Gabapentin Dosage

Gabapentin is usually taken by mouth three times per day.

Take as directed

Gabapentin oral capsule is used for short-term or long-term treatment. The length of treatment depends on what condition it’s being used to treat. It comes with serious risks if you don’t take it as prescribed.

If you stop taking it suddenly or don’t take it at all:

  • For seizures: This can increase your risk of status epilepticus, which is a medical emergency. With this condition, short or long seizures occur for 30 minutes or more. If your doctor decides to reduce your dose or have you stop taking gabapentin, they will do this slowly. Your dose will be reduced or your treatment stopped over the course of at least one week.
  • For postherpetic neuralgia: Your symptoms won’t improve.

If you miss doses or don’t take it on schedule: Your medication may not work as well or may stop working completely. In order for this drug to work well, a certain amount needs to be in your body at all times.

If you take too much: You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

  • double vision
  • slurred speech
  • tiredness
  • loose stools

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 911 or go to the nearest emergency room right away.

What to do if you miss a dose: If you forget to take your dose, take it as soon as you remember. If you remember just a few hours before the time for your next dose, then only take one dose. Never try to catch up by taking two capsules at once. This could result in dangerous side effects.

How to tell if the drug is working: You should have fewer seizures. Or you should have less nerve pain.

In special circumstances, such as when the drug is first started or in patients with kidney problems, gabapentin is taken less frequently.

      • Take your medicine as directed. The dose may change until the most effective dose amount is reached.
      • If you have epilepsy, do not allow more than 12 hours to pass between doses.
      • Gabapentin can be taken with or without food.


    • Swallow the tablet whole with a glass of water. Do not crush, break, or chew it.
    • If you break a tablet into two pieces, use the second half as your next dose. Discard any unused half-tablet after 28 days.


    • Swallow the capsule whole with a glass of water. Do not open, crush, or chew it.
    • 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 and give the dose that way.

Oral liquid

    • Measure the oral liquid with a syringe or medicine cup that has millimeter markings. Gabapentin oral suspension usually comes with a 12 ml dosing syringe.
    • Shake the closed bottle well before each use.
    • Remove the child-proof cap from the bottle.
    • Make sure the syringe adapter has been pushed into the bottle opening. If not, fully insert the syringe adapter into the bottle opening.
    • Push the syringe plunger all the way down to the tip.
    • Insert the syringe tip into the adapter.
    • Turn the bottle and syringe upside down.
    • Slowly draw out enough liquid to the correct milliliter mark.
    • Turn the bottle back to the upright position.
    • Remove the syringe and place the tip in the mouth.
    • Slowly empty the contents into the mouth and swallow.
    • Securely fasten the child-safety cap back on the bottle.

Missed dose

    • If you miss a dose of gabapentin, 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.
    • If you are taking gabapentin for seizures, ask your doctor or pharmacist for directions on how to handle a missed dose.

When taking gabapentin, you may want to consider the following safety and effectiveness tips:

    • Before taking gabapentin, please read the Medication Guide that comes with it. Ask your pharmacist for a copy if you do not have one.
    • Store the medicine in a closed container 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 the solution.
    • Unless directed by a doctor, do not take gabapentin with alcohol or medicines that cause drowsiness.
    • If you take an antacid containing aluminum or magnesium such as Maalox, Mylanta, or Gaviscon, wait at least two hours before taking a gabapentin dose.
    • When taking gabapentin as a liquid, use the metered syringe or cup supplied with the medicine to accurately measure the dose. If you lose the syringe or cup, your pharmacy can provide a replacement at no cost.
    • In an emergency when you can’t replace a lost measuring device, you can temporarily use a kitchen measuring spoon to take a dose of gabapentin oral suspension, but NEVER use a spoon that you eat with or a measuring cup. One full teaspoon is nearly equal to 5 ml of liquid. One full tablespoon equals about 15 ml of liquid.
    • If you are taking the oral liquid, ask your pharmacist for the correct milliliter dose.
    • For each dose, record the time in a diary or schedule to ensure that the next dose is not given too early or too late.
    • If taking gabapentin causes an upset stomach, try taking it with food.
    • If breastfeeding, ask your doctor about taking gabapentin.
    • Gabapentin can slow your thinking, decrease coordination, and cause drowsiness, so do not drive, operate machinery, or engage in dangerous activities if you feel tired, dizzy, or slow.

Gabapentin is highly lipophilic but not bound to plasma proteins, showing linear pharmacokinetics and not demonstrating any significant protein binding or liver metabolization. It has an oral bioavailability of greater than 90%, independent of dose. Generally, patients achieve steady-state plasma levels within 24 to 48 hours. There is no clinically significant effect in administration with food nor on the extent of absorption or elimination. The elimination half-life of the drug is approximately 6.5 hours. Gabapentin readily crosses the blood-brain barrier. It is primarily excreted renally, with no active metabolites. Dosage adjustment is necessary for patients with renal impairment. Pregabalin does not induce or inhibit CYP enzymes. Also, none of the CYP enzyme inhibitors alter its pharmacokinetics as a consequence.

  • Initial treatment with Gabapentin is usually started with one dose of 300 mg per day and later increases the frequency to 3 times a day and dosage up to 4800 mg per day. The recommendation is to start the first dose in the evening and then take the drug three times a day.
  • Usually, the effects are apparent in the first week of treatment but sometimes take about a month for significant improvement.
  • Taper the dose over more than seven days to discontinue the medication.

For Partial Seizure

  • 300 to 1200 mg 3 times per day by mouth
  • Max: 3600 mg per day 

For Post-Herpetic Neuralgia

  • 300 to 600 mg 3 times per day by mouth
  • Max: 1800 mg per day

For Neuropathic Pain

  • 300 to 1200 mg 3 times per day by mouth
  • Max: 3600 mg per day

For Fibromyalgia

  • 400 to 800 mg 3 times per day by mouth
  • Max: 2400 mg per day

Renal Dosing

Adjust the dose amount and frequency.

  • Creatinine clearance of 30 to 60: 200 to 700 mg twice per day
  • Creatinine clearance of 16 to 29: 200 to 700 mg once daily
  • Creatinine clearance of 15: 100 to 300 mg once daily
  • Creatinine clearance of less than 15: 125 to 350 mg as a supplement

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