Phantom limb pain treatment with mirtazapine: A case series

Objectives: To pilot the efficacy of mirtazapine for relief of phantom limb pain (PLP); to correlate the putative drug mechanism with theoretical PLP mechanisms; and to develop a rationale for further study of mirtazapine in this population. Design: Open-label case series. Subjects/Patients: Four individuals with PLP for at least 3 months after amputation. Methods: All subjects received oral mirtazapine between 7.5 and 30 mg/day. An 11-point numeric rating scale (0 to 10) measured pain intensity and relief during monitored outpatient follow-up visits. Results/Discussion: Mirtazapine use improved the PLP experienced by these subjects by at least 50%. Subjects with PLP-related sleeping difficulties reported the greatest pain relief concomitant with improved sleep quality. One subject was able to eliminate the use of a selective serotonin reuptake inhibitor antidepressant while using mirtazapine for PLP and depression without change in mood or affect. Mirtazapine enhances noradrenergic and serotonergic activity and may modulate PLP by central mechanisms. Current concepts of the proposed pathophysiology of PLP and the hypothetical impact of mirtazapine are discussed. Conclusion: Mirtazapine may be an effective treatment for PLP that can also potentially enhance sleep and mood. This information provides preliminary reinforcement for more formal, controlled studies concerning mirtazapine use in PLP.