Patient leaflet - Gabapentin 300 mg capsules
1. What Gabapentin is and what it is used for
This medicine has been prescribed for you for epilepsy or neuropathic pain.
It contains gabapentin, which belongs to a class of medicines called Gabapentinoids. Gabapentin is used as an anticonvulsant for the treatment of various types of epilepsy. It is used to reduce the risk of an epileptic fit or to stop one that is in progress.
Anticonvulsant drugs stop the excessive electrical activity in your brain which is causing epileptic fits. You should take gabapentin in addition to your current treatment unless your doctor tells you otherwise.
It can also be used on its own to treat adults and children over 12 years of age.
Gabapentin belongs to a group of medicines used to treat chronic (long lasting) pain caused by damage to the nerves. This pain is known as peripheral neuropathic pain. Peripheral neuropathic pain is caused by a variety of diseases such as diabetes, shingles, trauma or diseases of the nervous system. Pain sensations may be described as hot, burning, throbbing, shooting, stabbing, sharp, cramping, aching, tingling, pins and needles etc.
Your doctor will have explained the reason for prescribing gabapentin capsules to you.
This medicine has been prescribed to you and should not be given to anyone else.
Gabapentinoids 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, when it is appropriate to stop, and 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.
2. What you need to know before you take Gabapentin
Do not take Gabapentin if:
- you have had an allergic reaction or are allergic to gabapentin or similar medicines or to any of the ingredients (listed in section 6)
Warnings and precautions
Talk to your doctor or pharmacist before taking Gabapentin
- 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
- before taking this medicine, tell your doctor if you have ever abused or been dependent on alcohol, prescription medicines or illegal drugs; it may mean you have a greater risk of becoming dependent on Gabapentin
- If you have myasthenia gravis (a disease causing muscle weakness) because this medicine may make your symptoms worse
Talk to your prescriber before taking this medicine 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.
- have previously suffered from withdrawal symptoms such as agitation, anxiety, shaking or sweating, when you have stopped taking alcohol or drugs.
- 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.
- you are using the medicine for reasons other than prescribed
- you have made repeated, unsuccessful attempts to quit or control the use of the medicine
- when you stop taking the medicine you feel unwell, and you feel better once taking the medicine again
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 or reduce your dose. 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.
Gabapentinoids 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 gabapentinoids, may increase the risk of addiction. Overuse and misuse can lead to overdose and/or death.
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.
Important information about potentially serious reactions
Serious skin rashes including Stevens-Johnson syndrome, toxic epidermal necrolysis and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in association with gabapentin. Stop using gabapentin and seek medical attention immediately if you notice any of the symptoms related to these serious skin reactions described in section 4.
Read the description of serious symptoms in section 4 of this leaflet
Under ‘Contact your doctor immediately if you experience any of the following symptoms after taking this medicine as they can be serious’ 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.
Children
Use of gabapentin is not recommended in children under 6 years of age.
Other medicines and Gabapentin
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including herbal remedies and those you have obtained without a prescription.
antacids containing aluminium and magnesium may cause decreased absorption of gabapentin
from the stomach. It is therefore recommended that gabapentin is taken about two hours after any antacid administration.
- Gabapentin is not expected to interact with other anti-epileptic drugs or the oral contraceptive pill.
- If you require an operation or visit to your doctor or dentist, always let them know if you are taking gabapentin.
- Gabapentin may interfere with some laboratory tests, if you require a urine test tell your doctor or hospital that you are taking gabapentin
- Medicines containing opioids or morphine may increase the effect of gabapentin capsules.
Gabapentin with food and drink
Food has no effect on the absorption or efficacy of Gabapentin
Pregnancy and breast-feeding
- 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.
- If you are breastfeeding or planning to breastfeed, ask your doctor or pharmacist for advice before taking this medicine.
- You should not stop your treatment without discussing this with your doctor.
Pregnancy
Gabapentin can be used during the first trimester of pregnancy if needed.
If you plan to become pregnant or if you are pregnant or think you may be pregnant, talk to your doctor straight away.
If you have become pregnant and you have epilepsy, it is important that you do not stop taking your medicine without first consulting your doctor, as this may worsen your illness. Worsening of your epilepsy may put you and your unborn child at risk.
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).
