For the first time, research has compared the safety of some of the most commonly used painkillers. And the drugs that raised the biggest questions? Opioids -- the regularly prescribed class of painkillers that include Vicodin and OxyContin.
In two new reports published in the Archives of Internal Medicine, researchers from Brigham and Women's Hospital in Boston found that opioid users experienced higher rates of serious problems than patients taking other types of painkillers, such as coxibs or nonsteroidal anti-inflammatory drugs, or NSAIDs.
"In the past decade, people have increased their opioid use, and I think that's partly based on the fact that other drugs were [found to be] dangerous, but no one has done an analysis of opioids," said Dr. Daniel Solomon, an associate professor of medicine at Harvard Medical School and lead author of the study. "But now opioids aren't looking so good either."
The use of hydrocodone, brand name Vicodin, and oxycodone, brand name OxyContin, nearly doubled between 2001 to 2006. Doctors said a major reason for the spike came from noncancer patients taking the painkiller.
One in five American adults received a painkiller prescription in 2006, which translates to more than 230 million total prescription purchases.
And last year, the Centers for Disease Control and Prevention reported that the number of fatal opioid poisonings more than tripled from 4,000 to 13,800 deaths between 1999 and 2006.
Before this study, almost no information existed on the comparative safety of opioids.
"Not that our study is the final word, but it can be a means to start a discussion of benefits and risks of some of the most commonly used drugs," said Solomon.
In the first report, researchers collected Medicare data between the years 1996 and 2005. The data included information from more than 31,000 older Americans who had been prescribed an NSAID, coxib or opioid.
Opioid users experienced higher rates of cardiovascular problems and fractures than patients taking other types of painkillers.
In the second report, the authors compared the rates of serious problems occurring after 30 and 180 days among patients taking one of five opioids: codeine, hydrocodone, oxycodone, propoxyphene and tramadol. They found that patients taking codeine or oxycodone were about twice as likely to die from any cause compared with patients taking hydrocodone (Vicodin), an opioid similar to oxycodone and stronger than codeine.
"I am not surprised that oxycodone carries a higher risk of death than hydrocodone," said Dr. Doris Cope, director of University of Pittsburgh's Pain Medicine Program. "From a clinical perspective, oxycodone rather than hydrocodone is more often prescribed for patients [with] more extensive pathology and pain who are thus more likely to sustain life-threatening illnesses."
In addition, patients taking codeine for at least three months were found to have a 62 percent increased risk of cardiovascular problems compared with those taking hydrocodone.
"I will actively discourage codeine usage in my patients at risk for cardiovascular disease," continued Cope. "It is an older analgesic, which is less effective than other medications but as equally addictive when compared with stronger pain relievers."
Dr. Timothy Collins, assistant professor of medicine and neurology at Duke University Medical Center, said that the results could change clinical practice.
"The biggest impact for the average physician should be increased awareness of the problems with opioids in older adults," said Collins. "We have previously thought there were no risks other than sedation, which does increase the risk of falls."
Still, experts noted that the reports have their limitations. The study's design did not permit researchers to compare patients based on pain diagnosis, pain severity or known use of over-the counter medications.
In recent years, the FDA has issued warnings on the dangers of opioids because of their addictive nature and the questionable safety of their long-term and short-term use. Last February, the FDA issued a proposal that tried to limit the growing misuse of opioid drugs.
In November, the FDA requested that propoxyphene's maker, Xanodyne, remove the drug from shelves after clinical data found that the drug put patients at serious risk for heart arrhythmias.
So what are patients in pain to do?
Cope said it's important to note that patients taking painkillers need to be carefully educated on the risks and benefits of these medications. She says they also need individualized evaluation and treatment.
"It would be a backward step in medical care if pain medicines were limited and prescribed based on mean group data rather than assessing each patient as an individual based on his or her pathology, function, pain status and a wide array of options," said Cope.
That being said, Dr. Gunnar Andersson, professor and chairman of the department of orthopedic surgery at Rush University Medical Center in Chicago, said doctors and patients must be careful not to overinterpret these results.
"In the right patient, these drugs are invaluable," said Andersson. "We just need to remind ourselves that musculoskeletal pain and headaches rarely require narcotics, particularly not for extended periods of time."
Despite the value of narcotics for some patients, Andersson said he worries about the preoccupation with pain these days. As the fifth vital sign, doctors must regularly document their patients' pain levels, and no patient is supposed to have any pain and go without treatment.
"This encourages oversubscription and overuse, and there is no evidence that the individual with noncancer pain actually gets more benefit than complications," continued Andersson. "We need a debate, which I hope these manuscripts will stimulate."