or been addicted to a medicine
are trying to get pregnant or are already pregnant
are on a controlled sodium or potassium diet, or your kidneys do not work well (gabapentin liquid contains sodium and potassium, so speak to your doctor before taking it)

Dosage and strength

Each capsule of gabapentin contains 100mg, 300mg or 400mg of gabapentin. Each tablet contains 600mg or 800mg of gabapentin.

If you're taking gabapentin as a liquid, 2ml is usually the same as taking a 100mg tablet or capsule. Always check the label.

Dosage for epilepsy

The usual dose for:

adults and older children (aged 12 and over) is 900mg to 3,600mg a day, split into 3 doses
younger children (aged 6 to 12) – varies depending on their weight

Dosage for nerve pain

The usual dose to treat nerve pain in adults is 900mg to 3,600mg a day, split into 3 doses.

Changes to your dose

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 will usually stay the same.

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, you could take it first thing in the morning, early afternoon and at bedtime.

If you or your child are taking a liquid, it will come with a plastic syringe or spoon to measure your dose. If you do not have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen spoon, as it will not measure the right amount.

How long to take it for

If you have epilepsy, it's likely that once your condition is under control you'll still need to take gabapentin for many years.

If you have nerve pain, once your pain has gone you'll continue to take gabapentin for several months or longer to stop it coming back.

If you 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.

If you take too much

Taking too much gabapentin can cause unpleasant side effects.

you take more than your prescribed dose of gabapentin and:

you feel dizzy or sleepy
you have double vision
you start slurring your words
you have diarrhoea
you pass out (faint)

Get help from 111 online or call 111

If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.

Bring the gabapentin packet or leaflet inside it, any remaining medicine, and any other medicines you take.

It's important you do not suddenly stop taking gabapentin, even if you feel fine. Stopping gabapentin suddenly can cause serious problems.

If you have epilepsy, stopping gabapentin suddenly can cause seizures that will not stop.

If you're taking it for any reason and stop suddenly, you may have a severe withdrawal syndrome. This can have unpleasant symptoms, including:

anxiety
difficulty sleeping
feeling sick
pain
sweating

It's possible to prevent withdrawal seizures and other symptoms by gradually reducing the dose of gabapentin.

Do not stop taking gabapentin without talking to your doctor – you'll need to reduce your dose gradually.

Common side effects

These common side effects of gabapentin may happen in more than 1 in 100 people. They're usually mild and go away by themselves.

There are things you can do to help cope with them:

As your body gets used to gabapentin, these side effects should wear off. If they do not wear off within a week or two, your doctor may reduce your dose or increase it more slowly. If that does not work, your doctor may suggest a different medicine.

Take gabapentin with or after a meal or snack. It may also help if you do not eat rich or spicy food. Take small sips of water or other fluids to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

Take small sips of water or other fluids to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat vomiting without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice

Drink plenty of water or other fluids to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for over 24 hours while taking gabapentin, your contraception may not protect you from pregnancy. Check the pill packet for advice.

If you feel this medicine is causing mood changes, talk to your doctor. They may be able to change you to a different medicine.

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 does not get better.

Avoid driving, cycling or using tools or machinery while this is happening. If it lasts for more than a couple of days, speak to your doctor as they may need to change your treatment.

Try chewing sugar-free gum or sucking sugar-free sweets.

Speak to your doctor. They may be able to change your medicine or offer other treatments that might help with this problem.

Gabapentin can make you hungrier, so it can be hard 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.

Increasing your level of exercise will also help to keep your weight stable.

If you're having problems with your memory, speak to your doctor. They may want you to try a different medicine.

Make sure you rest and drink plenty of fluids. It's best not to 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.

If you notice this, speak to your doctor.

Keep taking the medicine, but talk to your doctor if this advice does not help and the side effects bother you or do not go away.

Very few people taking gabapentin have serious problems.

