Case Study : the use of subcutaneous clonidine for pain relief in complex cancer pain

Abstract

Pain is a common symptom in the terminal phase of a cancer patient, and the World Cancer Declaration sets a target for universally available pain control by 2025. Cancer pain can be complex to manage due to the different pathological mechanisms occurring, particularly as it advances and is progressively resisting current analgesia. This case report focuses on the use of clonidine in the palliative care setting, where opioid and non-opioid approaches to analgesia have not controlled the intensifying pain. Sharing this study aims to further the experience base of its utility in complex cancer pain management. The a2A-adrenergic receptor agonist, clonidine, is increasingly being recognised as an effective adjuvant medication for pain and agitation in patients in end-of-life care. This is due to its anti-nociceptive properties and non-opioid action. Evidence of its use in a palliative setting, and relevant pharmacokinetic safety profile, is limited. However, a recent retrospective study in the UK has shown it to be a promising drug due to being well tolerated and its symptomatic benefits. Clonidine was titrated in response to reported and observed pain behaviours, to serve as an adjuvant to opioids. It was noted that there was a significant decrease in opioid usage in correlation with an increased dosage of clonidine. Despite the complicating factor of COVID-19, the patient reported a clinical benefit of clonidine in terms of their pain and comfort. Review of the patient's integrated Palliative Care Outcome Scale indicated maintained scores with introduction of clonidine compared to prior use of opioids. This report highlights the positive clinical experience of the use of clonidine for complex cancer pain as a 'rescue' analgesia and a continuous subcutaneous infusion. Further high-level research to establish its role and efficacy in this field is recommended.