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Opioids are a type of medicine used to relieve moderate to severe pain. They may also be called opiates or narcotics, and are a type of analgesic (painkilling) drug. Opioids work in the brain and other parts of the body by attaching to pain receptors to block the feeling of pain. Some people with cancer need opioids for cancer-related pain.
Your cancer care team may prescribe opioids for increasing or severe pain. Cancer-related pain can be caused by the cancer itself or by cancer treatments.
Opioids should be prescribed and used with great care for several reasons:
However, it's important to know that not everyone who uses opioids will become addicted or misuse them. Opioids can be safely taken when used responsibly and as prescribed.
Your cancer care team will discuss safety precautions and answer questions or concerns you may have.
If you are taking opioids, here are some important tips:
Your cancer care team might ask you questions before prescribing opioids. They might ask who you live with, if anyone has a history of addiction, if children are in the home, or how your medications are stored. A low dose of opioids might be prescribed first and then changes can be made based on how you’re feeling. While taking opioids, you might need to have urine or blood tests to check opioid levels.
Taking too many opioids can slow a person’s breathing or even stop their breathing altogether. Other signs of opioid overdose include:
Naloxone (Narcan) is a medicine that blocks the effects of opioids in case of an overdose. Your cancer care team might suggest having naloxone (Narcan) available while you are taking opioids, especially if you are taking a high dose of opioids or are at a higher risk of overdose.
Some things that can increase a person’s risk of opioid overdose include:
Your doctor might prescribe Narcan to have on hand or direct you to where you can get it. All 50 states allow Narcan to be sold over the counter without a prescription. It comes as a nasal spray.
If you decide to keep Narcan on hand in case of an emergency, make sure whoever you live with knows where it is and how to use it. Your doctor, nurse, or pharmacist can show you.
Here are some of the opioids used in cancer care. Some of the more common brand names are in parentheses.
Opioids come in long-acting and short-acting forms.
Opioids that are called extended release (ER), long-acting (LA), controlled release (CR), and sustained release (SR) are all long-acting forms. This means they release a little bit of the medication over a longer period. They are often taken once or twice a day to treat chronic pain.
Immediate release (IR) opioids are short-acting forms and release their medicine quickly over a shorter period of time. These opioids are used to treat breakthrough pain. They might be taken several times a day depending on pain level.
There are pros and cons to long-acting and short-acting opioids. While long-acting opioids take longer to work, they provide relief for much longer. While short-acting opioids work quickly, they don’t provide relief for as long. A short-acting opioid might be used with a long-acting opioid to give steady relief.
Sometimes, the same opioid is used to treat both chronic and breakthrough pain. For example, morphine comes in different forms. Morphine sulfate immediate release (MSIR) is a short-acting form of morphine. Morphine sulfate controlled release (MS Contin) is a long-acting form of morphine. Someone might be prescribed both MSIR and MS Contin. It is important to know which you are taking and how often.
Some opioids are combined with non-opioids in one medication for better pain relief.
See Non-opioids and Other Drugs to Treat Cancer Pain for more on acetaminophen and NSAIDs (non-steroidal anti-inflammatory drugs) like aspirin and ibuprofen.
Oxycodone may be added to aspirin, acetaminophen, or ibuprofen. For instance:
Hydrocodone may be added to acetaminophen or ibuprofen. For instance:
If you’re taking a combination pain medicine, be sure you know what drugs are in each because some can interact with each other and might damage your organs. For example, both Tylenol and Percocet have acetaminophen in them. There is a limit to how much acetaminophen you should take in a day, so it’s important to know how much total acetaminophen you are taking.
Talk to your cancer care team if your medications aren’t relieving your pain. It may take a few adjustments to find the combination that works best for you. Do not change how much or how often you take pain medication without talking to your care team first. If changing the dose or frequency doesn’t work, they may prescribe a different medication or add a new one to what you’re already taking.
Learn more about developing a pain control plan with your cancer care team.
Some people need to increase the dose of their pain medicine over time to get the same relief as they did before at a lower dose. This may be because the pain has increased, or you have developed a drug tolerance. Drug tolerance occurs when your body gets used to the opioid you’re taking. Many people don’t develop a tolerance to opioids. But if you do develop drug tolerance, usually small increases in the dose or a change in the kind of medicine will help relieve the pain.
