This new once-daily formulation of gabapentin is designed to swell in the gastric fluid and gradually release the active drug. A dose of 1,800 mg/d resulted in a statistically significant reduction in average daily pain scores compared with placebo and was generally well tolerated. This new gabapentin formulation is not interchangeable with other gabapentin products because of differing pharmacokinetic profiles. The tablets will be marketed in 300-mg and 600-mg dosage strengths and will be available later this year.