Mirtazapine and Quetiapine as Treatment for Postoperative Sleep Disturbance After Fast-track Knee Replacement

Background After knee replacement surgery there is a loss of quantity and quality of sleep. Loss of sleep is associated with increased pain perception. Subsequently, patients use more analgesic medication and it takes them longer to fully recover from surgery. Low doses of the tetracyclic antidepressant mirtazapine and the neuroleptic quetiapine are nowadays off-label prescribed for insomnia and improve length and quality of deep sleep phases. Quetiapine and mirtazapine could improve sleep after knee replacement surgery and improve patient recovery. This placebo-controlled, randomized, double-blind study investigates the effect of quetiapine and mirtazapine on functional recovery after total knee arthroplasty.

Methods This is a prospective, single center, double-blinded randomized controlled trial. 165 patients with knee osteoarthritis scheduled for total knee arthroplasty will be randomly allocated to a low-dose quetiapine (LDQ), a low-dose mirtazapine (LDM) group or a placebo group. Outcomes will be evaluated at baseline, 2, 4, 6 and 12 weeks after surgery. Functional outcome after total knee arthroplasty is measured using a patient related outcome measure through the Oxford Knee Score (OKS). In order to measure postoperative sleep quality, patients will be monitored using the Leeds Sleep evaluation questionnaire (LSEQ). Furthermore, pain is registered using a visual analogue scale (VAS), weekly opioid use is monitored, and general health status is reported through the EQ-5D. Analyses will be conducted on an intention-to-treat basis using logistic and linear mixed regression models. This trial complies with the SPIRIT guidelines for randomized controlled trials.

Discussion This study will provide clinicians with evidence whether quetiapine contributes to rehabilitation of patients undergoing fast-track knee replacement surgery.