Duloxetine for Postoperative Pain After Knee Surgery

This trial explores whether duloxetine, a medication, can reduce pain and the need for opioids after knee replacement surgery. The study compares two groups: one receiving duloxetine and another receiving a placebo (a pill with no active medication). It aims to determine if duloxetine manages pain better than current treatments alone. Ideal candidates for this trial are those planning knee replacement surgery due to osteoarthritis and who have not previously used certain mental health medications. As a Phase 4 trial, duloxetine is already FDA-approved and proven effective, and this research seeks to understand how it benefits more patients.

The trial requires that you have not used SSRIs, SNRIs, or serotonergic drugs (except tramadol) in the past 6 months. If you are taking these medications, you would need to stop before participating.

Research has shown that duloxetine is generally safe and can help with pain after surgeries like knee replacements. Many studies have found that participants tolerated duloxetine well, experiencing few serious side effects. Most side effects were mild, such as nausea or fatigue. Since the FDA has already approved duloxetine for other uses, its safety profile is well-established. Therefore, using duloxetine for post-surgery pain is considered safe for most people.¹²³⁴⁵

Researchers are excited about duloxetine for managing postoperative pain after knee surgery because it offers a unique approach compared to standard treatments like opioids and NSAIDs. Duloxetine is typically used as an antidepressant and for nerve pain, but it has a different mechanism: it works by increasing levels of serotonin and norepinephrine in the brain, which can help modulate pain perception. This could potentially reduce reliance on traditional painkillers, which often come with significant side effects and addiction risks. Additionally, duloxetine is taken orally and can be started before surgery, potentially providing more comprehensive and sustained pain relief.

Studies have shown that duloxetine, which participants in this trial may receive, can effectively reduce pain and lower the need for strong painkillers after knee surgery. Research indicates that patients taking duloxetine feel less pain and can begin rehab exercises sooner. A review of several studies supports that duloxetine helps manage pain and reduces the need for opioids. However, some studies found no major differences between duloxetine and opioids in terms of pain control and function over a year. Overall, duloxetine has proven effective for managing pain after knee replacements.¹²³⁵⁶