Key points
- In most patients cancer pain can be controlled; there is no need to endure it, and enduring it is no virtue [1].
- Tell your doctor your pain as a number from 0 to 10 so a medicine matching its severity can be started [1].
- Morphine at the right dose, under a doctor's care, is the main medicine for moderate to severe cancer pain [1, 2]; fear of addiction should not leave you suffering.
One important step: report the pain and take the medicine on schedule
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Give your pain a number
Tell your doctor how bad your pain is from 0 (no pain) to 10 (worst pain), where it is and when it gets worse. The starting medicine is chosen on that basis [1].
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Prevent constipation
Constipation is a common side effect of morphine [1]. Ask your doctor to prescribe a laxative from the first day, and drink enough water.
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Ask for palliative care from the start
The palliative care team helps control pain, breathlessness, nausea and anxiety, and is not only for the last days. In a trial, patients with advanced lung cancer who received this care from diagnosis had better quality of life, less depression and longer survival [4].
When should I contact a doctor?
Tell your doctor the same day about:
- Pain that your current medicines do not control or that keeps you awake at night
- Severe drowsiness, confusion or slow breathing after starting or increasing a painkiller [1]
- Constipation for more than 3 days, or nausea and vomiting that stop you taking your medicine
- New or worsening back pain with weakness or numbness in the legs, or trouble controlling urine or bowels: this is an emergency (cancer emergencies (Persian)).
Frequently asked questions
Will I become addicted to morphine?
Morphine and similar medicines are recommended for moderate to severe cancer pain unless there is a reason not to use them [2]. If the body gets used to the medicine over time (physical dependence), the doctor lowers the dose slowly when stopping it so withdrawal symptoms do not occur [1]; this is not the same as addiction. If you have a history of addiction, tell your doctor; pain can still be treated, and the doctor will work with a pain or addiction specialist [2].
If I take morphine now, will it stop working later?
What about opium or self-medication?
Taking opium or painkillers on your own means an unknown dose and a risk of interactions, and opium itself causes cancer (Does opium cause cancer?). Treat pain with a prescribed medicine at a known dose.
How is bone pain from metastases treated?
As well as painkillers, single-session radiotherapy is recommended for pain from bone metastases, and bone-strengthening medicines (bisphosphonates) also help prevent and treat bone pain [1].
Notes for doctors (for physicians)
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WHO 2018 (strong recommendations). At initiation, NSAIDs, paracetamol and opioids alone or in combination according to pain severity; a mild analgesic alone is not enough for moderate or severe pain. For maintenance any opioid may be used; where oral use is possible, oral immediate- or modified-release morphine at regular doses, with oral immediate-release morphine as rescue (moderate-quality evidence). When the oral or transdermal route is not possible, subcutaneous is preferred to intramuscular. With physical dependence, taper gradually. Adjuvant corticosteroids when indicated, for the shortest time. For bone metastases, bisphosphonates and single-fraction radiotherapy (high-quality evidence) [1].
ASCO 2023. Offer opioids for moderate to severe pain related to cancer or its treatment unless contraindicated; start PRN at the lowest effective dose, reassess early and titrate frequently; in substance use disorder, work with palliative, pain or addiction teams; monitor for and prevent adverse effects [2]. Details of titration and opioid rotation are in the ESMO 2018 guideline [3].
Regimens and doses
Oral immediate-release morphine (chronic cancer pain)
Moderate to severe cancer pain in adults; titration and maintenanceCycle length: Every 4 hours
Moderate to severe cancer pain in adults; titration and maintenance
| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Immediate-release morphine | 2 to 20 mg | Oral (or subcutaneous/intravenous) | Regularly every 4 hours; increase the dose as needed |
The oral dose is about twice the equivalent parenteral dose. The modified-release dose is first titrated with the immediate-release form; modified-release tablets are not used for breakthrough pain and must not be crushed. Use caution and lower doses in renal or hepatic impairment and in older or frail patients. Side effects: nausea (especially at the start), constipation, drowsiness; high doses cause respiratory depression and hypotension. Abrupt withdrawal after long use causes withdrawal symptoms [1].
Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.
Scientific evidence
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Scientific evidence
1 itemEarly palliative care for patients with metastatic non-small-cell lung cancer
References
4 referencesShow all references, 1 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1
- 2
- 3Management of cancer pain in adult patients: ESMO Clinical Practice Guidelines
- 4Early palliative care for patients with metastatic non-small-cell lung cancer
This page is based on reputable scientific sources and was last updated on 27 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
