Gabapentin dosage, forms, and strengths

Check our best Gabapentin prices

The dosages listed are general guidelines; your healthcare provider may adjust your dose based on individual health factors.

Gabapentin is a generic prescription drug that is FDA-approved as a treatment for partial-onset seizures or nerve pain from shingles. Extended-release gabapentin enacarbil is also FDA-approved to treat restless legs syndrome. 

Gabapentin is frequently prescribed off-label for many other conditions, such as diabetic peripheral neuropathy, fibromyalgia, other types of nerve pain, and alcohol withdrawal.

Gabapentin dosage for partial-onset seizures

Gabapentin is used along with other drugs to control partial-onset seizures in adults and children 3 years of age or older. As an adjunctive therapy, gabapentin is used along with other antiseizure medications. The standard dosage is 300 to 600 mg taken three times daily. The maximum daily dose is 3,600 mg daily.

Gabapentin dosage for nerve pain due to shingles (postherpetic neuralgia)

Healthcare professionals also use gabapentin to treat postherpetic neuralgia, that is, neuropathic pain due to shingles (herpes zoster). Standard dosages are the same as they are for partial-onset seizures.

Gabapentin dosage for neuropathic pain

Gabapentin is most frequently prescribed off-label to treat nerve pain (neuralgia) due to a variety of causes, including nerve damage (neuropathy), diabetic nerve damage (diabetic neuropathy), compression, or irritation. Patients take up to 3,600 mg daily.

Gabapentin dosage for fibromyalgia

Healthcare providers also use gabapentin off-label to reduce fatigue, provide pain relief, and improve sleep in patients with fibromyalgia. The standard dose is 600 mg twice daily with 1,200 mg at bedtime. Because fibromyalgia symptoms worsen at night, the dose of this medicine is doubled in size at bedtime. Dosages are tapered by 300 mg daily when it’s time to discontinue treatment.

Gabapentin dosage for alcohol withdrawal

Gabapentin is used off-label for people with alcohol use disorder, particularly those in the maintenance phase of alcohol abstinence. There is usually a loading dose (an initial higher dose) of 1,200 mg. Afterward, the recommended dosage is 600 mg every 6 hours on day 1 or 400 mg 3 times daily for 1 to 3 days. Treatment only lasts a few days. After that, the dose is reduced to 300–600 mg daily for up to four to seven days.

How should gabapentin dosage be adjusted for people with kidney issues?

For FDA-approved indications (postherpetic neuralgia and partial-onset seizures), gabapentin doses may be reduced both in their amount and frequency:

• Creatinine clearance of 30-59 ml/min: 200–700 mg twice per day

• Creatinine clearance of 16-29 ml/min: 200–700 mg once per day

• Creatinine clearance of 15 ml/min or less: 100–300 mg once per day 

• Hemodialysis: dose is dependent on estimated creatinine clearance; a supplemental dose of 125–350 mg is given after dialysis 

Because fibromyalgia, alcohol withdrawal, and diabetic neuropathy are off-label uses, there are no standard dosage reductions for those with kidney problems. The dosage will be determined by a healthcare provider. 

Gabapentin safety info

Gabapentin is a relatively safe prescription drug. Because it’s a central nervous system depressant, the most common side effects are drowsiness, dizziness, coordination problems, and fatigue. People taking gabapentin should avoid driving a car, operating heavy machinery, or engaging in hazardous activities until they know how the drug affects them.

Gabapentin is contraindicated in anyone who has had an allergic reaction to the drug. Allergic reactions to gabapentin can be severe and include anaphylaxis, angioedema, and a potentially life-threatening reaction that involves many of the vital organs in the body.

Because gabapentin slows down breathing, doctors use it cautiously in people who have trouble breathing, lung conditions, or who take other drugs that affect breathing. 

Suicidal thoughts are an uncommon but possible side effect, so patients and their caregivers should be alert to signs of new or worsening depression, suicidal behaviors, or other unusual changes in mood or behavior.

