 More than half of people with advanced cancer and pain will need strong opioids, and these in combination with non-opioid pain medicine can produce acceptable analgesia in 70 – 90 percent of cases. A Cochrane review updated in 2016 concluded that morphine is effective in relieving cancer pain. Side-efffects of nausea and constipation are rarely severe enough to warrant stopping of treatment. Sedation and cognitive impairment usually occur with the initial dose or a significant increase in dosage of a strong opioid, but improve after a week or two of consistent dosage. Antiemetic and laxative treatment should be commenced concurrently with strong opioids, to counteract the usual nausea and constipation. Nausea normally resolves after two or three weeks of treatment but laxatives will need to be aggressively maintained.
