Pregabalin decreases pain, speeds movement in knee replacement patients

The drug pregabalin administered before and after knee replacement surgery, significantly decreased patient pain while increasing and expediting mobility after surgery, according to a study by Asokumar Buvanendran, MD, director of Orthopedic Anesthesia and associate professor of Anesthesiology at Rush University Medical Center, Chicago.

The study was presented at the American Society of Anesthesiologists meeting in San Francisco on October 14.

Total knee replacement (TKR) is one of the most prevalent and painful orthopedic surgical procedures. With an increasing aging population, the number of knee replacements performed in the United States increased by 69 percent from 1997 to 2005, with an estimated 314,000 TKR procedures being done each year in the United States by 2010. While extremely successful in ultimately ending or minimizing knee pain and disability, the procedure can cause postoperative knee stiffness, mechanical failure, and severe, chronic pain.

Buvanendran conducted the study with 60 TKR patients in two groups. One group received 300 milligrams of pregabalin (an anti-convulsant) two hours before surgery and 150 milligrams twice a day for 14 days following surgery. The other patients were given placebos at the same intervals. Both groups received pain medication through an epidural catheter during surgery and after surgery through a patient-controlled device.

The study found a “significant decrease” between the pregabalin and placebo groups in pain medication consumption in the 32 hours following surgery. The pregabalin group also consistently reported pain levels between two and four (on a scale of one to 10, with “10” being most severe) following surgery, and used less pain medication at all time points.

In addition, the patients' knee range of motion (ROM) following surgery was higher in the pregabalin patients at hospital discharge: 84 degrees compared to 76 degrees among non-pregabalin patients. At 83 degrees a patient can climb stairs. Typically, it takes a patient a full week to reach that level, Buvanendran said.

Administration of pregabalin “decreased postoperative analgesic requirements while improving function,” Buvanendran said, noting that the ROM improvements are “especially important.”

“When you can walk up and down stairs, it makes a huge difference in patient life quality,” he said. In addition, the improved range of motion allows patients to complete necessary post-surgical rehabilitation more quickly.

Editor's Note: Research for this study was funded by a grant from Pfizer, Inc., which markets pregabalin under the brand name Lyrica.