It isn’t known if gabapentin can harm an unborn baby. People who are pregnant should consult a healthcare provider before taking gabapentin. 

The most significant gabapentin drug interactions are with other drugs that slow down the nervous system (CNS depressants). Besides worsening the sedative effects of gabapentin, these drug interactions could cause serious breathing problems (respiratory depression). These drugs include alcohol, cannabinoids, opioids, sedatives, antihistamines, anxiety medications, and drugs that treat seizures.

Stopping gabapentin suddenly can bring on withdrawal symptoms, so don’t stop taking doses until talking to the prescriber. The healthcare provider will probably gradually reduce the dose for a week or longer, but the tapering schedule will vary. There are no standardized tapering schedules for FDA-approved indications, but there are several tapering guidelines for people with kidney disease or people who are being treated for fibromyalgia or alcohol withdrawal. 

How to take gabapentin

Gabapentin is usually taken by mouth three times per day with or without food. In special circumstances, such as when the drug is first started or in patients with kidney problems, gabapentin is taken less frequently. If you have epilepsy, do not allow more than 12 hours to pass between doses.

• Swallow the tablet or capsule whole with a glass of water. 

• Some tablets can be divided into two doses. Use the second half as the next dose. Discard any unused half-tablet after 28 days.

• If it’s too difficult to swallow the capsule, the patient or a caregiver can carefully open the capsule and sprinkle the contents into a small cup of water, juice, or apple sauce.

• Always measure liquid gabapentin with a graduated oral syringe or medicine cup. Shake the closed bottle well before measuring a dose. 

• If you take an antacid containing aluminum or magnesium, wait at least two hours before taking a gabapentin dose.

• Store gabapentin tablets or capsules at room temperature (59˚–86˚F), away from heat, moisture, and direct light. 

• Store the oral liquid in the refrigerator (36˚–46˚F). Do not freeze. 

Gabapentin dosage FAQs

How long does it take gabapentin to work?

For most conditions, it typically takes one to two weeks after starting gabapentin to notice improvements in symptoms. That’s because people initially start with a low dose. The dosage gradually increases in amount and frequency to the recommended maintenance dosage. 

What happens if I miss a dose of gabapentin?

If you miss a dose of this medicine, take the missed dose as soon as you remember. Take the next dose at its scheduled time. If it is almost time for the next dose, skip the missed dose and take the next dose at its scheduled time. Do not take extra medicine to make up for a missed dose. 

For partial-onset seizures, ask the doctor, pharmacist, or other healthcare professional for instructions about how to manage a missed dose. In patients with epilepsy, missing a dose for longer than 12 hours increases the risk of seizures.

What can be used instead of gabapentin?

Depending on the reason for use, gabapentin alternatives include anticonvulsants, analgesics, tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), and selective serotonin and norepinephrine reuptake inhibitors (SNRIs).

Can gabapentin dosage be different for managing different conditions?

The average doses of this medicine vary by condition, but the dosing frequency is usually three times daily. Dosing frequency may be different at the start of therapy.

Gabapentin dosage for pets

Veterinarians frequently prescribe gabapentin to treat anxiety, seizures, or chronic pain in pets and large animals. The recommended dosage depends on the type of animal and their body weight. For example, the recommended dosage for a cat experiencing seizures is 5-10 mg per kilogram of body weight every 12 hours, but the recommended dosage for dogs with the same condition is 10-20 mg per kilogram of body weight every 8 hours. 

Sources:

• Gabapentin, StatPearls

• Gabapentin: Clinical use and pharmacokinetics in dogs, cats, and horses, Animals (Basel) (2023)

• Gabapentin solution prescribing information, DailyMed (NIH National Library of Medicine)

• Gralise drug summary, Prescriber’s Digital Reference (PDR)

• Neurontin gabapentin capsule/tablet/solution prescribing information, DailyMed (NIH National Library of Medicine)