Background and rationale: Chronic pain is the most feared symptom in palliative care (PC) patients. While paracetamol is effective for mild to moderate pain and useful when used in combination with “weak opioids,” it is not certain that there is sufficient continuing benefit when used in conjunction with “strong” opioids for moderate to severe pain to justify the additional medication burden.

Although there have been several studies describing opioid-sparing effects of paracetamol, there have been only a handful in patients with advanced cancer and pain despite strong opioids. A 2013 critical review concluded that the role of paracetamol in management of cancer pain remains controversial.1 We conducted a series of n-of-1 trials to test the feasibility of using this methodology to obtain the per patient effectiveness of paracetamol in providing additional analgesia to regular opioids in people with advanced cancer experiencing moderate to severe pain.