Nortriptyline in knee osteoarthritis (NortIKA Study): study protocol for a randomised controlled trial

BackgroundOsteoarthritis (OA) is a common cause of pain and disability. Currently available analgesics are often insufficiently effective or have unacceptable adverse effects. Tricyclic antidepressants may offer a useful centrally-acting analgesic. Nortriptyline is a readily-available, cheap and comparatively well-tolerated tricyclic antidepressant.Methods/DesignWe will conduct a parallel group, two-arm, participant and investigator-blinded, …