GENERIC NAME: Gabapentin

COMMON BRANDS: Neurontin, FusePaq Fanatrex, Gabarone, Gralise

Gabapentin is an oral prescription anti-epileptic drug, also called an anticonvulsant. It belongs to a class of drugs called anticonvulsants. The exact mechanism of action of this drug is not known, but it structurally resembles the neurotransmitter “gamma-aminobutyric acid (GABA)”. (Neurotransmitters are natural chemical substances present in the central nervous system by which nerves communicate with each other). The studies suggest that this structural similarity of gabapentin is related to its mechanism of action.

What is Gabapentin used for?

Gabapentin along with other medications used in the treatment of epilepsy to control partial seizures (convulsions). This drug cannot cure epilepsy, but it works to control seizures as long as you continue to take it.

Gabapentin is also used to relieve nerve pain in adults for a condition called postherpetic neuralgia (pain that occurs after shingles).

How to use Gabapentin?

This medication comes with a medication guide. Read and follow all the instructions carefully. If you have any query, seek advice from your doctor.

Take this medicine only orally as directed by your doctor. Do not alter your dose or take it more frequently or for a longer duration than prescribed as doing so may increase the chance of side effects.

The dose of the drug based on your medical condition and response to treatment, and for children, the dose based on the child’s weight. It is essential to follow your doctor’s dosing instructions exactly to minimize side effects. During the start of therapy, your doctor may advise you to take the first dose at bedtime and gradually increase your dose so your body can adjust to the medication.

For patients with epilepsy who are taking gabapentin three times a day, do not let more than 12 hours pass between doses. This medicine works best if a constant amount of drug remains in the blood.

If you are taking an antacid containing magnesium or aluminium may interfere with the absorption of gabapentin. Therefore, it is better to take this drug at least 2 hours after taking the antacid.

Do not discontinue using this medicine without a doctor’s advice. Some conditions can become worse when the drug is suddenly stopped, to avoid this complication your doctor may reduce your dose gradually.

Only use the brand of this drug that your doctor prescribed to you. Different brands (such as immediate-release, sustained-release, enacarbil sustained-release) are absorbed in the body differently.

What are the side effects of Gabapentin?

The most common side effects observed with this drug are dizziness, drowsiness, memory loss, unsteadiness, lack of coordination, difficulty speaking, viral infections, tremors, double vision, fever, unusual eye movements, and jerky movements. If any of these side effects remain or worsen, inform to your doctor or pharmacist promptly.

Get emergency medical assistance right away if you have serious side effects, like slow/shallow breathing, swelling of the hands/ankles/feet.

Few people who take anticonvulsants may experience mood or behavior changes, depression or anxiety, suicidal thoughts/attempts. Inform your doctor right away if you or your family member notice any unusual/sudden changes in your mood, thoughts, or behavior.

Serious and life-threatening allergic reaction to this drug is rare, consult your doctor if you notice symptoms like skin rashes, hives, fever, swollen glands, swollen lips and tongue, yellowing of your skin, unusual bruising or bleeding, weakness, sudden muscle pain, frequent infections.

This is not a full record of all possible side effects. If you mark other effects not listed above, contact your doctor or pharmacist.

What are the precautions while taking Gabapentin?

Share your medical history with your doctor or pharmacist before taking gabapentin, especially of kidney disease, mental/mood problems (like depression, thoughts of suicide), breathing problems, use/abuse of drugs/alcohol.

Before taking gabapentin, notify your doctor if you are allergic to it or if you have any other allergies as this drug may cause severe allergic reactions.

Avoid driving, using any machinery, or doing anything that requires alertness or clear vision until you can do it safely, as this drug may cause dizziness, drowsiness (sleepiness), vision changes or trouble with thinking.

Gabapentin in some people may cause agitation, irritability, or abnormal behaviors, like hostility and anxiety (restlessness). Children are more prone to these side effects, notify your doctor if you observe any of these effects.

In pregnancy, this medication should be used only when the benefits outweigh the risk. Gabapentin passes into breast milk. Consult your doctor before breastfeeding.

What are the drug interactions of Gabapentin?

Gabapentin may interact with other drugs, vitamins, or herbal products you may be taking. To avoid such interactions, your doctor manages all of your medications carefully. Share with your doctor about all the products you are using.

Gabapentin may interact with orlistat, morphine, aluminium hydroxide and magnesium hydroxide. Discuss with your doctor, if you are using these products.

