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Completed

NCT Number: NCT05023278

The Use of Venlafaxine in Reducing Pain in Primary Total Knee Replacement

Patients experience pain after their knee replacement surgery - and some may continue to experience persistent pain long after their knee replacement surgery. Traditional pain management strategies reply on pain medication such as opioids for pain control. However, these drugs do not work well for pain associated with movement or the the nerve pain (tingling, electrical sensations) after surgery. In addition, opioids are associated with significant side effects such as nausea, vomiting, respiratory depression, depression, cognitive dysfunction and risk of persistent opioid use. Neuropathic pain medications, such as venlafaxine are effective in managing nerve pain. Recent studies also support its potential role in acute pain management. Here, we propose a prospective randomized clinical trial 1) to evaluate the efficacy of Venlafaxine in reducing pain intensity and opioid consumption at post-operative day 1 (POD1) and 1- week after surgery, and 2) to examine whether the use of Venlafaxine will reduce the incidents of chronic postsurgical pain in TKA patients at 3-month time point.

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Key information

Conditions

Acute Pain Chronic Pain Knee Pain Chronic Nervous System Diseases Neuralgia Neurologic Manifestations Neuromuscular Diseases Neuropathic Pain Pain Pathological Conditions, Signs and Symptoms Peripheral Nervous System Diseases Signs and Symptoms

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of California San Francisco

San Francisco, California, 94143, United States

About this study

Patients meeting the inclusion criteria will be randomized to receive either Venlafaxine extended release (ER) 37.5 mg/d or a placebo on the day of surgery and continue the treatment for 7 days after surgery. The primary outcomes include pain severity score (numeric rating scale, NRS) and consumption of morphine miligram equivalent (MME) at 24 hours. The secondary outcome will measure MME and NRS at postoperative day 7. In addition, the disability scale and perceived function 3 months after surgery will be compared to the baseline level by using PROMIS (Patient-Reported Outcomes Measurement Information System)10 Global Health, KOOS, JR. (Knee injury and Osteoarthritis Outcome Score Short Form), and VR-12 (Veterans RAND 12 Item Health Survey) Scale.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • adult (male and female) subjects aged 18 to 75,
  • English speaking,
  • are scheduled for primary total knee arthroplasty with planned spinal anesthesia with saphenous peripheral nerve block at the adductor canal.

Exclusion criteria

  • general anesthesia,
  • hepatic & renal failure,
  • history of diabetic peripheral neuropathic pain,
  • chronic opioid use,
  • concurrent use of antidepressants, triptans, and/or linezolid,
  • allergy to the study medications,
  • prior knee surgery,
  • BMI > 40,
  • bleeding disorders,
  • history of recent falls,
  • concurrent benzodiazepine use.

Treatment and study plan

Venlafaxine 37.5 MG

Drug

venlafaxine 37.5mg daily for 7 consecutive days.

Other names: SNRI analgesia

Placebo

Drug

placebo filled pill daily for 7 consecutive days.

Other names: control

Primary outcomes

  1. Cumulative 24 hour total opioid consumption

    Time frame: 24 hours

    morphine miligram equivalent

Secondary outcomes

  1. Pain numeric rating scale at 24 hours post operatively

    Time frame: 24 hours

    Pain Scores will be measured on the Numerical Rating Scale (NRS), the score ranges from 0-10, zero indicating no pain and 10 indicating the worst pain.

  2. Pain severity and interference at 7 days post operatively

    Time frame: 7 days

    The Brief Pain Inventory (BPI) assesses the severity of pain and its impact on functioning.The BPI scale defines pain as follows:1 - 4 = Mild Pain. Worst Pain Score: 5 - 6 = Moderate Pain. Worst Pain Score: 7 - 10 = Severe Pain.

  3. Pain severity and interference at 3 months post operatively

    Time frame: 3 months

    The Brief Pain Inventory (BPI) assesses the severity of pain and its impact on functioning.The BPI scale defines pain as follows:1 - 4 = Mild Pain. Worst Pain Score: 5 - 6 = Moderate Pain. Worst Pain Score: 7 - 10 = Severe Pain.

  4. Functionality at 7 days postoperatively

    Time frame: 7 days

    Knee injury and osteoarthritis outcome score short form: Patient-Reported Outcomes Measurement Information System (PROMIS), item health survey. The PROMIS Global-10 is a 10-item patient-reported questionnaire in which the response options are presented as 5-point (as well as a single 11-point) rating scales. The average Score is 50 points, with a standard deviation of 10 points. Higher scores indicate a healthier patient.

  5. Functionality at 7 days postoperatively

    Time frame: 7 days

    Knee injury and osteoarthritis outcome score short form, veterans RAND 12 (VR12) item health survey. The results of the VR-12 are summarized as two scores - a Mental Component Score (MCS) and a Physical Component Score (PCS). The United States population average PCS and MCS are both 50 points. The United States population standard deviation is 10 points. Therefore, each increment of 10 points above or below 50 corresponds to one standard deviation away from the population average.

  6. Functionality at 3 months postoperatively

    Time frame: 3 months

    Knee injury and osteoarthritis outcome score short form: Patient-Reported Outcomes Measurement Information System (PROMIS), item health survey. The PROMIS Global-10 is a 10-item patient-reported questionnaire in which the response options are presented as 5-point (as well as a single 11-point) rating scales. The average Score is 50 points, with a standard deviation of 10 points. Higher scores indicate a healthier patient.

  7. Functionality at 3 months postoperatively

    Time frame: 3 months

    Knee injury and osteoarthritis outcome score short form, veterans RAND 12 (VR12) item health survey. The results of the VR-12 are summarized as two scores - a Mental Component Score (MCS) and a Physical Component Score (PCS). The United States population average PCS and MCS are both 50 points. The United States population standard deviation is 10 points. Therefore, each increment of 10 points above or below 50 corresponds to one standard deviation away from the population average.

  8. Opioid consumption at 7 days postoperatively

    Time frame: 7 days

    morphine miligram equivalent

  9. Opioid consumption at 3 months postoperatively

    Time frame: 3 months

    morphine miligram equivalent

Sponsors and collaborators

Lead sponsor

University of California, San Francisco

Other

Collaborators

  • Orthopedic Research and Education Foundation

Registry information

Official study title

The Use of Venlafaxine in Reducing Acute Post-Surgical Pain and Opioid Consumption in Primary Total Knee Replacement

Important dates

Study start
2021
Primary completion
2025
Study completion
2025
First posted
Aug 26, 2021
Registry last updated
May 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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