A case report of Milnacipran in phantom-limb pain

Abstract

Introduction Phantom-limb sensations are so commonly reported after an amputation that they are considered normal. Up to 10% of amputees might report severe pain leading to a significant occupational dysfunction. And it is often overlooked because of limited breakthrough in understanding of aetiology and limited treatment options. I present a case report of PLP showing good response to Milnacipran – a novel antidepressant (SNRI) with dual mechanism of action through serotonin and norepinephrine reuptake inhibition similar to TCAs. Discussion In this case, patient had phantom-limb sensations along with phantom-limb pain which responded fairly to Tramadol but showed good response to Milnacipran. Milnacipran has already been approved by FDA for Fibromyalgia due to its action on noradrenergic and serotonergic fibres in descending inhibitory pain pathways as noted by Barkin and Fawcett (2000). Milnacipran is a selective serotonin and norepinephrine inhibitor (SNRI), sharing the class with other drugs likes Duloxetine and Venlafaxine. Patients on TCAs may not tolerate high doses due to their wide range of side effects like sedation, dry mouth, and constipation; thus limiting their use in PLP. Unlike TCAs, it does not act much on cholinergic or histaminic receptors, thus has minimal side effects. Thus, a molecule like Milnacipran, acting selectively on serotonin and norepinephrine receptors and having an efficacy profile similar to TCAs but without adverse effects, may show promising results in PLP.