MONDAY, Dec. 13 (HealthDay News) -- Two new studies suggest that Medicare patients who take opioid painkillers such as codeine, Vicodin or Oxycontin face higher health risks, including death, heart problems or fractures, compared to those taking non-opioid analgesics.

However, it's not clear if the painkillers are directly responsible for the differences in risk, experts said, and other factors could play a role. And one pain specialist who's familiar with the findings said they don't reflect the experiences of doctors who've prescribed the drugs.

In one study, researchers examined a database of Medicare recipients in two states who were prescribed one of five kinds of opiod painkillers from 1996-2005. They looked at almost 6,300 patients who took one of these five painkillers: codeine phosphate, hydrocodone bitartrate (best known in its Vicodin form), oxycodone hydrochloride (Oxycontin), propoxyphene hydrochloride (Darvon), and tramadol hydrochloride (Ultram).

Those who took codeine were 1.6 times more likely to have suffered from cardiovascular problems after 180 days, while patients on hydrocodone seemed to be at higher risk of fractures than those who took tramadol and propoxyphene.

After 30 days, those who took oxycodone were 2.4 times more likely to die than those taking hydrocodone, and codeine users were twice as likely to die, although the number of deaths was small.

The study authors caution that their findings are surprising in some ways and need to be confirmed by further research.

Commenting on the study, Dr. Russell K. Portenoy, chairman of the department of pain medicine and palliative care at Beth Israel Medical Center in New York City, said that the findings are of limited value because many other factors could explain the differences between the drugs, such as how fast physicians ramped up the doses of patients.

"I would suggest that readers note this as an observation and wait for the next set of studies to try to figure out if there's any reality in there in terms of risk," he said.

A second study published in the same issue of the journal compared opioid painkillers against non-opioid analgesics, and found that patient "adverse events" were more likely when an opioid was taken.

A team led by Dr. Damiel H. Solomon of Brigham and Women's Hospital, Boston, compared the safety of opioids against non-steroidal anti-inflammatory drugs (NSAIDs, which include aspirin, ibuprofen and naproxen) and "coxib" drugs such as Celebrex (celecoxib). They tracked outcomes for almost 13,000 Medicare recipients who took such pain relievers between 1999 and 2005.

The Boston team found that patients on opioids had higher rates of adverse events generally than did people taking an NSAID or a coxib drug. For example, 101 of every 1,000 prescription opioid users suffered a fracture in a given year versus 19 of every 1,000 people taking another type of painkiller. Coxibs and opioids were also associated with a higher risk for cardiac events compared to NSAID use, the team found.

What to do if you're taking an opioid? "There's no question that opioid drugs carry important risks," Portenoy said. "If you have chronic pain, your doctor should optimize the dosing and be managing the risk: not only the risk of side effects and toxicities but also the risk of things like drug abuse."

More information

There's more on painkillers at the U.S. National Library of Medicine.