Effect of Gabapentin Enacarbil on Opioid Consumption and Pain Scores

Opioids are effective analgesics, but cause side effects including sedation, respiratory
depression, low blood pressure, nausea, and constipation. Gabapentin enacarbil, which is a
FDA approved drug for post herpetic neuralgia (nerve pain related to shingles) and restless
leg syndrome, may decrease your need for narcotics and thus decrease the risk of side
effects. The investigator hopes this study will determine if gabapentin enacarbil decreases
opioid consumption and pain after surgery.

Patients having elective hip and knee surgery will be asked to participate in the study.
Patients will be randomized to Gabapentin enacarbil 600mg twice per day for 5 days or Placebo
twice per day for 5 days.

One day prior to surgery the patient will take Gabapentin enacarbil 600mg or placebo 600mg
twice a day with meals. On the day of surgery, the patient will take Gabapentin enacarbil
600mg or placebo 600mg two hours before the surgical procedure. Six hours after the
completion of surgery, the patient will receive Gabapentin enacarbil 600mg or placebo 600mg.
If the patient is sent home, the patient will be given 6 Gabapentin enacarbil 600mg or
placebo 600mg pills to take home along with instructions. However, if the patient remains
hospitalized, on the first day after the surgery, the patient will have pain assessed in the
morning using a numerical rating score. The patient's quality of recovery will be evaluated
using a questionnaire and the patient will receive Gabapentin enacarbil 600mg or placebo
600mg twice a day with meals. The second and third day the patient is in the hospital, the
patient will have pain assessed in the morning using a numerical rating score and the patient
will receive Gabapentin enacarbil 600mg or placebo 600mg twice a day with meals. Then, three
months after surgery, the patient will receive a phone call to follow-up with possible pain
or discomfort the patient may be feeling.