By Pat Anson, Editor

The vast majority of chronic pain patients continue to be prescribed opioids after a non-fatal overdose, usually from the same doctor who prescribed the pain medication that led to the overdose, according to new research published in the Annals of Internal Medicine.

In the study of nearly 2,850 patients who were treated for an opioid overdose, 91% were prescribed another opioid within 300 days of the overdose. About 70% of the prescriptions were written by the same provider. Data for the study was collected from insurance claims filed from 2000 to 2012.

"Our finding that almost all patients continue to be prescribed opioids after overdose is highly concerning,” wrote lead author Marc Larochelle, MD, Boston Medical Center. “The overdoses we detected were captured in routine claims data and treated in emergency departments or inpatient settings and thus represent identifiable events when information sharing might lead to improved care and outcomes. Further research is needed to determine whether providers continuing to prescribe opioids after an overdose are aware of the event and, if so, how they respond in counseling patients.”

The researchers found that about 7% of pain patients had a second overdose and those who were prescribed high doses of opioids had twice the risk of a repeat overdose.

Even more disturbing is that over half of the overdose patients (58%) were prescribed benzodiazepines, anti-anxiety medication that includes brand names such as Valium and Xanax.

Benzodiazepines are known to greatly increase the chances of an overdose. A recent CDC study found that about 80% of unintentional overdose deaths associated with opioids also involved benzodiazepines.

Due to limits in the data, researchers had no way of knowing why physicians continued to prescribe opioids after their patients overdosed.

“We could not determine reasons for the treatment patterns after the overdose; however, some prescribers may have been unaware that the opioid overdose had occurred,” said Larochelle. “In some cases, overdoses may have reflected therapeutic error rather than opioid misuse. In these and other cases, providers may have believed that the risk–benefit ratio favored continued opioid prescribing.”

In an editorial published in the Annals of Internal Medicine, Jessica Gregg, MD, called the study’s findings “astonishing.”

“Prescribing guidelines are clear that adverse events, such as overdose, are compelling reasons to withdraw prescription opioids. Therefore, it is tempting, and it would be easy, to attribute these results to poor care, bad decisions, or sloppy prescribing,” wrote Gregg, who is an associate professor of medicine at Oregon Health & Science University. “However, the problem goes well beyond individual prescribers' practices. These prescribing behaviors occur in a context in which substantial -- even deadly -- mistakes are inevitable. For instance, it is likely that many of the prescribers in the study did not know about their patients' overdoses.

“There are currently no widespread systems in place, either within health plans or through governmental organizations, for notifying providers when overdoses occur. Until such systems exist, providers will be left to act with dangerously limited knowledge. They will be unlikely to decrease or withdraw a patient's opioid prescription after an overdose if they have no knowledge that the event occurred.”

To make doctors more aware that their patients may have had overdoses, the researchers recommend that overdose data be included in prescription drug monitoring programs (PDMPs) which are now currently used to track prescriptions.