PITTSBURGH -- Most patients going home with opioid painkillers after orthopedic surgery at Johns Hopkins University didn't use all the pills they were given, suggesting that these medications are routinely overprescribed, a researcher said here.

Among 93 patients interviewed during the succeeding 4 weeks after discharge, 85% of those who had stopped taking the drugs still had them in the cabinet, said Mark Bicket, MD, of Hopkins' division of pain medicine in Baltimore.

And many of the patients had large numbers of tablets remaining: 28% had 20 or more pills still in their possession, and 24% retained doses at least 200 morphine-equivalent.

Bicket presented the findings at the American Pain Society's annual meeting here.

Nearly 20% of the patients were no longer taking the opioids when interviewed on the 2nd day after discharge; a little less than half had stopped at the 2-week mark.

About 10% of the patients had 80 or more unused pills after stopping, Bicket said.

The upshot, he said, is that more research is needed on determining how much painkiller medication patients are really likely to need after orthopedic surgery -- and the results need to be conveyed to surgeons, who do most of the prescribing.

He said surgeons currently have little to go on, and so they tend to be liberal in prescribing in order to minimize complaints about inadequate pain control during recovery.

For the study, Bicket and colleagues recruited orthopedic surgery patients to agree to complete serial surveys during their hospital stay and several times during the 4 weeks post-discharge; 101 agreed initially but eight did not complete all the surveys.

Patients had a mix of procedures: 43% had back surgery, 25% had shoulder operations, 18% of procedures involved the hip or knee, and the remainder involved other body parts. Some 60% were performed as inpatient procedures.

A total of 121 prescriptions were written, most involving oxycodone in various formulations. Thirteen were for hydromorphone, seven were for tramadol, and a handful were for other opioids such as morphine or transdermal fentanyl.

Most patients said they were satisfied with their pain control; less than 5% called it poor.

Few, however, said they knew how to store or dispose of unused opioid pills responsibly, and even fewer said they had actually done so.

Those findings were echoed in a separate report presented at the APS meeting by researchers from the University of Washington in Seattle.

According to Christine Bockman, PharmD, and colleagues, who also surveyed orthopedic surgery patients after discharge (n=41), only 22% said they had been told how to dispose of unused opioids.

When interviewed 2 weeks after surgery, 17% told the researchers they had been given too many pills. (On the other hand, nearly as many said they were given too few, and 27% had already requested a refill.)

And also in line with the Hopkins study, Bockman and colleagues found that 41% had kept some pills after stopping.