Morphine found to help stave off PTSD in wounded troops
More than 200 years after it was isolated from poppies, morphine remains one of medicine's best painkillers. But that isn't its only use.
Physicians sometimes include the drug in a cocktail of medications given to people having heart attacks. It can relieve the breathlessness of pulmonary edema. It decreases diarrhea. A famous physician of the early 20th century, William Osler, once called morphine "God's own medicine."
Research published this week suggests that the compound might have at least one more use.
In a study of about 700 troops who were wounded in Iraq, those who received morphine soon after being injured were about half as likely to develop post-traumatic stress disorder as those who did not get the drug.
It is not known whether morphine's apparently protective effect arises directly from the relief of traumatic pain or indirectly by blocking the brain circuits that lay down traumatic memory.
The researchers and outside experts agreed that the effect would have to be proved virtually beyond a doubt before morphine would be routinely given to prevent the mental disorder.
"I would be very reluctant to suggest any change in clinical practice," said Troy Lisa Holbrook of the Naval Health Research Center in San Diego, who headed the study published in the New England Journal of Medicine. "We need to understand a great deal more how this appears to work."
Morphine has been used for pain relief from battle wounds as far back as the Civil War. Since World War II, medics and hospital corpsmen have carried small injectors filled with the drug.
Although it is the battlefield painkiller of choice, how commonly it is used in front-line first aid is not known. A recent survey of 114 burn patients treated at the Army Institute of Surgical Research in Texas found that 30 percent had received pre-hospital injections, according to Laura L. McGhee, a researcher there.
PTSD is characterized by intrusive thoughts and memories, a desire to avoid specific situations or stimuli, and feelings of both numbness and extreme vigilance. The disorder is common in veterans of the Iraq and Afghan wars, although its exact prevalence is also uncertain.
About 40 percent of those veterans cared for at Department of Veterans Affairs hospitals have PTSD. Repeat deployment to a war zone increases the risk of developing the disorder. PTSD can also come on slowly. In one study, 4 percent of troops had the condition; six months later, the prevalence was 12 percent.
In the new study, Holbrook and her colleagues looked at the records of 696 wounded forces. About 40 percent had been injured by improvised explosive devices, generally roadside bombs; about 20 percent by gunshots and 10 percent by mortar rounds. About 70 percent received morphine within an hour of being hurt.