Cancer Pain Medication Side Effects

Cancer patients often experience pain, whether the pain is caused by the cancer itself or it is caused by treatments. In many cases, opioids are prescribed to help patients manage their pain, and these medications often come with their own uncomfortable side effects. Learn about cancer pain medication side effects and steps you can take to diminish them.


One of the most common side effects of cancer pain medications or opioids is drowsiness. Sometimes the person adjusts to the medication over time, and this can be helpful in reducing drowsiness. In some cases, though, other medications may be prescribed to help patients stay awake during the day.

Dry Mouth

Dry mouth is an annoying side effect that often comes with taking opioids or cancer pain medications. Doctors or dentists can prescribe special mouth rinses to help with dry mouth. It is also helpful for a patient to sip water or suck on hard candies or ice cubes.


Nausea is a very common side effect of pain medications. Doctors may prescribe anti-nausea pills or suppositories to help with this.


Many patients who take opioids to help them cope with pain experience constipation. It is very common for patients to be prescribed stool softeners or laxatives at the same time they are prescribed opioids.


Confusion is especially common when a patient first begins to take a cancer pain medication. To help with confusion, doctors may try other medications for the patient, lower the dose, change the frequency, or prescribe secondary medications to help with confusion.


Many patients who use opioids to deal with cancer pain experience generalized itching, known as pruritis. While this can go away over time, doctors may also prescribe medications that will help lessen this side effect.