Chronic pain: Do opioid painkillers really help?

Currently there are more than 100 million American suffering from chronic pain. As much as 5 to 8 million patients use narcotics to manage their condition even though these drugs may not be the most effective treatment, according to a new study published in the journal Annals of Internal Medicine.

In the medical field, chronic pain is defined as pain and discomfort that lasts for longer than three months, does not improve in the time period it's expected to and limits a person's activities and quality of life. "When you break your arm, that's what we call acute pain. When the bone heals and the pain continues, that's when it's called chronic pain," medical contributor Dr. David Agus told "CBS This Morning."

"It's caused from anything from an accident to back pain to a headache to a particular disease you have," he said.

There are also a number of chronic conditions unrelated to injuries that doctors may treat with narcotic painkillers, including lower back pain, arthritis, headaches, multiple sclerosis, fibromyalgia, shingles and nerve damage.

But while pain that is related to these conditions is serious and debilitating, the study shows that often narcotics are ineffective for treatment.

There currently are no set guidelines that indicate what dosage of drugs such as Vicodin, Oxycontin and Percocet a patient with certain conditions should receive. This means may people looking to manage chronic pain may often end up taking too much -- or too little -- of these drugs, even under a physician's guidance.

"Doctors are [prescribing] without a lot of training," said Argus. "And narcotics, as we know, have a lot of side effects."

These drugs are the cause of many hospital visits due to addiction, which continues to be on the rise. In 1991 there were a total of 76 million hospital admissions from narcotics; that number increased to 219 million in 2011. These drugs also take a significant financial toll on the U.S. health care system, costing as much as $635 billion a year.

"While they can help pain in the short run, there aren't real studies showing they work past three or six months. The studies just haven't been done, so we're kind of flying blind in the medical world," said Agus. "We've got to pool resources for research, do the right long-term studies and figure out a new way here because we are all suffering."