Contact your doctor immediately if you become pregnant, think you might be pregnant or are planning to become pregnant while taking Gabapentin. 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.
Fertility
There is no effect on fertility in animal studies.
Breast-feeding
Gabapentin, the active substance of 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.
Driving and using machines
Gabapentin can cause dizziness, drowsiness and tiredness. If affected, you should not drive or operate machinery
Gabapentin contains 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
Always take this medicine exactly as your doctor or pharmacist had told you. Check with your doctor or pharmacist if you are not sure. Do not take more medicine than prescribed.
- Your doctor will determine the dose that is appropriate for you.
- If you feel the dose is too strong or too weak for you, talk to your doctor or pharmacist.
- Your doctor may prescribe a different dosing schedule and/or dose if you have problems with your kidneys.
- Always swallow the capsules whole with plenty of water.
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.
The recommended dose is
Epilepsy
Adults and children over 12 years:
900 – 3600mg daily in three divided doses i.e. in the morning, in the middle of the day and in the evening. The maximum time between two successive doses should not exceed 12 hours in a three times daily schedule. Gabapentin can be taken with or without food.
Elderly
Elderly patients may require dosage adjustment by their doctor. If you have problems with your kidneys, speak to your doctor before taking this medicine.
Children 6-12 years of age
The recommended dose of gabapentin is 25 to 35 mg/Kg/day given in three divided doses i.e. one in the morning, one in the middle of the day and one in the evening. You should always follow your doctors instructions.
Neuropathic pain Adults (over 18 years of age)
Your doctor will usually build up your dose by starting you on 300mg once a day on day one, 300mg twice a day on day two and 300mg three times a day on day three. The dose may be increased to 3600mg each day given in three divided doses, i.e. in the morning, in the middle of the day and in the evening. Gabapentin can be taken with or without food.
If you think gabapentin is causing problems or alternatively if you experience complete pain relief, please talk to your doctor or pharmacist straight away.
Keep taking your capsules for as long as your doctor has asked you to.
If you have kidney problems or are receiving haemodialysis
Your doctor may prescribe a different dosing schedule and/or dose if you have problems with your kidneys or are undergoing haemodialysis.
If you take more Gabapentin than you should
If you or someone else accidentally take 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 the pack with you 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. Symptoms of an overdose are dizziness, double vision, slurred speech, drowsiness, loss of consciousness, and diarrhoea.
If you forget to take Gabapentin
If you miss a dose, just 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
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 prescriber 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. If you experience withdrawal effects, you should contact your doctor.
Withdrawal symptoms such as:
- trouble sleeping, headache, nausea, feeling anxious, diarrhoea, flu-like symptoms, convulsions, nervousness, depression, thoughts of harming or killing yourself, pain, sweating, and dizziness.
If you have any further questions on the use of this medicine, ask your doctor or pharmacist.
4. Possible Side Effects
Like all medicines, Gabapentin 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).
Tell your doctor immediately if you experience any of the following symptoms after taking this medicine. Although they are very rare, these symptoms can be serious. breathing problems, which if severe you may need emergency and intensive care to continue breathing normally.
persistent stomach pain, feeling sick and being sick (these may be symptoms of acute pancreatitis-swelling of your pancreas).
Serious or life-threatening allergic reaction that may affect parts of your body such as liver or blood cells and skin. You may or may not have a rash when you get this type of a reaction. Notify 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 the lip and tongue
- bruising or bleeding that is unusual
- yellowing of the skin or of the whites of the eyes
- severe fatigue or weakness
- unexpected muscle pain
- frequent infection
These symptoms may be the first signs of a serious reaction. A doctor should examine you to decide if you should continue taking Gabapentin.
- If you are on haemodialysis, tell your doctor if you develop muscle pain and/or weakness.
Other side effects include:
Very common side effects (affect more than one person in 10)
- Viral infection
- Feeling drowsy, dizziness, lack of coordination
- Feeling tired, fever
Common side effects (affects more than one person in 100)
- Pneumonia, respiratory infection, urinary tract infection, inflammation of the ear or other infections
- Low white blood cell count, decrease in white blood
- Anorexia (loss of appetite), increased appetite, increase in weight
- Anger towards others, confusion, fluctuation in mood, depression, anxiety, nervousness, difficulty with thinking.
