Opioid Pain Medicines for Cancer Pain

Opioids (narcotics) are used with or without non-opioids to treat moderate to severe pain. These medicines are much like natural substances (called endorphins) made by the body to control pain. They were once made from the opium poppy, but today many are man-made in a lab.

It’s important to know that you will always need a signed, written prescription (not faxed, emailed, or called in) for opioid pain medicines.

Common opioids by generic name

Here are some of the opioids used in cancer care. Some of the more common brand names are in parentheses.

  • Codeine
  • Hydromorphone (Dilaudid)
  • Levorphanol (Levo-Dromoran)
  • Methadone (Dolophine, Methadose)
  • Morphine (Apokyn, Avinza, Kadian, MS-Contin, and others)
  • Oxycodone (OxyContin, OxyIR, Roxicodone)
  • Hydrocodone
  • Oxymorphone (Opana)
  • Fentanyl (Actiq, Duragesic, Fentora, Lazanda, Subsys, and others)

An “ER” behind the name of any opioid drug names stands for “extended release,” and is a sign that the drug is taken on a regular schedule to treat chronic pain. An “IR” stands for “immediate release” and means that the drug will work quickly and for only a short time. These rapid-onset opioids are used to treat breakthrough pain. Examples of these types of drugs are fast-acting oral morphine; fentanyl in a lozenge, “sucker,” or under-the-tongue spray. (These forms of fentanyl are absorbed from your mouth – they are not swallowed.)

A short-acting opioid, which relieves breakthrough pain quickly, is often used with a long-acting opioid.

    Many times the same opioid drug is used to treat both the chronic and the breakthrough pain, so be sure you know what you’re taking. For example, hydrocodone ER (Zohydro ER) may be for your chronic pain and hydrocodone/ with acetaminophen(Lortab) is for your breakthrough pain. Do not mix them up!

Common opioid and acetaminophen or NSAID drug combinations

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.


Codeine may be added to aspirin or acetaminophen. For instance:

  • Fiorinal with codeine has aspirin
  • Fioricet with codeine has acetaminophen
  • Tylenol #3 and Tylenol #4 contain codeine and acetaminophen


Oxycodone may be added to aspirin, acetaminophen, or ibuprofen. For instance:

  • Percodan has aspirin in it
  • Percocet, Roxicet, Roxilox, Oxycet, and Tylox all have acetaminophen
  • Combunox has ibuprofen


Hydrocodone may be added to acetaminophen or ibuprofen. For instance:

  • Zydone, Norco, and Lortab all contain acetaminophen
  • Vicoprofen and Reprexain have ibuprofen

    If you’re taking a combination pain medicine, be sure you know what drugs are in each pill.

How to get proper pain relief with opioids

When a medicine doesn’t give you the pain relief you need, your doctor may prescribe a higher dose or tell you to take it more often. When your cancer care team is working closely with you, doses of strong opioids can be raised safely to ease severe pain. Don’t decide to take more pain medicine on your own. If changing the dose doesn’t work, your doctor may prescribe a different drug or add a new drug to the one you’re taking.

If your pain relief isn’t lasting long enough, ask your doctor about extended-release medicines that come in pills and patches. These can control your pain for a longer period of time.

If your pain is controlled most of the time, but you sometimes have breakthrough pain, your doctor may prescribe a fast-acting medicine or immediate-release opioid that will give you faster pain relief right when it’s needed.

Taking opioids safely

Doctors will watch you carefully and adjust the doses of pain medicine so you don’t take too much. For this reason, it’s important that only one doctor prescribe your pain medicines. If you have 2 or more doctors, be sure that one does not prescribe opioids for you without talking to the others about it.

If you drink alcohol or take tranquilizers, sleeping pills, antidepressants, antihistamines, or any other medicines that make you sleepy, tell your doctor how much and how often you do this. Taking opioids while drinking alcohol or taking tranquilizers can be dangerous. Even small doses may cause problems. Using such combinations can lead to overdoses and symptoms like weakness, trouble breathing, confusion, anxiety, or more severe drowsiness or dizziness.

