NEW YORK (Reuters Health) - When given in the appropriate doses to treat cancer pain, morphine will not hasten a patient's death by interfering with his or her breathing, a new study shows.

The findings contradict the conventional wisdom-held by many medical professionals as well as lay people--that giving dying patients opioids for pain can shorten their lives by depressing their respiration. "It's in all the textbooks as something to be aware of, but probably the risk has been exaggerated," Dr. Declan Walsh of The Cleveland Clinic Foundation in Ohio, one of the study's authors, told Reuters Health. "It's not that there isn't a risk, but that we've been perhaps been overly concerned about it."

To investigate how morphine affects respiration when given to terminally ill patients, Walsh and his team monitored breathing and vital signs in 29 patients who had been admitted to the hospital for treatment of poorly controlled cancer pain. He and his colleagues had previously investigated respiration in cancer patients after the appropriate dosage of morphine had been reached. In the current study, they looked at respiration as the dosage was being adjusted.

They found no evidence for any respiratory depression in the patients, all of whom maintained blood oxygen saturation levels of 92 percent or greater throughout the study.

The findings show, Walsh said, that "morphine can be used safely even in patients who are very ill to relieve pain, and that physicians need not be as concerned about the use of the drug in that situation as we have been traditionally taught. This is all contingent on morphine being prescribed correctly."

Knowledge of how best to prescribe opioids has progressed considerably over the past two decades, thanks largely to experience with patients rather than controlled studies, he added.

"It's really how the drugs are used rather than any intrinsic problem with the drug that's at issue here," Walsh said. "Good physician training and good training of nursing personnel involved can really make a difference."

In a commentary accompanying the study, Drs. Rob George of University College London and Claud Regnard of St. Oswald's Hospice write: "We urge those in the medical community to understand the facts about morphine and other opioids - it's time to set the record straight. Doctors should feel free to manage pain with doses adjusted to individual patients so that the patients can be comfortable and be able to live with dignity until they die."