Pilot Study: Oral Ketamine and Aspirin Control Pain Well in Total Knee Replacement

Researchers sought to better understand the safety and efficacy of oral ketamine and aspirin for pain management in patient’s having total knee replacement (TKR) surgery. In doing so, investigators at the Hospital for Special Surgery in New York, New York, conducted a yet unpublished pilot study that included 22 patients. Based on their initial findings, the investigators plan to pursue a larger randomized clinical trial to compare this combination therapy for pain control in TKR surgery with standard opioid treatment.

To be included in the pilot study, patients had to be in good health and have no history of opioid use. Study participants received aspirin and ketamine orally 4 times daily until discharge up to 72 hours after surgery and were monitored and assessed for pain with standard pain scales.

Of the 22 patients in the study, 18 reported no side effects from the treatment, although 2 patients reported dizziness. Two other patients withdrew from the study early because they needed more pain relief. Ages of the study participants ranged from 47 to 81 years.

“There’s been considerable research and effort into reducing opioid consumption after elective surgeries, and specifically after knee replacement,” explained the study’s principal investigator, Michael Ast, MD, in a press release. “Many people consider knee replacements the most painful elective surgery someone can have.”

The researchers aimed to find effective pain management medication that patients would be able to take on their own at home. This is of particular relevance to patients who receive a total knee replacement because those patients are typically hospitalized for 1 day but are experience the highest level of postsurgical pain between days 3 and 10 of recovery.

“Aspirin and ketamine work together synergistically on the body’s pain receptors,” he continued. “This allows [prescribers] to use relatively low doses of the ketamine, which also aids in preventing the dissociative feelings, even at larger doses.”

“If this treatment proves to be as effective as we hope it’s going to be, we can imagine a world where — even after something as painful as knee replacement surgery — patients go home with only a few opioid pills to take if needed, rather than a more typical amount of 25 or 30 pills that are often provided today,” Dr Ast concluded.

This article originally appeared on Clinical Pain Advisor