Do I Need to Stay on the Same Brand of Gabapentin?

Gabapentin capsules, tablets, and oral solution are used along with other medications to help control certain types of seizures in people who have epilepsy.

Gabapentin Neurontin
Gabapentin Neurontin

Gabapentin capsules, tablets, and oral solution are also used to relieve the pain of postherpetic neuralgia (PHN; the burning, stabbing pain or aches that may last for months or years after an attack of shingles).

Gabapentin extended-release tablets (Horizant) are used to treat restless legs syndrome (RLS; a condition that causes discomfort in the legs and a strong urge to move the legs, especially at night and when sitting or lying down).

Gabapentin is in a class of medications called anticonvulsants. Gabapentin treats seizures by decreasing abnormal excitement in the brain. Gabapentin relieves the pain of PHN by changing the way the body senses pain. It is not known exactly how gabapentin works to treat restless legs syndrome.

Most people do not have to stay on the same brand of gabapentin as there’s very little difference between brands.

Talk to your doctor if you have been asked to switch to a different brand and are worried about that.

If your epilepsy has been hard to control in the past and the brand you’re now taking is working well for you, your doctor may recommend you stay on the same one.

Forms and strengths

Generic: Gabapentin

  • Form: oral capsule
  • Strengths: 100 mg, 300 mg, 400 mg

Brand: Neurontin

  • Form: oral capsule
  • Strengths: 100 mg, 300 mg, 400 mg

Dosage for postherpetic neuralgia

Adult dosage (ages 18–64 years)

  • Typical starting dosage: Day 1, 300 mg; day 2, 600 mg (300 mg two times per day, spaced evenly throughout the day); day 3, 900 mg (300 mg, three times per day, spaced evenly throughout the day). Your doctor may further increase your dosage after day 3.
  • Maximum dosage: 1,800 mg per day (600 mg, three times per day, spaced evenly throughout the day)

Child dosage (ages 0–17 years)

Dosage for people younger than 18 years has not been established.

Senior dosage (ages 65 years and older)

Your kidney function may decrease with age. Your body may get rid of this drug more slowly. Your doctor may start you on a lower dose so that too much of this drug does not build up in your body. Too much of the drug in your body can be dangerous. Your doctor may change your dose based on how well your kidneys are working.

Dosage for partial-onset seizures

Adult dosage (ages 18–64 years)

Typical starting dosage: 900 mg per day (300 mg, three times per day, spaced evenly throughout the day). Your doctor may increase your dose to 2,400–3,600 mg per day.

Child dosage (ages 12–17 years)

Typical starting dosage: 900 mg per day (300 mg, three times per day, spaced evenly throughout the day). The usual maintenance dose is 900–1,800 mg per day, divided into three doses daily. Your doctor may increase this dose to 2,400–3,600 mg per day.

Child dosage (ages 3–11 years)

Typical starting dosage: 10–15 mg/kg/day, divided into three doses, spaced evenly throughout the day. Your child’s doctor may increase the dosage to meet your child’s needs.

Child dosage (ages 0–2 years)

Dosage for people younger than 3 years has not been established.

Senior dosage (ages 65 years and older)

Your kidney function may decrease with age. Your body may get rid of this drug more slowly. Your doctor may start you on a lower dose so that too much of this drug does not build up in your body. Too much of the drug in your body can be dangerous. Your doctor may change your dose based on how well your kidneys are working.

How Long Does it Take Gabapentin to Work?

It can take several weeks for gabapentin to reach its full effect, but this depends on the condition being treated.

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking gabapentin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with or without food as directed by your doctor. Dosage is based on your medical condition and response to treatment. For children, the dosage is also based on weight.

If you are taking the tablets and your doctor directs you to split the tablet in half, take the other half-tablet at your next scheduled dose. Discard half tablets if not used within several days of splitting them. If you are taking the capsules, swallow them whole with plenty of water.

It is very important to follow your doctor’s dosing instructions exactly. During the first few days of treatment, your doctor may gradually increase your dose so your body can adjust to the medication. To minimize side effects, take the very first dose at bedtime.

Gabapentin is approved to treat:

      • Nerve pain
      • Some types of seizures
      • Restless legs syndrome (RLS)

It also depends on your individual response to the drug. The time gabapentin takes to work is not the same for everyone.

The effective dose of gabapentin is also very different for each person. It may vary from 300 mg per day to up to 3,000 mg per day.

Another reason gabapentin takes time to work is that the dose is usually started low and gradually increased over time to reach an effective dose.

For example, when used to relieve nerve pain, the initial dose may be started at 300 mg and increased by 300 mg daily over several days, gradually reaching up to 600 mg three times per day. Studies for nerve pain treatment show that pain relief may begin within 1 week, with the maximum effect reached after about 4 weeks.

Gabapentin is in a class of medications called anticonvulsants. It is not completely known how this drug works. When used to treat a type of seizure disorder, called a partial onset seizure, gabapentin decreases the abnormal activity in the brain that causes the seizures. When used to treat nerve pain, or neuralgia, following a herpes zoster (shingles) infection, gabapentin may reduce the response to painful stimuli. It is unknown how gabapentin relieves symptoms of restless legs syndrome.

Even though it may take up to 4 weeks to get the full effects of gabapentin, it is important not to stop taking it suddenly. That could cause withdrawal symptoms such as:

      • Anxiety
      • Insomnia
      • Nausea
      • Pain

If you are taking gabapentin to control seizures, stopping suddenly may increase your risk of a seizure.

Common side effects of Gabapentin

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:

    • Feeling sleepy, tired or dizzy
    • Feeling sick (nausea)
    • Being sick (vomiting)
    • Diarrhoea
    • Mood changes
    • Swollen arms and legs
    • Blurred vision
    • Dry mouth
    • Difficulty getting an erection
    • Weight gain
    • Memory problems
    • Headaches
    • Getting more infections than usual

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.