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Managing Cancer Care

How Pain Medicines Are Given

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Some people think that if their pain becomes severe, they’ll need injections or “shots” of pain medicine. Shots may be needed depending on the type of medicine given, but there are many other ways you can take pain medicine.

Oral: The medicine is taken by mouth, either by being swallowed or dissolved and absorbed on the tongue or inside the cheek. Oral pain medicine is given as a liquid, pill, capsule, or transmucosal form in a lozenge, “sucker,” or spray absorbed directly through the tissues of the mouth.

Never crush, break, or open extended-release pills or capsules. Talk to your doctor if you have trouble swallowing your pain medicines. There are many different ways to take them.

Skin patch: A clear, sticky patch placed on the skin. It slowly – but constantly – releases medicine through the skin for 2 to 3 days.

Rectal suppositories: Medicine that is inserted into in the rectum, dissolves, and then is absorbed by the body.

Injections: There are several ways medicines can be injected.

  • Subcutaneous (SC) injection – medicine is put just under the skin using a short, small needle.
  • Intramuscular (IM) injection - medicine is put deeper into a muscle (usually in the arm, leg, or buttocks) using a medium length needle. This method is rarely used for pain medicines if other options are available.
  • Intravenous (IV) injection – medicine goes right into a vein through a needle, port, or catheter.
  • Intrathecal and epidural injections – medicine is put into the fluid around the spinal cord (intrathecal) or into the space around the spinal cord (epidural).

Pump, or patient-controlled analgesia (PCA): The pump is connected to a small tube going into your body. The medicine in the pump goes into a vein, just under the skin, or into the area around the spine.

 When you need pain relief, you press a button to get a pre-set dose of pain medicine through a computerized pump. (The pump carefully controls how much you can get at a time, so you can’t take too much.) With this method, you have control over the amount of pain medicine you take.

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. 2018. 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.

National Cancer Institute (NCI). Cancer Pain (PDQ®) – Patient Version. 2018. Accessed at

National Comprehensive Cancer Network (NCCN). Adult Cancer Pain. Version 1.2018. Accessed at on December 17, 2018.

Last Revised: January 3, 2019