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Gabapentin Bristol Labs 100 mg capsules – patient leaflet, side effects, dosage

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Key facts
Status:
Prescription only (POM) Controlled drug (Schedule 3)
Medicine strength:
100 mg
Contains active substance:
ATC code:

Patient leaflet - Gabapentin Bristol Labs 100 mg capsules

1. What Gabapentin Capsules are and what they are used for

Gabapentin belongs to a group of medicines used to treat epilepsy and peripheral neuropathic pain (long lasting pain caused by damage to the nerves).

The active substance is gabapentin.

Muscle weakness, tenderness or pain and particularly, if at the same time, you feel unwell or have a high temperature it may be caused by an abnormal muscle breakdown which can be life-threatening and lead to kidney problems. You may also experience discoloration of your urine, and a change in blood test results (notably blood creatine phosphokinase increased). If you experience any of these signs or symptoms, please contact your doctor immediately.

Other medicines and Gabapentin Capsules

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. In particular, tell your doctor (or pharmacist) if you are taking or have been recently taking any medicines for convulsions, sleeping disorders, depression, anxiety, or any other neurological or psychiatric problems.

Medicines containing opioids such as morphine

If you are taking any medicines containing opioids (such as morphine), please tell your doctor or pharmacist as opioids may increase the effect of Gabapentin. In addition, combination of Gabapentin with opioids may cause sleepiness, sedation, decrease in breathing, or death.

Antacids for indigestion

If Gabapentin and antacids containing aluminium and magnesium are taken at the same time, absorption of Gabapentin from the stomach may be reduced. It is therefore recommended that Gabapentin is taken at the earliest two hours after taking an antacid.

Gabapentin can cause dependence, tolerance and addiction, and you may get withdrawal symptoms if you stop taking it or reduce the dose suddenly. Your prescriber should have explained how long you will be taking it for and, when it is appropriate to stop, how to do this safely. When your treatment is stopped, it is usually done gradually over a period which is specific to you and may occur over a period of weeks to months. If this medicine is being used for the treatment of epilepsy you must continue to take it as prescribed by your doctor.

Gabapentin:

  • is not expected to interact with other anti-epileptic drugs or the oral contraceptive pill.
  • may interfere with some laboratory tests, if you require a urine test tell your doctor or hospital what you are taking.

Gabapentin Capsules with food, drink and alcohol

The capsules can be taken with or without food.

Gabapentin is used to treat:

  • Various forms of epilepsy (seizures that are initially limited

    to certain parts of the brain, whether the seizure spreads to other parts of the brain or not).

  • The doctor treating you or your child 6 years of age and

    older will prescribe Gabapentin to help treat epilepsy when the current treatment is not fully controlling the condition. You or your child 6 years of age and older should take Gabapentin in addition to the current treatment unless told otherwise. Gabapentin can also be used on its own to treat adults and children over 12 years of age’.

  • Peripheral neuropathic pain (long lasting pain caused by

    damage to the nerves). A variety of different diseases can cause peripheral neuropathic pain (primarily occurring in the legs and/or arms), such as diabetes or shingles. Pain sensations may be described as hot, burning, throbbing, shooting, stabbing, sharp, cramping, aching, tingling, numbness, pins and needles etc.

    Pregnancy, breast-feeding and fertility

    • If you are pregnant or think you may be pregnant, you must

      tell your doctor straight away and discuss possible risks the medicine you are taking might pose to your unborn baby • If you are planning to become pregnant you should discuss

      your treatment with your doctor as early as possible before you become pregnant

    • You should not stop your treatment without discussing this

      with your doctor.

    • If you are pregnant or breast-feeding, think you may be

      pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Pregnancy

Gabapentin should not be taken during pregnancy, unless you are told otherwise by your doctor.

Effective contraception must be used by women of child-bearing potential.

2. What you need to know before you take

Gabapentin Capsules

There have been very few studies specifically looking at the use of gabapentin in pregnant women.

Do not take Gabapentin Capsules:

  • If you are allergic (hypersensitive) to gabapentin or any of

    the other ingredients of this medicine (listed in section 6)

    More research is needed to better understand the safety of use of gabapentin during pregnancy and whether it is associated with an increased risk of harm to the unborn child.