Having to increase your dose of opioids to relieve increasing pain or to overcome drug tolerance does not mean that you are addicted.
Not everyone has side effects from opioids. The most common side effects are usually sleepiness, constipation, nausea, and vomiting. Some people might also have dizziness, itching, mental effects (such as nightmares, confusion, and hallucinations), slow or shallow breathing, or trouble urinating.
Many side effects from opioid pain medicine can be prevented. Some of the mild ones such as nausea, itching, or drowsiness, often go away on their own after a few days as your body adjusts to the medicine. If you're having any side effects, let your doctor or nurse know and ask for help managing them.
Here are a few of the more common side effects:
When you first start taking opioids, they might make you sleepy. If pain has kept you from sleeping, you may sleep more for a few days after starting opioids while you “catch up” on your sleep. You also will get less sleepy as your body gets used to the medicine. Call your doctor or nurse if you still feel too sleepy for your normal activities after you’ve been taking the medicine for a week.
Sometimes it may be unsafe for you to drive a car, or even to walk up and down stairs alone. Don’t do anything that requires you to be alert until you know how the medicine affects you.
Here are some ways to handle sleepiness:
Opioids cause constipation in most people, but it can often be prevented or controlled. Opioids slow the movement of stool through the bowels, which allows more time for water to be absorbed by the body. The stool loses water and becomes hard. When you start taking opioids, your doctor might also suggest taking a laxative, stool softener, or other treatment to help keep your stool soft and your bowels moving. See Constipation for more information.
Nausea and vomiting caused by opioids usually goes away after a few days of taking the medicine. See Nausea and vomiting for more information.
Some people think they’re allergic if they have nausea after they take an opioid. Nausea and vomiting alone usually are not allergic reactions. But a rash or itching along with nausea and vomiting might be an allergic reaction. If this happens, stop taking the medicine and call your doctor right away. If you have swelling in your throat, hives (itchy welts on the skin), or trouble breathing, get help right away.
You should not stop taking opioids suddenly. People who need or want to stop taking opioids are usually tapered off the medicine slowly so that their bodies have time to adjust. If you stop taking opioids suddenly and develop a flu-like illness, excessive sweating, diarrhea, or any other unusual reaction, tell your doctor or nurse. These symptoms can be treated and tend to go away in a few days or weeks. Check with your doctor about the best way to taper off your pain medicines and minimize these side effects.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
American Cancer Society. American Cancer Society’s Guide to Controlling Cancer Pain. 2020. Available by calling 800-227-2345.
Brant, JM, Stringer, LH. Pain. In Brown CG, ed. A Guide to Oncology Symptom Management. 2nd ed. Pittsburgh, PA. Oncology Nursing Society; 2015:505-529.
Camp-Sorrell D, Hawkins RA. Clinical Manual for the Oncology Advanced Practice Nurse, 3rd ed. 2014. Pittsburgh: Oncology Nursing Society.
FDA. FDA updates prescribing information for all opioid pain medicines to provide additional guidance on safe use. US Food and Drug Administration. Accessed at www.fda.gov/drugs/drug-safety-and-availability/fda-updates-prescribing-information-all-opioid-pain-medicines-provide-additional-guidance-safe-use
Grossman SA, Nesbit S. Cancer-related Pain. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia: Elsevier, 2019.
Leblanc TW, Kamal AH. Management of Cancer Pain. In DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2019:2190-2390.
National Cancer Institute (NCI). Cancer Pain (PDQ®) – Patient Version. 2022. Accessed at https://www.cancer.gov/about-cancer/treatment/side-effects/pain/pain-pdq
National Comprehensive Cancer Network (NCCN). Adult Cancer Pain. Version 1.2023. Accessed at www.nccn.org on April 3, 2023.
Portenoy, R., Mehta, Z., & Ahmed, E. Cancer pain management with opioids: Optimizing analgesia. In: Abrahm J, ed. UpToDate, 2023. Accessed at www.uptodate.com/contents/cancer-pain-management-with-opioids-optimizing-analgesia.
Shin JA. Pain. In Holland JC et al., ed. Psycho-Oncology : A Quick Reference on the Psychosocial Dimensions of Cancer Symptom Management, edited by Jimmie C. Holland, et al., Oxford University Press, Incorporated, 2015:97-106.
Last Revised: May 23, 2023
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