Side Effects of Opioids
Patients should be watched closely for side effects of opioids. The most common side effects of opioids include nausea, sleepiness, and constipation. The doctor should discuss the side effects with patients before starting opioid treatment. Sleepiness and nausea are usually experienced when opioid treatment is started and tend to improve within a few days. Other side effects of opioid treatment include vomiting, difficulty in thinking clearly, problems with breathing, gradual overdose, and problems with sexual function. Chronic nausea and vomiting in patients receiving long-term opioid treatment may be caused by constipation.
Opioids slow down the muscle contractions and movement in the stomach and intestines resulting in hard stools. The key to effective prevention of constipation is to be sure the patient receives plenty of fluids to keep the stool soft. Unless there are problems such as a blocked bowel or diarrhea, patients will usually be given a regimen to follow to prevent constipation and information on how to manage bowel health while taking opioids.
Patients should talk to their doctor about side effects that become too bothersome or severe. Because there are differences between individual patients in the degree to which opioids may cause side effects, severe or continuing problems should be reported to the doctor. The doctor may decrease the dose of the opioid, switch to a different opioid, or switch the way the opioid is given (for example intravenous or injection rather than by mouth) to attempt to decrease the side effects. (Refer to the PDQ summaries on Gastrointestinal Complications, Nausea and Vomiting, Nutrition in Cancer Care, and Sexuality and Reproductive Issues for more information about coping with these side effects.)
Drugs Used with Pain Medications
Other drugs may be given at the same time as the pain medication. This is done to increase the effectiveness of the pain medication, treat symptoms, and relieve specific types of pain. These drugs include antidepressants, anticonvulsants, local anesthetics, corticosteroids, bisphosphonates, and stimulants. The use of cannabinoids added to pain medicine is being studied for cancer-related pain. A monoclonal antibody called denosumab is used to prevent broken bones and other bone problems caused by solid tumors that have metastasized (spread) to bone. There are great differences in how patients respond to these drugs. Side effects are common and should be reported to the doctor.