Warnings and Precautions

Talk to your doctor, pharmacist or nurse before taking Gabapentin capsules:

  • if you suffer from kidney problems your doctor may

    prescribe a different dosing schedule

  • if you are on haemodialysis (to remove waste products

    because of kidney failure), tell your doctor if you develop muscle pain and/or weakness

  • if you develop signs such as persistent stomach pain,

    feeling sick and being sick contact your doctor immediately as these may be symptoms of acute pancreatitis (an inflamed pancreas)

  • if you have nervous system disorders, respiratory

    disorders, or you are more than 65 years old, your doctor may prescribe you a different dosing regimen • if you are or have ever been addicted to opioids, alcohol,

    prescription medicines, or illegal drugs, or if you have ever had a history of struggling to control your alcohol or drug intake.

  • if you have previously suffered from withdrawal symptoms

    such as agitation, anxiety, shaking or sweating, when you have stopped taking alcohol or drugs.

  • if you feel you need to take more of Gabapentin to get the

    same level of symptom control, this may mean you are developing tolerance to the effects of this medicine or are becoming addicted to it. Speak to your prescriber who will discuss your treatment and may change your dose or switch you to an alternative medication.

  • If you have myasthenia gravis (a disease causing muscle

    weakness) because this medicine may make your symptoms worse.

A small number of people being treated with anti-epileptics such as gabapentin have had thoughts of harming or killing themselves. If at any time you have these thoughts, immediately contact your doctor.

Some medicines used to treat epilepsy have reported an increased risk of harm to the developing baby, particularly when more than one seizure medication is taken at the same time. This means that where possible, your doctor should consider using one epilepsy medicine to control your epilepsy.

In a study reviewing data from women in Nordic countries who took gabapentin in the first 3 months of pregnancy, there was no increased risk of birth defects or problems with the development of brain function (neurodevelopment disorders). However, babies of women who took gabapentin during pregnancy had an increased risk of low birth weight and preterm birth. If used during pregnancy, gabapentin may lead to withdrawal symptoms in newborn infants. This risk might be increased when gabapentin is taken together with opioid analgesics (drugs for treatment of severe pain).

Do not suddenly discontinue taking this medicine as this may lead to a breakthrough seizure, which could have serious consequences for you and your baby.

Breast feeding

Gabapentin is passed on through human milk. Because the effect on the baby is unknown, it is not recommended to breast-feed while using Gabapentin.

Fertility

There is no effect on fertility in animal studies.

Driving and using machines

Gabapentin Capsules may produce dizziness, drowsiness and tiredness. You should not drive,operate complex machinery or take part in other potentially hazardous activities until you know whether this medication affects your ability to perform these activities.

Dependence

Taking this medicine regularly, particularly for a long time, can lead to physical dependence and addiction. Your prescriber should have explained how long you will be taking it for and, when it is appropriate to stop, how to do this safely. When your treatment is stopped, it is usually done gradually over a period which is specific to you and may occur over a period of weeks to months.

Physical dependence and addiction can cause withdrawal symptoms when you stop taking this medicine. Withdrawal symptoms can include: trouble sleeping, headache, nausea, feeling anxious, diarrhoea, flu-like symptoms, convulsions, nervousness, depression, thoughts of harming or killing yourself, pain, sweating, and dizziness.

Your prescriber will discuss with you how to gradually reduce your dose before stopping the medicine. It is important that you do not stop taking the medicine suddenly as you will be more likely to experience withdrawal symptoms. Your prescriber will ensure that your plan for stopping treatment is tailored to you and can be adapted according to your needs and experience of any withdrawal symptoms.

Gabapentin capsules contain Lactose

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicinal product.

3. How to take Gabapentin Capsules

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Do not take more medicine than prescribed.

Your prescriber should have discussed with you how long the course of capsules will last. They will arrange a plan for stopping treatment. This will outline how to gradually reduce the dose and stop taking the medicine. Your prescriber will ensure that your plan for stopping treatment is tailored to you and can be adapted according to your needs and experience of any withdrawal symptoms.

Method and route of administration

For oral use only. Always swallow the capsules whole with plenty of water. Continue taking Gabapentin until your doctor tells you to stop.

Gabapentin should only be used by those they are prescribed for. Do not give your medicine to anyone else. Taking higher doses or more frequent doses of Gabapentin, may increase the risk of addiction. Overuse and misuse can lead to overdose and/or death.

Epilepsy, the recommended dose is:

Adults and adolescents:

Take the number of capsules as instructed. Your doctor will usually build up your dose gradually.

The starting dose will generally be between 300 mg and 900

Size: 180 x 560 mm

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180 mm

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mg each day. Thereafter, the dose may be increased as instructed by your doctor, up to a maximum of 3600 mg each day and your doctor will tell you to take this in 3 separate doses, i.e. once in the morning, once in the afternoon and once in the evening.

