A unique combination of commonly prescribed pain medications is more effective than conventional methods for controlling postoperative pain in patients recovering from total knee- or hip-replacement surgery, according to a UC Irvine College of Medicine study.

The study found that patients taking a specific combination of analgesic drugs during recovery reported feeling less pain and had a significantly reduced need for opioid drugs like morphine. In addition, patients on this pain-treatment program recovered more quickly, allowing them to shorten their hospital stays.

The study was conducted by Dr. Harry Skinner, professor and chair of orthopedic surgery, and results appear in the February issue of the American Journal of Orthopedics.

In devising the therapy, Skinner sought to find better relief for the extremely painful procedures that accompany total knee- and hip-replacement surgeries. During these procedures, many patients are given opioids to alleviate suffering. Opioids, such as morphine, have side effects that limit their efficacy, such as nausea, constipation and disorientation.

To lessen pain and reduce the need for opioids, Skinner prescribed patients a pain-treatment protocol using an around-the-clock treatment of commonly prescribed medicines that address different ways the central nervous system processes pain. These drugs included acetaminophen, which is used in over-the-counter pain-relief drugs like Tylenol; Vioxx®, an anti-inflammatory, Cox-2 inhibitor drug; and tramadol, which blocks a key area of the brain’s response to pain.

“By themselves, these three drugs provide good relief of mild to moderate pain, but when taken together, they each address different sites in the central nervous system that process pain,� Skinner said. “This multidrug approach shows great promise in aiding recovery and providing effective pain relief.�

As part of this pain-treatment protocol, Skinner also prescribed a local anesthetic and another anti-inflammatory drug for a 24-hour post-surgery period, and patients had the option of receiving on-demand opioids during their overall recovery.

Skinner studied two groups of knee- and hip-replacement surgery patients. One group received his pain-treatment protocol, and another was given conventional pain treatments. The patients were asked to rate their pain levels based on a numeric scale (0 equals no pain; 10 is worst possible pain), with a rating of 4 or below considered acceptable.

Those receiving the pain-treatment protocol reported less pain when polled two days after surgery and also on the day they were discharged. Patients on the pain-treatment protocol who also used on-demand opioids reported the most comfort, with a full 87 percent of them rating their pain at 4 or below 48 hours after surgery.

Those in the pain-treatment protocol group who used opioids used them three-times less often during the 48 hours after surgery than those in the conventional-treatment group, and their opioid usage was practically nonexistent by the time they were discharged. At discharge, more than 90 percent of the patients under the pain-treatment protocol reported pain scores of 4 or below, compared with less than 70 percent of the conventional group. Those under the pain-treatment protocol receiving knee replacements stayed in the hospital an average of one less day, with hip-replacement patients staying on average a half-day less.

The results of this study have been corroborated by the Press-Ganey survey scores of Dr. Skinner’s patients on pain control, which put his evaluations in the 99th percentile nationwide in pain control when compared to doctors in 839 hospitals.

“Treating pain has become an important part of a physician’s duties, and more effective, safer methods to help patients recover more comfortably should be developed,� Skinner said. “This type of pain-management protocol has the potential to be used in other surgery specialties.�

Dr. Ellen Y. Shintani, a pharmacist at UCI Medical Center, assisted with the study. Vioxx® is manufactured by Merck & Co., Inc.

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