In young adults, Neurontin is usually started at 300 milligrams (mg) per day, and the dose is increased by 300 mg every 1 to 3 days to the highest dose that can be taken without persistent side effects.

The recommended dosage as add-on therapy (when Neurontin is taken with another seizure medicine) is 900 to 1800 mg daily, but many people need to take more for maximum seizure control. Doses are generally given three times a day (one-third each time), with no more than 12 hours between doses.

People over age 65 generally require a lower dosage and longer intervals between doses.

The doctor occasionally may suggest checking the level of Neurontin in the blood to see whether it falls within the range that is usually considered appropriate for the dosage taken (called the therapeutic range). A therapeutic range has not been established for Neurontin, however, so whether the amount prescribed needs to be adjusted generally depends on whether seizures or side effects are occurring.