Children aged 6 years and above:

The dose to be given to your child will be decided by your doctor as it is calculated against your child’s weight. The treatment is started with a low initial dose which is gradually increased over a period of approximately 3 days. The usual dose to control epilepsy is 25-35 mg per kg of body weight per day. It is usually given in 3 separate doses, by taking the capsule (s) each day, usually once in the morning, once in the afternoon and once in the evening.

Gabapentin is not recommended for use in children below 6 years of age.

Peripheral Neuropathic Pain, the usual dose is: Adults: Take the number of capsules or tablets as instructed by your doctor. Your doctor will usually build up your dose gradually. The starting dose will generally be between 300 mg and 900 mg each day. Thereafter, the dose may be increased as instructed by your doctor, up to a maximum of 3600 mg each day and your doctor will tell you to take this in 3 separate doses, i.e. once in the morning, once in the afternoon and once in the evening.

Your doctor may prescribe a different dosing schedule and/or dose if you have problems with your kidneys or are undergoing haemodialysis.

  • High blood pressure, flushing or dilation of blood vessels • Difficulty breathing, bronchitis, sore throat, cough, dry nose
  • Vomiting (being sick), nausea (feeling sick), problems with teeth, inflamed gums, diarrhoea, stomach pain, indigestion, constipation, dry mouth or throat, flatulence
  • Facial swelling, bruises, rash, itch, acne
  • Joint pain, muscle pain, back pain, twitching • Difficulties with erection (impotence)
  • Swelling in the legs and arms, difficulty with walking, weakness, pain, feeling unwell, flu-like symptoms • Decrease in white blood cells, increase in weight • Accidental injury, fracture, abrasion

Additionally in clinical studies in children, aggressive behaviour and jerky movements were reported commonly.

Uncommon: may affect up to 1 in 100 people:

  • Mental impairment
  • Racing heartbeat
  • Swelling that may involve the face, trunk and limbs • Abnormal blood test results suggesting problems with the liver
  • Fall
  • Allergic reactions such as hives
  • Increase in blood glucose levels (most often observed in patients with diabetes)
  • Agitation (a state of chronic restlessness and unintentional and purposeless motions)
  • Decreased movement
  • Difficulty swallowing

If you are an elderly patient (over 65 years of age), you should take the normal dose of Gabapentin unless you have problems with your kidneys. Your doctor may prescribe a different dosing schedule and/or dose if you have problems with your kidneys.

Rare: may affect up to 1 in 1,000 people

  • Loss of consciousness
  • Decrease in blood glucose levels (most often observed in patients with diabetes)
  • Trouble breathing, shallow breaths (respiratory depression)

If you have the impression that the effect of Gabapentin is too strong or too weak, talk to your doctor or pharmacist as soon as possible.

If you take more Gabapentin Capsules than you should

Higher than recommended doses may result in an increase in side effects including loss of consciousness, dizziness, double vision, slurred speech, drowsiness and diarrhoea. If you or someone else accidentally takes too many capsules, or if you think a child has swallowed any, contact your doctor or go to your nearest hospital casualty department immediately. Take along any capsules that you have not taken, together with the container and the label so that the hospital can easily tell what medicine you have taken. As Gabapentin capsules may make you drowsy, it is recommended that you ask someone else to drive you to the doctor or hospital, or that you call an ambulance.

If you forget to take Gabapentin Capsules

If you forget to take a dose, take it as soon as you remember unless it is time for your next dose. Do not take a double dose to make up for a forgotten dose.

If you stop taking Gabapentin Capsules

Do not suddenly stop taking Gabapentin or reduce your dose. If you want to stop taking Gabapentin or reduce your dose, discuss this with your doctor first. They will tell you how to do this, usually by reducing the dose gradually so that any unpleasant withdrawal effects are kept to a minimum. This may occur over a period of weeks to months. Your prescriber will ensure that your plan for stopping treatment is tailored to you and can be adapted according to your needs and experience of any withdrawal symptoms. After stopping a short or long-term treatment with Gabapentin or after reducing your dose, you need to know that you may experience certain side effects, so-called withdrawal effects. These effects can include seizures, anxiety, difficulty sleeping, feeling sick (nausea), pain, sweating, shaking, headache, depression, feeling abnormal, dizziness, feeling generally unwell, diarrhoea, flu-like symptoms, convulsions, nervousness and thoughts of harming or killing yourself.

If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.