Opioid tolerance

You might find that over time you need larger doses of pain medicine. 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, and it takes more medicine to relieve the pain as well as it once did. Many people do not 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.

Managing side effects of opioids

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 without treatment after a few days, as your body adjusts to the medicine. Let your doctor or nurse know if you’re having any side effects and ask for help managing them.

Here are a few of the more common side effects:

Drowsiness or sleepiness

When you first start taking them, opioids might make you sleepy, but this usually goes away after a few days. If your 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:

  • Wait a few days and see if it goes away.
  • Check to see if other medicines you’re taking can also cause sleepiness.
  • Ask the doctor if you can take a smaller dose more often or an extended-release opioid.
  • Ask your doctor what you can do to get better pain relief, if the opioid is not relieving the pain. The pain itself may be tiring you out. In this case, better pain relief may lead to less sleepiness.
  • Ask for a small decrease in the opioid dose. It will still relieve your pain but won’t cause drowsiness. If the drowsiness is very bad, you may be taking more medicine than you need. Talk to your doctor about lowering the amount you’re taking.
  • Ask your doctor about changing to a different medicine.
  • Ask your doctor if you can take a mild stimulant such as caffeine during the day.
  • If drowsiness is bad or if it suddenly starts to be a problem after you’ve been taking opioids for a while, call your doctor or nurse right away.


Opioids cause constipation in most people, but it can often be prevented or controlled. Opioids slow the movement of stool through the intestinal tract, which allows more time for water to be absorbed by the body. The stool then becomes hard. When you start taking opioids, it’s best to take a laxative, stool softener, or other treatment to help keep your stool soft and your bowels moving.

After checking with your cancer care team, try the following to prevent constipation:

  • Talk with your doctor about taking stool softeners and laxatives. Ask how often and how much you should take.
  • Drink plenty of liquids. Eight to 10 8-ounce glasses of fluid each day can help keep your stools soft. This is a very important – if your stool is dry, it will be hard to pass.
  • Eat foods high in fiber or roughage such as uncooked fruits (with the skin on), vegetables, and 100% whole-grain breads and cereals.
  • Add 1 or 2 tablespoons of unprocessed bran to your food. This adds bulk and promotes bowel movements. Keep a shaker of bran handy at mealtimes to make it easy to sprinkle on foods. Be sure to drink plenty of water when you eat bran so that it softens in the bowel.
  • Exercise as much as you can. Talk with your doctor about what kind of exercise is best for you. Walking is often a good start if you haven’t exercised recently.
  • Eat foods that have helped you relieve constipation before.
  • If you haven’t been getting out of bed, try to use the toilet or bedside commode when you have a bowel movement, even if that’s the only time you get out of bed.

If you’re still constipated after trying all the above, ask your doctor about changing your stool softener or laxative. Check with your doctor or nurse before taking any laxative or stool softener on your own. If you haven’t had a bowel movement for 2 days or more, call your doctor.

Nausea and vomiting

Nausea and vomiting caused by opioids will usually go away after a few days of taking the medicine. These tips may help:

  • If you have more nausea when you’re up or walking around but not when you’re lying down, stay in bed for an hour or so after you take your pain medicine. This type of nausea is like motion sickness. Sometimes over-the-counter medicines such as meclizine (Bonine or Antivert) or dimenhydrinate (Dramamine) help this type of nausea. Check with your doctor or nurse before taking these medicines, since they can cause problems for some people.
  • If pain itself is causing the nausea, relieving the pain usually makes the nausea go away.
  • Medicines that relieve nausea can be prescribed if you need them. Talk with your doctor or nurse if you can’t hold down foods or liquids for a full day, or if nausea lasts more than a few days.
  • Ask your doctor or nurse if the cancer, another medical problem, steroids, chemo, or other medicines might be causing your nausea. Constipation may also worsen nausea.

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 may 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.

When you no longer need opioids

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 to it. 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 to a few weeks. Again, slowly decreasing your opioid dose over time usually keeps these kinds of symptoms from happening. Check with your doctor about the best way to taper off your pain medicines.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: September 24, 2015 Last Revised: May 12, 2016

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