Pain Control Support for People With Cancer by National Institute of Cancer. - HTML preview

Managing and preventing side effects

Some pain medicines may cause:

• Constipation (trouble passing stools)
• Drowsiness (feeling sleepy)
• Nausea (upset stomach)
• Vomiting (throwing up)

Side effects vary with each person. It’s important to talk to your doctor often about any side effects you’re having. If needed, he or she can change your medicines or the doses you’re taking. They can also add other medicines to your pain control plan to help your side effects.

Keep in mind that constipation will only go away if it’s treated. But don’t let any side effects stop you from getting your pain controlled. Your health care team can talk with you about other ways to relieve them. There are solutions to getting your pain under control.

Other less common side effects include:

• Dizziness
• Confusion
• Breathing problems
• Itching
• Trouble urinating

Constipation

Almost everyone taking opioids has some constipation. This happens because opioids cause the stool to move more slowly through your system, so your body takes more time to absorb water from the stool. The stool then becomes hard.

You can control or prevent constipation by taking these steps:

• Ask your doctor about giving you laxatives and stool softeners when you first start taking opioids. Taking these right when you start taking pain medicine may prevent the problem.
• Drink plenty of liquids. Drinking 8 to 10 glasses of liquid each day will help keep stools soft.
• Eat foods high in fiber, including raw fruits with the skin left on, vegetables, and whole grain breads and cereals.
• Exercise as much as you are able. Any movement, such as light walking, will help.
• Call your doctor if you have not had a bowel movement in 2 days or more.

Drowsiness

Some opioids cause drowsiness. Or, if your pain has kept you from sleeping, you may sleep more at first when you begin taking opioids. The drowsiness could go away after a few days.

If you’re are tired or drowsy:

• Don’t walk up and down stairs alone.
• Don’t do anything where you need to be alert—driving, using machines or equipment, or anything else that requires focus.

Call your doctor if the drowsiness is severe or doesn’t go away after a few days.

• You may have to take a smaller dose more often or change medicines.
• It may be that the medicine isn’t relieving your pain, and the pain is keeping you awake at night.
• Your other medicines may be causing the drowsiness.
• Your doctor may decide to add a new drug that will help you stay awake.

Nausea and vomiting

Nausea and vomiting could go away after a few days of taking opioids. However, if your nausea or vomiting prevents you from taking your medicine, call your doctor right away. You should also call if any breathing problems develop.

These tips may help:

• Stay in bed for an hour or so after taking your medicine if you feel sick when walking around. This kind of nausea is like feeling seasick. Some over-thecounter drugs may help, too. But be sure to check with your doctor before taking any other medicines.
• Your doctor may want to change or add medicines, or prescribe antinausea drugs.
• Ask your doctor if something else could be making you feel sick. It might be related to your cancer or another medicine you’re taking. Constipation can also add to nausea.