Prescription drug overdoses on the rise in U.S.

A pharmacy employee dumps pills into a pill counting machine as she fills a prescription while working at a pharmacy in New York December 23, 2009.

NEW YORK (Reuters Health) - More and more Americans are landing in the hospital due to poisoning by powerful prescription painkillers, sedatives and tranquilizers, according to a report released today. City-living middle-aged women seem particularly vulnerable.

"People have seen the headlines related to Heath Ledger, Michael Jackson, Anna Nicole Smith and they think that's tragic but maybe contained to Hollywood," Dr. Jeffrey H. Coben of West Virginia University School of Medicine in Morgantown told Reuters Health.

"But the fact of the matter is we are seeing, across the country, very significant increases in serious overdoses associated with these prescription drugs," Coben warned.

Between 1999 and 2006, US hospital admissions due to poisoning by prescription opioids, sedatives and tranquilizers rose from approximately 43,000 to about 71,000.

That increase of 65 percent is about double the increase observed in hospitalizations for poisoning by other drugs and medicines, Coben and colleagues found.

Opioids -- examples include morphine, methadone, OxyContin and the active ingredient in Percocet -- are powerful narcotic painkillers that can be habit-forming. Some examples of sedatives or tranquilizers include Valium, Xanax, and Ativan.

What's behind the rise in poisoning by prescription painkillers, sedatives and tranquilizers? "There is not any single cause," Coben said. "There is increasing availability of powerful prescription drugs in the community and attitudes toward their use tend to be different than attitudes toward using other drugs, especially among young people, who report that prescription drugs are easy to obtain, and they think they are less addictive and less dangerous than street drugs like heroin and cocaine."

Accidental - or unintentional -- poisoning by opioids, sedatives and tranquilizers rose by 37 percent during the 7-year study period, while unintentional poisonings by other substances increased by just 21 percent.

"Unintentional poisoning is now the second leading cause of unintentional injury death in the US," Coben and colleagues note in their report. Among people 35 to 54 years old, unintentional poisoning surpassed motor vehicle crashes as the leading cause of unintentional injury death in 2005.

Even people who take opioid painkillers for legitimate medical reasons are at risk of overdosing. In a study reported by Reuters Health earlier this year, researchers followed nearly 10,000 adults who had received at least three opioid prescriptions within 90 days to treat chronic pain like back pain. Of these, 51 experienced at least one overdose, and six died as a result. The researchers also found that the higher the painkiller dose, the more likely the patients were to overdose.

In the current study, Coben's team found that intentional poisonings - suicide, self-inflicted poisoning, or poisoning someone else -- from prescription opioids, sedatives, and tranquilizers more than doubled, from about 10,000 in 1999 to nearly 24,000 in 2006. That compared to just a 53 percent increase in intentional poisonings from other substances.

The biggest percent increase in hospitalizations for poisoning for a specific drug was a quintupling for methadone, according to the team's report published in the American Journal of Preventive Medicine. This may be due to the more than 10-fold increase in overall retail sales of this drug from 1997 to 2006, they state.

Poisoning by benzodiazepines such as Xanax and Ativan -- drugs that possess sedative, hypnotic, anti-anxiety, anticonvulsant and muscle relaxant activities -- rose 39 percent over the study period.

Poisoning by barbiturates, which also have sedative, hypnotic and anti-anxiety actions, actually fell 41 percent, as did hospitalizations for poisoning by antidepressants (a decrease of 13 percent).

Hospitalizations from prescription drug poisonings most often involved women 35 to 54 years old living in urban settings and most of the cases were unintentional, "although the intent of a large number of cases was undetermined," Coben and colleagues note in their report.

Their findings stem from a comprehensive look at the US Nationwide Inpatient Sample, a database that contains records for roughly 8 million Americans hospitalized annually.

"A multifaceted approach is needed" to stem the tide in poisoning by opioids, sedatives and tranquilizers, Coben said. "Doctors need to perhaps rethink the types and quantities of medications they are prescribing," he told Reuters Health. "And we need to get better messages out to the public in terms of the dangers associated with these medications and combinations of these medications that are being used."

"We also need to think about law enforcement strategies with regard to illegal markets for distributing prescription drugs," Coben said.

SOURCE: American Journal of Preventive Medicine, April 2010.