More than 50 per cent of patients prescribed opioids get more than they need, and lot of them share the drugs or doesn't store them securely, according to research published online June 13 in JAMA Internal Medicine.

Over 165,000 Americans have been killed from prescription opioid-related overdoses since 1999.

Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues investigated 1,055 adults in 2015 who had been prescribed opioids in the past year. Almost 47 percent were taking opioids at the time of the survey. All were asked about their own opioid use, their opioid storage habits, and whether they shared their medication to others. A total of 1,032 participants finished the survey.

Of patients who shared their medication, approximately 8 percent said they gave them to a friend and 14 percent said they shared with their relative. Almost three-quarters said they gave their extra meds to someone they knew who also battling with pain, the study discovered.

On the other hand, only 10 percent of patients said they stored their opioids under lock while only about 20 percent said they even kept their drugs in a "latched" location.

Dr. Anupam Jena, an associate professor of health care policy and medicine at Harvard Medical School, said opioid abuse happening in many different ways -- legitimate or otherwise.

"There is," he said, "a wealth of evidence that opioids are obtained from physicians in the outpatient setting, sometimes multiple physicians, from friends and family, family members, from the internet, and from illicit sources."

A shortcoming of the study was its use of self-reported data, which can lead to bias.

"More research is needed to identify effective strategies to advance safer practices related to opioid medication sharing, storage and disposal. In the meantime, reducing the prescribing of large quantities of opioid medications and disseminating clear recommendations on safe storage and disposal of opioid medications widely to the public and prescribers may reduce risks," the research noted.