My mother fell last winter on the ice and ended up with a nerve injury in her right shoulder. Despite all treatment so far, nothing has worked. Now she's become a chronic pain patient. I notice the doctor keeps changing her drugs. The dose goes up, then she's switched to another drug. Then she's taking two or three drugs. Does this seem right?

Controlling chronic pain with medications is a complex and challenging job. This is especially true if the doctor is using opioids as part of the treatment. Opioids are narcotics such as morphine (MS Contin or OxyContin) or fentanyl (Duragesic). You may recognize one of these names from your mother's bottles of pills.

Opioids reduce pain by binding to opioid receptors in the brain. Most pain responds well to opioid medications. Some types of pain respond better than others. For example, nociceptive (skeletal or muscular pain) is usually more responsive than neuropathic (nerve) pain.

Patients often get good relief from opioids at first. But they develop tolerance to the drug and may need a higher dose to get the same amount of pain relief. Many people can't really tolerate taking a higher dose. One way to handle this is to start at a low dose and gradually increase the amount taken as needed. When the maximum safe dose is reached, the doctor may switch the patient to a different drug.

Or sometimes combining a narcotic with an antidepressant and/or a regular analgesic works well. This is called multimodal drug therapy. Multimodal therapy and drug rotation may be the best way to treat chronic nerve pain.

If you have any doubts or questions, go with your mother to her next appointment. Educating the patient and the family is an important part of pain control. Find out what she's on and how it works. Ask what to expect for short-term and long-term pain control.