Effects of Sustained-release Oral Sodium Nitrite on Postoperative Pain and Recovery Following Total Knee Arthroplasty

Effects of Sustained-release Oral Sodium Nitrite Supplementation on Pain-related Outcomes and Peri- and Postoperative Physiology in People Undergoing Unilateral All-component Revision Total Knee Arthroplasty

This study will determine whether a drug called sodium nitrite helps improve pain and post-operative recovery associated with knee replacement surgery.

The goal of this study is to examine the potential for oral sodium nitrite supplementation to reduce postoperative pain and inflammation and improve functional recovery in individuals undergoing unilateral revision total knee replacement. A sustained release formulation of sodium nitrite (40 mg) administered twice daily will be compared with placebo for a 30-day treatment period. Primary objectives are to evaluate pain and markers of functional improvement.

Inclusion Criteria:

• Male and female individuals aged 18-70
• Ambulatory with knee pain for greater than 6 months prior to surgery, and willing and able to comply with all study requirements will be considered eligible.

Exclusion Criteria:

• Severe hypertension (systolic blood pressure greater than or equal to 200 mmHg or diastolic blood pressure greater than or equal to 120 mmHg);
• BMI greater than 45 kg/m2;
• Active smoker or stopped smoking within 6 months of enrollment;
• Active local or systemic malignancy, such as lung cancer or leukemia;
• Cardiovascular disease resulting in dyspnea at rest;
• Peripheral neurovascular disease;
• Anemia;
• Hematological disease (eg, coagulopathy, sickle cell disease/anemia);
• Hemoglobin variant;
• Glucose-6-phosphate dehydrogenase deficiency;
• Methemoglobin reductase deficiency;
• Known sensitivity to nitrites;
• Liver disease;
• Use of phosphodiesterase type 5 inhibitors;
• Use of sildenafil (Viagra);
• Systemic treatment with antibiotics, immunosuppressants including corticosteroids, medications for migraine, allopurinol, tricyclic antidepressants, antihistamines, and/or nitrates currently or in the last month;
• Use of nitrovasodilators (e.g. GTN) within the last month;
• Use of protein pump inhibitors within the last month;
• History of substance abuse;
• Recent surgery or hospitalization (within last 6 months);
• Inability to swallow a pill;
• Failure to provide full consent;
• Involvement with a worker's compensation, personal injury, or other legal matter related to participant health.