Avoid using products that cause drowsiness like alcohol, marijuana, drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), antihistamines (such as cetirizine, diphenhydramine) and muscle relaxants. Notify your doctor if you are using these products.

Check the labels on all your medicines carefully (like an allergy or a cough and cold products) as they may contain ingredients that make you drowsy. Ask your pharmacist about using these products safely.

Avoid using gabapentin with other medications that contain gabapentin (including gabapentin enacarbil).

What are the forms and strengths of Gabapentin?

Generic: Gabapentin.
Form: Oral capsule.
Strengths: 100mg, 300mg, 400mg.

Brand: Neurontin.
Form: Oral capsule.
Strengths: 100mg, 300mg, 400mg, 600mg , 800mg.

Form: Oral solution.
Strengths: 250mg/5mL.

What is the dosage of Gabapentin?

For Postherpetic Neuralgia:

Adult dosage (18–64 years):

Brand: Neurontin

Day 1: 300mg orally once a day
Day 2: 300mg orally 2 times a day
Day 3: 300mg orally 3 times a day
Maintenance: 300 to 600mg orally 3 times a day
Maximum dose: 3600 mg orally per day (in 3 divided doses)
The maximum time interval between doses in the 3 times a day schedule should not exceed 12 hours.

Brand: Gralise

Titrate gradually to 1800 mg/day orally; take once a day with the evening meal.
Day 1: 300mg orally once a day
Day 2: 600mg orally once a day
Days 3-6: 900mg orally once a day
Days 7-10: 1200mg orally once a day
Days 11-14: 1500mg orally once a day
Maintenance dose: Starts on day 15 orally once a day 1800mg.

Dosing considerations:

Gralise tablets swell in gastric fluid and slowly release gabapentin.

For Partial Seizures:

Adult dosage (18–64 years):

Brand: Neurontin

Initial: 900mg/day (300mg, three times per day, spaced evenly throughout the day). Your doctor may increase your dose to 2400–3600mg per/day.

For Restless Legs Syndrome (Off-label):

Adult dosage (18–64 years):

100-300mg orally 2 hours before bedtime on the first day; increase the dose every two weeks until symptom relief (range 300-1800mg/day)

For Cocaine Withdrawal (Off-label):

Adult dosage (18–64 years):

800-1500mg/day orally in divided doses for up to 9 months

For Insomnia (Off-label):

Adult dosage (18–64 years):

Up to 1800mg orally at bedtime for up to 9 weeks

For Diabetic Neuropathy (Off-label):

Adult dosage (18–64 years):

900mg/day orally initially; may increase gradually every third day to 1800-3600mg/day

For Tremors in Multiple Sclerosis (Off-label):

Adult dosage (18–64 years):

1200-1800mg/day orally as monotherapy

For Hot Flashes-Cancer Related (Off-label):

Adult dosage (18–64 years):

200-1600mg orally every day in a divided dose for 4-8 weeks

Dosing Modifications:

For Renal impairment:

CrCl >60 mL/min: 300-1200mg orally three times per day.

CrCl 30-60 mL/min: 200-700mg every 12 hours.

CrCl 15-29 mL/min: 200-700mg every day.

CrCl <15 mL/min: 100-300mg every day.

Hemodialysis (CrCl <15 mL/min): Administer supplemental dose (range 125-350mg) post-hemodialysis, after each 4 hours dialysis interval; further dose reduction should be in proportion to CrCl (eg, CrCl of 7.5 mL/min should receive one-half daily post-hemodialysis dose)

For Partial-Onset Seizures:


Children (0–2 years):

The use of this drug below three years of age is not recommended as safety and efficacy has not been established.

Children  (3–11 years):

Typical starting dosage: 10–15mg/kg/day, divided into three doses, spaced evenly throughout the day. The dose may be increased if needed up to 50mg/kg/day(maximum dose).

Children (ages 12–17 years):

Typical starting dosage: 300mg, three times per day, spaced evenly throughout the day. This can increase to 2,400–3,600mg per day.

Geriatric (65 years and above):

The dose of the drug based on your kidney function as with the age kidney function decrease and your body may metabolize this drug more slowly. At the start of therapy, the doctor may prescribe you lowe dose to avoid too much of gabapentin in your body which can be dangerous.


TheMedPharma has made every effort to make sure that all the information is factually correct, comprehensive, and up-to-date. However, this website should not be considered as a substitute for the advice, knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or licensed health care professional before taking any medication. The drug information contained herein is subjected to changes if required. The lack of warnings or other information for a given drug does not mean that the drug or its combination is safe, effective or appropriate for use in all patients.