Dosing of Dexamethasone in Chronic Cancer Pain

Abstract

Submit Manuscript | http://medcraveonline.com Corticosteroids are a versatile group of drugs widely being used in cancer for a range of indications. They are used in conditions with proven evidence of their role like metastatic spinal cord compression [3], superior vena caval syndrome, raised intracranial pressure, bowel obstruction as well in those conditions lacking definitive role of steroids like chronic cancer pain, nausea, fatigue, and anorexia. They are also used to prevent immediate pain flare up following radiotherapy in vertebral metastases [4]. In relation to chronic cancer pain, it is being used in bony pain, visceral pain due to obstruction of hollow viscus, organ capsule distension, neuropathic pain due to infiltration or compression of neural structures and metastatic spinal cord compression. The possible role of steroids in every step of nociception: transduction, transmission, modulation and pain perception has been raised though the exact mechanism of action remains unclear. The mechanisms suggested include-inhibition of collagenase expression (key enzyme involved in tissue destruction during inflammation), reduction of pro-inflammatory cytokines and stimulation of lipotropin synthesis (inhibition of eicosanoid production). Hence steroids are most effective in inflammatory pain. They also inhibit spontaneous discharges from injured nerve and modulate neuroimmune interactions thereby decreasing neuropathic pain.However, corticosteroids are often "double edged swords"; though they provide rapid symptomatic relief they also have side effects that are dose and time dependent. Hence, clear guidelines regarding the "when, what, how, how much and how long" of steroid therapy must be established. Among the steroids, dexamethasone has been used more frequently because of its low mineralocorticoid activity, longer half-life, higher potency, availability of oral and parenteral formulations, higher glucocorticoid activity, 7 times more anti-inflammatory effect than prednisone and affordability. Numerous groups have assessed the utility of dexamethasone in cancer pain using a wide range of doses without arriving at conclusive objective evidence regarding its efficacy (Table 1). Dosing of DexamethasoneDexamethasone has been used in various dose ranges in chronic cancer pain patients despite paucity of randomised controlled trials and weak evidence of its efficacy. Although there are some studies which report benefit of steroids in pain control their validity is limited because of small sample size. A recent meta-analysis by Hawood et al. [11] was done to evaluate the efficacy of corticosteroids in treating cancer related pain in adults [11]. Fifteen studies that met the inclusion criteria were identified but only 6 studies were included in meta-analysis study for pain intensity as insufficient data was available for other studies. The studies which assessed dexamethasone described a dose range of 8 mg to 20 mg orally mostly as twice daily dosing. Also there is lack of an appropriate parenteral dose for dexam...