The Role of Tramadol in Cancer Pain Management Cancer is estimated to cause over 8 million deaths per annum – approximately 13%of deaths worldwide. (IARC 2012).Globally, 32 million people are living with cancer. Cancer pain is one of the most feared symptoms associated with the disease. Pain may be the first symptom to cause someone to seek medical advice that leads to the diagnosis of cancer and 30-50% of all people with cancer will experience moderate to severe pain. (Portenoy 1999). For patients with advanced cancer, 75% - 90% will experience pain which has a major impact on their quality of life (Wiffen 2013) Tramadol, is an analgesic medication that has been placed on the 2nd step of the ladder of the WHO Analgesic Ladder for the management of moderately severe cancer pain. (WHO 2016) Tramadol has a dual mechanism of action. It has µ opioid binding properties (acts like an opioid) and in addition inhibits the reuptake of serotonin and noradrenaline at the descending inhibitory pathways (hence its efficacy in some neuropathic pain conditions). Tramadol has therefore been found to be a useful drug in patients with cancer pain (both with nociceptive and neuropathic characteristics) (Arbaiza 2007; Duehmke 2009; Finnerup 2015) Morphine remains the drug of choice for the management of moderate to severe cancer pain. However, due to strict regulations in many developing countries it is not readily available. These strict licensing laws and regulations are barriers to the availability of strong opioids in these developing countries. Tramadol is the only readily available opioid analgesic medicine, as it has been placed on a lower schedule compared to potent opioids such as morphine, because of its low abuse potential. (Radbruch 2013). Hence doctors can readily prescribe tramadol to control moderate and severe cancer pain, especially when the pain has mixed characteristics (nociceptive and neuropathic). About 1/3 of patients with cancer pain have pain with neuropathic pain characteristics. (Grond 1999; Caraceni 1999). A recent review of literature has shown the efficacy of tramadol in the pharmacological management of neuropathic cancer pain (Vadalouca 2012). Only codeine and morphine are in the current WHO list of essential medicines in the opioid category. Codeine is also not readily available. There is currently an ongoing Cochrane Review on the role of tramadol with or without paracetamol for cancer pain management. (Wiffen 2017). For the several reasons given above, tramadol should be included in the WHO essential medicine list. Tramadol is effective, it has been in general use for the last 30 years in Asia and has a good safety record.

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Ramani Vijayan Senior Consultant and Professor Department of Anaesthesiology University Malaya Kuala Lumpur Malaysia