A new U.S. study published in JAMA Internal Medicine suggests that Opioid overdoses may be much more likely to happen in families when somebody in the household has been prescribed these drugs.

Even when a family member gets lower doses of opioids – less than 50 morphine milligram equivalents per day – the overdose risk is almost three times higher than it would be in a family where nobody has been prescribed opioids, the study found.

The overdose risk was nearly 8 times greater when a family member was prescribed 50 to 90 morphine milligram equivalents a day; it was more than 15 times higher at doses above 90 morphine milligram equivalents per day.

The new study shows these prescriptions are important risk factors for overdose for others in the household, he said, and overdose reduction and treatment strategies are needed for family members, too.

The team’s findings are drawn from insurance claims data collected from 2004 to 2015 on 2,303 individuals who had an overdose and 9,212 who did not. This study wasn’t designed to prove whether or how opioid prescriptions within families might directly cause overdoses or deaths.

The results underscore the need for precautions when opioids are prescribed.

To reduce overdoses and deaths, many states have implemented programs to restrict and track opioid prescriptions, and some have also enacted or considered caps on the maximum daily doses that can be prescribed.

Still, when one person in a family gets prescribed opioids, the odds go up that another person in the same family will also take these drugs, the study team notes. And having more opioids in the house can make misuse and overdose more likely – especially when people hang on to any unused pills.