Why it's good and bad that people don't take all their painkillers after surgery

Surgery patients often have leftover opioids prescribed for pain, a new review suggests. Doctors in the U.S. say the findings reflect how little is known about how much pain medication people really need.

The leftover pills have an immediate advantage in that patients are cautious about overtreating their postoperative pain.

But there are also disadvantages:

• Unused pills may be diverted for nonmedical misuse, which doctors and researchers say likely contributes to opioid-related deaths and injuries.
• It shows how poorly physicians understand pain and how to manage it. 

Recognizing this, Dr. Mark Bicket, an anesthesiologist and pain specialist at Johns Hopkins University School of Medicine in Baltimore and his team reviewed six earlier studies on about 800 patients to see how commonly prescription opioids remain unused among adults after surgery. The operations included orthopedic, obstetric and dental procedures.

They found 67 per cent to 92 per cent of patients in the U.S. who were prescribed opioids following surgery reported winding up with leftover pills, Bicket and colleagues report in Wednesday's issue of JAMA Surgery.

"This is a kind of call to action partly to inform surgeons of a problem we need to address," Bicket said in an interview with Reuters.  

"We need better ways to identify the needs for pain medication for patients after surgery, and right now we don't have the tools."

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In the studies that looked at why patients didn't consume the medications, most (71 per cent to 83 per cent) said their pain had subsided. Fewer (16 per cent 29 per cent) said they were concerned about addiction and side-effects such as nausea, vomiting or constipation.

Rates of safe storage and disposal of unused prescription pills were low. About one in four patients reported storing opioids in a locked cabinet out of reach of children or teens.

The Canadian Centre on Substance Abuse and its partners encourage people to return unused and expired prescription drugs at pharmacies and police stations on National Prescription Drug Drop-off Day. Local pharmacies may also accept medications year round and police departments have drop-off days.

One obstacle to curbing prescribing is surgeons don't have guidelines on how much pain medication to dispense to patients when they leave the hospital, and there is no data or research to draw on for direction, Bicket said.

He suggested that doctors spend more time assessing a patient's postoperative pain and personalize the dose accordingly. Non-opioid options, such as acetaminophen and naproxen, can suffice for moderate postoperative pain, previous studies suggest.  

To shed more light, Debra Gordon, co-director of the Harborview Integrated Pain Care Program at the University of Washington in Seattle, called for the creation of registries to collect information on individual surgical patients and how well their pain is managed. 

Gordon, a clinical nurse specialist who was not involved in the new research, said the way that the health-care system is set up facilitates the problem. Doctors don't want to be called days after a patient goes home to write another prescription for painkillers. 

In the research reviewed, between zero to 21 per cent of patients said they did not fill their opioid prescription. Between 7 to 14 per cent filled the prescription but did not take any pills.

The researchers said studies varied in quality. Another limitation is that data on usage and disposal were based on self-reports by patients.