These medications, available over-the-counter as well as by prescription, do their work by reducing swelling and inflammation. Some NSAIDs, notably ibuprofen, aspirin and naproxen, have a greater impact on inflammation than does acetaminophen. As mentioned above, sometimes NSAIDs are combined with opioids to fight pain.

Side Effects. Some NSAID medications can cause gastrointestinal problems, especially ibuprofen and aspirin. Acetaminophen does not cause this side effect, and the newest NSAIDs, the COX-2 inhibitors Celebrex and Vioxx, reportedly have a minimal impact on the gastrointestinal tract. However, it's important to know that the COX-2 inhibitors have not been tested for cancer pain relief, and are presently used only to treat arthritis pain. Acetaminophen should not be taken by people who have three or more alcoholic drinks in the course of 24 hours, as damage to the liver can result.

If you are taking cancer pain medications that contain NSAIDs, don't take additional over-the-counter pain medications without discussing this with your physician or nurse.

These medications are most often used to treat moderate to severe cancer pain, and they are always prescription medications. Opioids are sometimes combined with acetaminopen (Percocet) or aspirin (Percodan), for example. These medications can be taken in a wide variety of ways orally, by patch, rectally, by injection, transmucosally and are formulated to be long- and short-acting. Almost always, opioid treatment for cancer pain begins with a low dose, and the dosage is increased until pain relief is satisfactory to the person in pain.

For many people experiencing cancer pain that is expected to continue, opioids should be administered on an around-the-clock basis, rather than given only when pain becomes intense. The around-the-clock approach provides a consistent level of the medication in the blood, and this helps to provide a fairly consistent level of pain relief, preventing abrupt peaks and valleys of pain. Additionally opioid formulations for breakthrough pain probably should be provided.

Side Effects. Opioid medications can produce a variety of side effects. The most important to know about are:

Constipation. Almost without exception, every person using opioid medications on a regular basis experiences constipation, unless he or she is given information about a special bowel regimen designed to head off this problem, which can be very painful. Many cancer pain experts recommend that a bowel regimen be started immediately when opioid medications are prescribed. People taking these medications should also drink 8- 10 glasses of water each day, and increase fiber in their diet, if possible.

Nausea and vomiting. Some people experience nausea and sometimes vomiting when they begin using opioids. There are excellent anti-emetic (anti-nausea) prescriptions medications available today, such as Zofran and Kytirl; ask your health care provider about using them to combat nausea. For most people, the nausea fades away after taking the medication for a short period of time.

Sleepiness. It is not unusual for some people beginning opioids to experience sleepiness for several days. For most people, this is a temporary side effect, and it is worthwhile to stay on the medications for a few days to see if the drowsiness fades away. If the sleepiness is severe, contact your health care provider.

Respiratory depression. A serious side effect of opioids is slow, shallow breathing. This side effect rarely occurs when opioids are taken as prescribed.  If you have concerns about this side effect, be sure to discuss them with your health care provider.