Use of narcotic painkillers and anti-anxiety medications among elderly patients is rising sharply, according to an examination of Medicare data by USA Today. The newspaper found older patients are using the medications for longer periods than in the past.

The newspaper estimates that one in five of the nation’s 43 million senior citizens receive Medicare prescriptions for opioid painkillers, many of them for long periods.

The number of patients 65 and older who received Medicare prescriptions for opioids increased more than 30 percent between 2007 and 2012, the newspaper found. An estimated 8.5 million elderly patients received opioid prescriptions in 2012. Use of some of the most commonly abused opioids, including oxycodone and hydrocodone, increased more than 50 percent. The amount of each opioid given to patients increased an average of 15 percent, to about three months worth of medication.

Prescriptions for anti-anxiety medication rose about 25 percent between 2007 and 2012, to more than 700,000. The average patient received the drugs for five months—about 10 percent more than 2007.

According to Michael Von Korff of the Group Health Research Institute in Seattle, elderly patients who take opioids or anti-anxiety medications are at increased risk of injuries from falls, cognitive problems and impaired breathing. He noted the risks are increased when the drugs are used in combination. “Misuse and abuse of these medicines is not uncommon among the elderly. They do get into trouble with these drugs,” he said.

Last month, USA Today reported in 2013, 55 million opioid prescriptions were written for people 65 and older, marking a 20 percent increase over five years—almost double the growth rate of the elderly population. During the same period, the number of benzodiazepine prescriptions rose 12 percent, to 28.4 million.