Not known: frequency cannot be estimated from the available data

  • Decreased platelets (blood clotting cells)
  • Hallucinations
  • Problems with abnormal movements such as writhing, jerking movements and stiffness
  • Ringing in the ears
  • Yellowing of the skin and eyes (jaundice), inflammation of the liver
  • Acute kidney failure, incontinence
  • Increased breast tissue, breast enlargement
  • Adverse events following the abrupt discontinuation of gabapentin (anxiety, difficulty sleeping, feeling sick, pain, sweating), chest pain,
  • Breakdown of muscle fibers (rhabdomyolysis) • Change in blood test results (creatine phosphokinase increased)
  • Problems with sexual functioning including inability to achieve a sexual climax, delayed ejaculation • Low blood sodium level
  • Suicidal thoughts
  • dependence and addiction (see section “How do I know if I am tolerant or addicted?”).
  • Worsening of myasthenia gravis (a disease causing muscle weakness)

Drug Withdrawal

When you stop taking Gabapentin, you may experience drug withdrawal symptoms, which include: trouble sleeping, headache, nausea, feeling anxious, diarrhoea, flu-like symptoms, convulsions, nervousness, depression, thoughts of harming or killing yourself, pain, sweating, and dizziness.

How do I know if I am tolerant or addicted?

If you notice any of the following signs whilst taking Gabapentin, it could be a sign that you have become addicted.

  • You may feel the need to keep taking the medication for longer than your doctor recommended
  • You feel you need to use more than the recommended dose
  • You are using the medicine for reasons other than prescribed
  • When you stop taking the medicine you feel unwell, and you feel better once taking the medicine again

If you notice any of these signs, it is important you talk to your prescriber.

4. Possible Side Effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Stop using Gabapentin and seek medical attention immediately if you notice any of the following symptoms: • reddish non-elevated, target-like or circular patches on the

trunk, often with central blisters, skin peeling, ulcers of mouth, throat, nose, genitals and eyes. These serious skin rashes can be preceded by fever and flu-like symptoms (Stevens-Johnson syndrome, toxic epidermal necrolysis). • Widespread rash, high body temperature and enlarged lymph

nodes (DRESS syndrome or drug hypersensitivity syndrome).

  • Anaphylaxis (serious, potentially life threatening allergic

    reaction including difficulty breathing, swelling of the lips, throat, and tongue, and hypotension requiring emergency treatment)

Contact your doctor immediately if you experience any of the following symptoms after taking this medicine as they can be serious:

  • severe skin reactions that require immediate attention,

    swelling of the lips and face, skin rash and redness and/or hair loss (these may be symptoms of a serious allergic reaction)

  • breathing problems, which if severe you may need

    emergency and intensive care to continue breathing normally

  • persistent stomach pain, feeling sick and being sick as these

    may be symptoms of acute pancreatitis (an inflamed pancreas)

  • Gabapentin Capsules may cause a serious or life

    threatening allergic reaction that may affect your skin or other parts of your body such as your liver or blood cells. You may or may not have rash when you get this type of reaction. It may cause you to be hospitalized or to stop Gabapentin. Call your doctor right away if you have any of the following symptoms: skin rash and redness and/or hair loss, hives, fever, swollen glands that do not go away, swelling of your lip, face and tongue, unusual bruising or bleeding, severe fatigue or weakness, unexpected muscle pain, frequent infections, yellowing of your skin or of the whites of the eyes

The symptoms may be the first signs of a serious reaction. A doctor should examine you to decide if you should continue taking Gabapentin capsules.

If you are on haemodialysis, tell your doctor if you develop muscle pain and/or weakness.

Other side effects include:

Very common: may affect more than 1 in 10 people

  • Viral infection
  • Feeling drowsy, dizziness, lack of coordination • Feeling tired, fever

Common: may affect up to 1 in 10 people

  • Pneumonia, respiratory infections, urinary tract infection,

    inflammation of the ear or other infections

  • Low white blood cell counts
  • Anorexia, increased appetite
  • Anger towards others, confusion, mood changes,

    depression, anxiety, nervousness, difficulty with thinking • Convulsions, jerky movements, difficulty with speaking,

    loss of memory, tremor, difficulty sleeping, headache, sensitive skin, decreased sensation (numbness), difficulty with coordination, unusual eye movement, increased, decreased or absent reflexes

  • Blurred vision, double vision, vertigo

    Reporting of side effects

    If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

5. How to store Gabapentin Capsules

  • Keep this medicine out of the sight and reach of children. • Do not use this medicine after the expiry date (EXP) which is stated on the carton.