- Convulsions, jerky movements, tremor, difficulty with co-ordination - Difficulty with speaking
- Difficulty sleeping, headache, loss of memory - Sensitive skin, pins and needles, decreased sensation - Increased, decreased or absent reflexes.
- Blurred vision, double vision, unusual eye movement
- Vertigo (a sensation of spinning)
High blood pressure, flushing or dilation of blood vessels
- Difficulty breathing, bronchitis, sore throat, cough, dry or runny 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
- Swelling in the legs and arms, difficulty with walking, weakness, pain, feeling unwell, flu-like symptoms
- Accidental injury, fracture, abrasion
Uncommon side-effects (affects more than 1 person in 1000)
- Decreased movement
- Swelling that may involve the face, trunk and limbs
- Allergic reaction such as hives
- Fall Abnormal blood test results suggesting problems with the liver or increases in blood creatine phosphokinsase
- Racing heartbeat
- Mental impairment
- Increase in blood glucose levels (most often observed in patients with diabetes)
- Agitation (a state of chronic restlessness and unintentional and purposeless motions)
- Difficulty in swallowing
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)
Not known: frequency cannot be estimated from the available data
- dependence and addiction (see section “How do I know if I am tolerant or addicted?”)
After marketing Gabapentin the following side effects have been reported
- Ringing in the ears
- Inflammation of the liver, yellowing of the skin and eyes
- Hallucinations
- Problems with abnormal movements such as writhing, jerking movements and stiffness
- Acute kidney failure
- Incontinence
- Increased breast tissue, breast enlargement
- Sexual dysfunction (including changes in your libido, ejaculation disorders and inability to orgasm)
- decreased in blood sodium levels
- Worsening of myasthenia gravis (a disease causing muscle weakness)
Adverse events following the abrupt discontinuation of gabapentin, anxiety, difficulty sleeping, feeling sick, pain, sweating, chest pain
- Decreased platelets (blood clotting cells)
- Breakdown of muscle fibers (rhabdomyolysis)
Anaphylaxis (serious, potentially life threatening allergic reaction including difficulty breathing, swelling of the lips, throat, and tongue, and hypotension requiring emergency treatment)
Drug Withdrawal
When you stop taking Gabapentin or after reducing your dose, 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.
Additionally in clinical studies in children, aggressive behaviour and jerky movements were reported commonly. Do not be alarmed by this list of side effects, most people take gabapentin without any problems.
Reporting of side effects
If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: 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
KEEP OUT OF THE SIGHT AND REACH OF CHILDREN.
Do not use this after the expiry date which is stated on the label. The expiry date refers to the last day of that month.
Do not store above 25°C. Store in the original package.
Do not throw away any medications via waste water or house hold 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 Athlone Capsules contains The active substance is gabapentin.
Gabapentin Athlone Capsules contain the inactive ingredients: lactose monohydrate, maize starch, talc and gelatin
The printing ink contains: shellac, black iron oxide (E172), soya lecithin and antifoam
The 100mg capsules contain the colouring titanium dioxide (E171).
The 300mg capsules contain the colourings titanium dioxide (E171) and yellow iron oxide (E172). The 400mg capsules contain the colourings titanium dioxide (E171), red iron oxide (E172) and yellow iron oxide (E172).
What Gabapentin Athlone looks like and contents of the pack
The name of your medicine is Gabapentin Athlone. Gabapentin Athlone hard capsules are available in three strengths:
Gabapentin Athlone100mg Capsules are opaque white hard gelatin capsules marked with GABA 100mg.
Gabapentin Athlone 300mg Capsules are opaque yellow hard gelatin capsules marked with GABA 300mg.
Gabapentin Athlone 400mg Capsules are opaque orange hard gelatin capsules marked with GABA 400mg.
Gabapentin Athlone Capsules are available in blister packs containing 100 capsules, with each blister strip containing 10 capsules.
Marketing authorisation holder and manufacturer
Kent Pharmaceuticals Limited, Connect 38, 1, Dover Place, Ashford, Kent, United Kingdom, TN23 1FB.
Distributed by:
Kent Pharmaceuticals Limited, Wotton Road, Ashford, Kent, TN23 6LL, U.K.
PL 08215/0150, PL 08215/0151 and PL 08215/0152
This leaflet was last updated March 2026.