Call a doctor or call 111 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
a high temperature, swollen glands that do not go away, your eyes or skin turn yellow (this may be less obvious on brown or black skin), unusual bruises or bleeding, severe tiredness or weakness, unexpected muscle pain or weakness, with or without a rash – these may be symptoms of a serious reaction
long-lasting stomach pain, feeling sick or being sick – these may be warning signs of an inflamed pancreas
muscle pain or weakness and you're having dialysis treatment because of kidney failure
seeing things that are not there (hallucinations)

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to gabapentin.

Meds New IA (H4) - serious allergic reaction

Some people can become addicted to gabapentin. If this happens, you'll have withdrawal symptoms after you stop taking the medicine.

When you stop taking gabapentin, you'll need to reduce your dose gradually to avoid withdrawal symptoms. Do not stop taking gabapentin without talking to your doctor.

Talk to your doctor if you're concerned about becoming physically dependent on gabapentin.

Other side effects

These are not all the side effects of gabapentin. For a full list, see the leaflet inside your medicines packet.

Gabapentin and pregnancy

Gabapentin is not generally recommended in pregnancy as there is not enough information about whether it's safe for your baby.

However, from the small amount of information that is available, there's no clear evidence that it's harmful. It should only be taken if the benefits of the medicine outweigh the risks.

If you take gabapentin for epilepsy, it's important that this is well treated during pregnancy, as seizures can harm you and your baby. Keep taking gabapentin, but talk to your doctor urgently. They may recommend you change to a different medicine.

If you're trying to get pregnant or have become pregnant while taking gabapentin, it is recommended to take a high dose of folic acid (5mg a day). You can get this from your doctor or midwife.

Ideally you'll take high dose folic acid for 3 months before you start trying to get pregnant and for the first 12 weeks of pregnancy. Do not worry if you have not taken it before you get pregnant, but start taking it as soon as possible once you know that you are pregnant. It helps your baby to grow normally.

If you take gabapentin around the time of giving birth, your baby may need extra monitoring for a few days after they're born. This is because they may have withdrawal symptoms from gabapentin.

We do not know what the long term effects of taking gabapentin in pregnancy may be on childhood learning and development. For safety, you'll usually be advised to take it only if the benefits of the medicine outweigh the risks. Talk to your doctor about the benefits and risks.

Gabapentin and breastfeeding

If your doctor or health visitor says your baby is healthy, you can take gabapentin while breastfeeding. It's important to keep taking gabapentin to keep you well.

Gabapentin passes into breast milk in small amounts. It has not been known to cause any side effects in breastfed babies.

If your baby is not feeding as well as usual, seems unusually sleepy, has a stomach upset, or if you have any other concerns about your baby, talk to your doctor, pharmacist, health visitor or midwife.

Gabapentin and fertility

There's no evidence to suggest that taking gabapentin reduces fertility in either men or women. However, discuss your pregnancy plans with a doctor. They may wish to review your medicine and prescribe a higher dose of folic acid for you to take (5mg a day) before you become pregnant.

Speak to a pharmacist or your doctor before taking gabapentin if you're trying to get pregnant.

Meds New IA (H2) - Pregnancy non-urgent care card

Cautions with other medicines

Some medicines may affect how gabapentin works or increase the chance of you having side effects.

Antacids can reduce the amount of gabapentin that the body takes in so it does not work as well. To stop this happening, if you need to take an antacid, take it at least 2 hours before or after your dose of gabapentin.

Tell your doctor if you're taking any of these medicines before you start gabapentin treatment:

strong painkillers, such as morphine – these can make you very tired and dizzy when you start taking 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

Mixing gabapentin with herbal remedies or supplements

Taking herbal remedies and supplements that can make you feel dizzy or drowsy while you're taking gabapentin could make these side effects worse.

Gabapentin can intensify the highs of recreational drugs like cannabis and heroin.

So, if you use recreational drugs alongside gabapentin, there may be more chance of unpleasant side effects like panic attacks, anxiety and memory loss.

Find out more about the side effects of recreational drugs on the FRANK website.

Meds New IA (H2) - Cautions with other medicines alert