    The expiry date refers to the last day of that month.

    0 • Do not store above 25 C. Store in the original package. • Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information

What Gabapentin Capsules contain

  • The active substance is Gabapentin. Each capsule contains

    100mg, 300mg or 400mg Gabapentin.

    The other ingredients are:

  • Capsule fill: Lactose Monohydrate, Maize Starch, Talc. Capsule shell: Gelatin, Titanium dioxide (E171) The 300mg Capsules contain Yellow Iron Oxide (E172); the 400mg Capsules contain:

    Yellow Iron Oxide (E172), Red Iron Oxide (E172) • Printing ink: Shellac, Strong ammonia solution, Black iron oxide(E172).

What Gabapentin Capsules look like and contents of the pack

100mg: Hard gelatin capsule with white cap/white body and printed with “BL 100”.

300mg: Hard gelatin capsule with yellow cap/yellow body and printed with “BL 300’’.

400mg: Hard gelatin capsule with orange cap/orange body and printed with “BL 400’’.

All strengths are available in blister pack of 10 x 10 capsules. 400mg strength is also available in blister pack of 5 x 20 capsules.

Marketing Authorisation Holder and Manufacturer:

Name and address: Bristol Laboratories Ltd,

Unit 3, Canalside, Northbridge Road, Berkhamsted, Hertfordshire, HP4 1EG, United Kingdom

Telephone:0044 (0)1442 200922

Email: info@bristol-labs.co.uk

Manufacturer

Bristol Laboratories Ltd.

Laporte Way, Luton, LU4 8WL, United Kingdom.

Gabapentin Bristol Labs 100 mg, 300 mg, 400 mg Capsules; PL 17907/0371, PL 17907/0372, PL 17907/0373

This leaflet was last revised in March 2026

To request a copy of this leaflet in Braille, large print or audio format then please contact the licence holder at the address (telephone or email) above.

V27 24-03-26 D0

Size: 180 x 560 mm

Back

180 mm

About this document

Source: MHRA - Medicines and Healthcare products Regulatory Agency (products.mhra.gov.uk) · Marketing authorisation: PL 17907/0371

Last revision stated in the text: March 2026 · MHRA data as of 13 October 2026

What the sections and the side effect frequencies mean: How to read a patient leaflet

Found a mistake? Tell us on the contact page.

The information on this site does not replace the advice of a doctor or pharmacist.

Facts about Gabapentin Bristol Labs 100 mg capsules

What these facts mean

Prescription needed?? Yes, prescription-only medicine (POM)
Controlled drug?
Yes, Schedule 3 of the Misuse of Drugs Regulations?
  • Controlled drugs are medicines that UK law controls more strictly because they can be misused or cause dependence. The Misuse of Drugs Regulations 2001 divide them into 5 schedules: schedule 1 has the strictest rules and schedule 5 the least strict.
  • Schedule 3 includes, for example, tramadol, gabapentin, pregabalin and buprenorphine.
  • A prescription is valid for 28 days and usually covers up to 30 days of treatment. In England it cannot be issued as a repeat dispensing prescription.
  • Travelling abroad: carry it in your hand luggage, take your prescription or a letter from your doctor to show it is yours, and check the rules of the country you are going to with its embassy before you travel (GOV.UK).
Active substance? Gabapentin
Strength? 100 mg
Pharmaceutical form? Oral capsule
Hard gelatin capsule with white cap/white body and printed with ''BL 100''
How is it taken? Oral
Excipients? Lactose monohydrate, Maize starch, Talc, Titanium dioxide (E171), Gelatin, Shellac, Strong ammonia solution, Black iron oxide (E172)
Pack sizes 100 capsule
Is it available?? Listed as available (NHS Dictionary of Medicines and Devices – not a record of current supplies)
Shelf life? 2 years
Storage Do not store above 25°C. Store in the original package.
Drug group (ATC)?
  1. N Nervous system drugs
    1. N03 Antiepileptics
      1. N03A Antiepileptics
        1. N03AX Other antiepileptics
          1. N03AX12 gabapentin
Marketing authorisation? PL 17907/0371 (first authorised 14 October 2024)
Marketing authorisation holder? Bristol Laboratories Limited
Codes? GTIN 5060013943096 · BNF 04080100

Sources: the MHRA product information (products.mhra.gov.uk) and the NHS Dictionary of Medicines and Devices (dm+d), release 11.1.0 of 9 November 2026, NHS Business Services Authority. Contains public sector information licensed under the Open Government Licence v3.0.