Does Duloxetine Reduce Sub-Acute Pain After Knee Arthroplasty?

Phase 4

Completed

Brief Summary: We are investigating the impact of duloxetine ("Cymbalta"), a serotonin and norepinephrine reuptake inhibitor, on pain after total knee arthroplasty (TKA). Specifically, the investigators will determine whether duloxetine, 60 mg daily for 2 weeks, reduces pain scores 2 weeks after TKA.

Recruitment & Eligibility

Inclusion Criteria

Patients with osteoarthritis scheduled for primary tricompartmental total knee arthroplasty with a participating surgeon
Age 25 to 75 years
Planned use of regional anesthesia
Ability to follow study protocol
English speaking (primary outcome obtained via telephone call and secondary outcomes include questionnaires validated in English only)
Patients planning on being discharged home or to a rehabilitation center that has agreed to participate

Exclusion Criteria

Concurrent use of duloxetine or other SNRIs, MAOIs, Tricyclic antidepressants, triptans (sumatriptan, rizatriptan, naratriptan, zolmitriptan, eletriptan, almotriptan, frovatriptan), lithium, buspirone, St. John's Wort
Hepatic insufficiency
Renal insufficiency
Patients younger than 25 years old and older than 75
Patients intending to receive general anesthesia
Allergy or intolerance to one of the study medications
Patients with an ASA of IV
Chronic gabapentin/pregabalin use (regular use for longer than 3 months)
Chronic opioid use (taking opioids for longer than 3 months)
Patients with major prior ipsilateral open knee surgery

Arm && Interventions

Group	Intervention	Description
Control	Placebo	Patients will receive 0mg of duloxetine
Duloxetine	Duloxetine 60mg	Patients will receive 60mg of duloxetine per dose. 1 capsule will be taken preoperatively. Starting on postoperative day (POD) 1, patients will take one capsule once a day until end of POD14.

Primary Outcome Measures

Name	Time	Method
NRS Pain With Ambulation at 2 Weeks	2 weeks after surgery	When considering the pain in the knee in which you are having/had surgery, on a scale of 0-10, with 0 being no pain and 10 being pain as bad as you can imagine, how would you describe your level of pain in the last 24 hours during ambulation?

Secondary Outcome Measures

Name	Time	Method
Total Daily Opioid Use (mg Oral Morphine Equivalents)	POD 1	Total daily opioid use (including PO, PCEA, IV, subcutaneous, IV push) in mg oral morphine equivalents on POD 1.
Nausea Severity	POD 1	Nausea severity measured using Likert scale ranging from 0 (none) to 10 (severe).