Opiates No Better at Easing Knee Osteoarthritis Pain

By Lila Abassi — Feb 12, 2016
A systematic review of controlled clinical trials reveals that opioid analgesics are not superior to non-steroidal anti-inflammatory drugs, or NSAIDs, in treating the pain associated with knee osteoarthritis.
knee arthritis via shutterstock knee arthritis via shutterstock

Anyone that has osteoarthritis of the knee can attest to how painful the condition can be. In fact, it's the most common cause of disability in the United States, and in conjunction with rheumatoid arthritis it affects nearly 8.6 million Americans. More than 600,000 knee replacements are performed each year with the demand increasing as the baby boomers age and obesity keeps rising.

Treating osteoarthritis, or OA, entails the following:

  • control pain and swelling
  • minimize disability
  • improve the quality of life
  • educate the patient about his/her role in disease management

The major medications used in the pharmacological management of OA include analgesics, such as acetaminophen; non steroidal anti-inflammatory drugs, or NSAIDs, which are also analgesic; and steroid injections into the joint space. In those individuals in whom acetaminophen and NSAIDs are not effective the next step in pharmacological treatment is opioid narcotics, such as Vicodin and Percocet, which obviously have their own set of baggage.

Use of opioid analgesics is limited to patients with moderate to severe pain in whom other interventions have failed. Many patients with OA are over 65 years of age and some are much older. In older adults the use of opioid analgesics for noncancer pain is discouraged due to increased sensitivity to adverse side effects, particularly sedation, confusion and constipation.

In the face of the opiate abuse epidemic in this country, doctors are facing increased pressure to not prescribe these analgesics.

Prescribing opiates, however, may not benefit the patient any more than NSAIDs for pain relief. According to a systematic review of 17 randomized controlled trials published in the journal, Osteoarthritis and Cartilage, revealed that NSAIDs and opioids provided similar pain relief in OA patients.

Patients who failed NSAIDs and are considering opioids should be aware that the pain relief from opioids is likely to be no greater than the pain relief they had with NSAIDs, but may provide an extra chance before considering total knee replacement, according to the study s senior author Elena Losina, PhD, professor of orthopedic surgery at Brigham and Women s Hospital and Harvard Medical School, Boston, Massachusetts, as reported in Medscape Medical News. Our hypothesis was that opioids would provide a greater amount of analgesic benefits, and we were surprised that we did not see such a difference.

The results, however, are encouraging for the physician who is placed in an ethical dilemma, as he/she can effectively treat a patient s pain as opposed to feeling guilty for potentially contributing to a lethal addiction crisis. At least to some extent, we know that non-narcotic analgesia is not inferior to opiate analgesics.

Life is not so simple. Opioids may not work better in relieving OA pain, but NSAIDs have their own baggage, and it can be bad. Some of the more serious side effects of this class of drugs include ulcers, gastrointestinal bleeding, kidney failure (especially with chronic use), liver failure, or prolonged post-surgical bleeding. So there will be many patients for whom opioid analgesics will be the only option for pain relief.

Clinical judgement should always be at the forefront of prescribing medications and also knowing when total knee replacement surgery is the next best answer.