Pain (PDQ®): Supportive care - Patient Information [NCI] - Using Drugs to Control Pain
Most patients with cancer pain will need to receive opioids on a regular schedule.
Receiving opioids on a regular schedule helps manage the pain and keeps it from getting worse. The amount of time between doses depends on which opioid is being used. The correct dose is the amount of opioid that controls your pain with the fewest side effects. The dose will be slowly adjusted until there is a good balance between pain relief and side effects. If opioid tolerance does occur, it can be overcome by increasing the dose or changing to another opioid.
Sometimes, the opioid dose needs to be decreased or the opioid is stopped. This may be done when you no longer have pain because of treatments such as nerve blocks or radiation therapy. The doctor may also decrease the dose if it makes you too sleepy or if your kidney function decreases.
Opioids may be given in different ways.
Opioids may be given by the following ways:
Mouth: If your stomach and intestines work normally, medicine is usually given by mouth. Opioids given orally are easy to use and usually low-cost. Oral opioids are sometimes placed under the tongue or on the inside of the cheek to be absorbed.
Rectum: If you cannot take opioids by mouth, they may be given as rectal suppositories.
Skin patches: Opioid patches are placed on the skin.
Nose spray: Opioids may be given in the form of a nasal spray.
Intravenous (IV) line: Opioids are given into a vein only when simpler and less costly methods cannot be used, don't work, or are not wanted by the patient. Patient-controlled analgesia (PCA) pumps are one way to control pain through your IV line. A PCA pump allows the patient to control the amount of drug that is used. With a PCA pump, you can receive a preset opioid dose by pressing a button on a computerized pump that is connected to a small tube. Once the pain is controlled, the doctor may prescribe regular opioid doses based on the amount you used with the PCA pump.
Subcutaneous injection: Opioids are given by injection into the fatty layer of tissue just under the skin. The small needle used for the injection may be left in place for up to one week.
Intraspinal injection: Intraspinal opioids are injected into the fluid around the spinal cord. These may be combined with a local anesthetic to help some patients who have pain that is very hard to control.