Gabapentin (Neurontin®) belongs to a group of medications called anticonvulsants.
What is this medication used for?
Gabapentin is approved by Health Canada as an add-on medication (adjunct) to manage seizures in adults. Gabapentin is not approved by Health Canada for use in children and adolescents.
While not approved by Health Canada for these uses, there is evidence to support the use of gabapentin in adults with neuropathic pain, anxiety, restless legs syndrome, cannabis use disorder, and alcohol use disorder.
When the potential benefits outweigh risks, gabapentin may be prescribed “off-label” for children and adolescents. Learn more about off-label use:
Tell your doctor or pharmacist if you:
- Have allergies or bad reactions to a medication.
- Take or plan to take other prescription or non-prescription medications (including natural medicines). Some medications may interact with gabapentin. Your doctor may adjust doses or monitor for side effects.
- Have a history of severe respiratory problems, liver or kidney disease, heart disease, bowel obstruction, seizures, mood disorders, or head injury.
- Miss a menstrual period, are pregnant, breastfeeding, or planning a pregnancy.
- Use alcohol or street drugs. Taking gabapentin with certain substances may cause a bad reaction. Learn more at www.DrugCocktails.ca
When will this medication start to work?
For pain, alcohol use disorder, and cannabis use disorder, the effects of gabapentin may be experienced quickly, but full benefit is expected to be seen in 1-2 months after starting this medication. Continue taking this medication even if your symptoms do not improve immediately.
For restless legs syndrome and anxiety, gabapentin can start reducing symptoms within 2-4 weeks.
Talk with your doctor if you feel that gabapentin has not been helpful or if the side effects are too bothersome. Your doctor may recommend switching you to a different dose or medication.
How do I take this medication?
Take this medication as prescribed by your doctor. To help minimize the risk of side effects, your doctor will start you on a low dose, and gradually increase as needed. Typically, gabapentin is taken either at bedtime only or 2 to 3 times daily, with or without food.
Take this medication at the same time(s) every day. Continue taking this medication, even if it has worked to reduce or stop your symptoms. If you are using this medication for neuropathic pain, continue taking gabapentin on a regular basis to help prevent pain (rather than using it "as needed" for symptoms).
Possible common or serious side effects:
Side effects may be more common when first starting a medication or after a dose increase. Talk to your doctor, nurse, or pharmacist for help managing side effects or if a side effect concerns you.
- Dizziness, weakness or headache
- Drowsiness, difficulty concentrating or trouble sleeping
- Dry mouth, increased thirst
- Increased appetite and weight gain
- Nausea, vomiting, change in bowel pattern, stomach ache
- Swelling of the lower legs or feet
Contact your doctor immediately if you experience:
- Blurry vision, double vision or visual field loss
- Slow, shallow, or weak breathing
- Chest pain, or irregular heartbeat
- Signs of liver damage, including yellow-colored skin and eyes, unusually dark-colored urine or light-colored stools, severe upset stomach or abdominal pain
- Unexpected rash, fever or excessive sweating
- Unusual changes in mood or behavior such as ongoing sadness or thoughts of hurting yourself
- Seeing, hearing, or feeling things that are not there
What precautions should my doctor and I be aware of when taking this medication?
- If you are (or begin) taking any other prescriptions, over-the-counter medication, natural health product or supplement, check with your doctor or pharmacist to make sure there are no unsafe drug interactions.
- If you feel dizzy or drowsy during the daytime while taking this medication, do not drive a car or operate heavy machinery. Alcohol or cannabis use could make symptoms of dizziness or drowsiness worse. It is best to avoid alcohol or cannabis use while taking gabapentin.
What should I do if a miss a dose?
If you forget to take a dose of gabapentin, take the missed dose as soon as you remember. However, if it is within 4 hours of your next scheduled dose, skip the missed dose and continue regularly with your next scheduled dose. DO NOT double your next dose to try to 'catch up'.
How do I store this medication?
Keep this medication in the original container, stored at room temperature away from moisture and heat and protect from light. Keep this medication out of reach and sight of children.
How does this medication work?
Gabapentin works by blocking calcium channels in the brain. This indirectly alters the production of brain chemicals (called neurotransmitters) such as GABA, glutamate and certain peptides that reduce anxious feelings, pain signals, the urge to move your legs or cravings to use alcohol or cannabis over time.
What special instructions should I follow while using this medication?
Keep all your appointments with your doctor and the laboratory. Your doctor may order lab tests to check how you are responding to the medication and to monitor for side effects. Try to keep a healthy, well-balanced diet and exercise regularly.
Do not allow anyone else to use your medication. The medication could cause unwanted side effects in individuals who do not take gabapentin.
Attending counselling (as recommended by your doctor) increases the likelihood that this medication will help you continue to overcome anxiety or substance dependence.
Is this medication addictive?
Taking gabapentin may lead to physical and psychological dependence (such as being unable to sleep without medication) or abuse (taking more than prescribed). As the dosage and duration of treatment increases, the risk of dependence or abuse becomes higher.
If you have been taking gabapentin for a long period of time and suddenly stop, you may experience withdrawal symptoms such as sleep difficulties (insomnia) or return of anxiety. Talk with your doctor about how to safely lower the dose gradually to prevent withdrawal effects as your body adjusts to being without it.
How well does this medication work in children and adolescents?
Gabapentin has been shown to decrease cannabis and alcohol use in adult patients. In children and adolescents, gabapentin has been shown to be safe, however it has not been studied in cannabis and alcohol use disorder. Although there are limited studies evaluating gabapentin and its use in treating anxiety or restless legs syndrome, it has been reported helpful for the management of these conditions. Gabapentin has also been shown to improve symptoms of neuropathic pain associated with shingles (post-herpetic neuralgia), fibromyalgia or diabetes. Based on its safety data in children and adolescents, and efficacy data in adults, the potential benefits may outweigh its risks.
How long should I take this medication for?
Your doctor will discuss with you how long you may need to take this medication. If treatment is beneficial for cannabis or alcohol use disorder, your doctor may slowly reduce the dose until it can be stopped. For neuropathic pain, most people need to take gabapentin for at least 6 months as this allows time for symptoms to stabilize. After this time, you and your doctor can discuss the benefits and risks of continuing treatment. For treatment of anxiety or restless legs syndrome, if gabapentin has shown benefit for you and you tolerate it well, you may be asked to take it on an ongoing basis as continuing treatment decreases the chance that your symptoms will return. Do not increase, decrease or stop taking gabapentin without discussing it with your doctor, even if you are feeling better. If you stop taking gabapentin suddenly, your symptoms may return or you may have an unwanted reaction.
