Why are opioid pain medicines used in cancer pain management?

Opioids attach to specific receptors in the brain and spinal cord, reducing how strongly pain signals are felt. Cancer pain may come from the tumour, surgery, inflammation, nerve irritation, or other treatment effects. The choice of medicine, route, and dose depends on the pain pattern, other medicines, kidney and liver function, and the person's goals.

Sleepiness, nausea, dizziness, itching, and constipation can occur. Constipation is common enough that a bowel plan may be prescribed alongside the opioid. Tolerance and physical dependence can develop with continued use; these are different from addiction, which involves harmful compulsive use. Never share medicine, change the dose, or stop suddenly without clinical advice.

Take the medicine exactly as directed and keep a record of pain relief and side effects. Ask about regular and breakthrough doses, constipation prevention, alcohol, driving, sleeping medicines, and safe storage. Tell the team about all medicines and supplements. If pain remains poorly controlled or side effects interfere with eating, walking, or alertness, the regimen can often be adjusted.

Seek urgent medical help for very slow or difficult breathing, inability to wake, blue or grey lips, severe confusion, or a suspected overdose. Contact the prescribing team promptly for repeated vomiting, severe constipation, fainting, or pain that suddenly becomes much worse. Follow the emergency plan given with your prescription.

What type of pain is this medicine intended to treat? When should I take a breakthrough dose? What bowel plan should I use? Which medicines or drinks should I avoid? How will we review the dose and reduce it safely when pain improves?