By Pat Anson, Editor

Prescription drug monitoring programs (PDMPs) have long been promoted as a critical tool in the fight against opioid abuse and overdoses. PDMP’s in 49 states and the District of Columbia allow physicians and pharmacists to consult a prescription drug database to see if patients might be “doctor shopping” or selling their opioid medication.

But a new study has found little evidence that PDMPs are working and that they may in fact be driving some patients to the black market for cheaper drugs such as heroin.

Researchers at Columbia University's Mailman School of Public Health and University of California, Davis, analyzed 17 studies that looked at the effectiveness of PDMPs. Their findings are published online in the Annals of Internal Medicine.

“Evidence that PDMP implementation either increases or decreases nonfatal or fatal overdoses is largely insufficient, as is evidence regarding positive associations between specific administrative features and successful programs. Some evidence showed unintended consequences,” wrote lead author David Fink, MPH, a doctoral candidate in epidemiology at the Mailman School of Public Health.

What were those unintended consequences? Three studies that looked at heroin related overdoses found a “statistically significant” increase in heroin deaths after PDMPs were implemented.

"This suggested to us that heroin substitution may have increased after PDMP-inspired restrictions on opioid prescribing," says Silvia Martins, MD, a professor of epidemiology at Mailman and co-senior author. "We therefore caution that programs aimed at reducing prescription opioids should also address the supply and demand of illicit opioids."

Researchers believe that efforts to reduce doctor shopping and the diversion of prescription opioids may have backfired.

“A reduction in black market prescription opioids, although generally viewed as positive, also may generate unanticipated outcomes. For example, an ethnographic study of high-risk users in Philadelphia and San Francisco found that key drivers of the progression from prescription opioid to heroin use are the rising cost of the ‘pill habit’ and heroin’s easy availability and comparatively lower cost,” Fink said.

Heroin overdoses also rose after Purdue Pharma introduced a new and more expensive abuse deterrent formulation of OxyContin in 2010. According to one study, each death that was prevented by OxyContin's reformulation “was replaced with a heroin death.”

Fink and his colleagues say more studies are needed to examine the true effectiveness of PDMPs, which can vary widely from state to state.

Doctor Shopping Rare

Missouri is the lone state that has not adopted a statewide PDMP and one family physician would like to keep it that way.

In an unpublished study, John Lilly, DO, claims that PDMPs are not working because doctor shopping is rare to begin with. In 2016, doctor shopping was responsible for only 1.7% of all misused opioid prescriptions. The rest are stolen, borrowed or bought on the black market, or misused by the patients they were prescribed to.

“The prescription drug monitoring programs will never catch the remaining 98.3 percent of the problem. That is why the death rate has not decreased despite 49 states having an operational PDMP,” Lilly wrote.  “There is now an alternative to prescription drugs that is easier to obtain and more powerful. Illicit fentanyl is now the preferred opioid and the PDMPs have absolutely no effect on its rapid rise. I would not be surprised if prescription opioid deaths start to fall, not due to the effectiveness of the PDMPs, but due to market competition from illicit fentanyl.”

If PDMP's were effective, Lilly says states that have them would see a decline in opioid overdoses. But in 2016, West Virginia had the highest opioid death rate in country -- over three times higher than Missouri's -- which ranked 25th.

Missouri’s Governor ordered the creation of a statewide PDMP last year, but the state legislature has so far resisted efforts to fund it. Critics say it doesn’t give doctors the necessary tools to prevent overprescribing, but allows law enforcement to track and prosecute physicians and pharmacists.  A spokesman for the Missouri State Medical Association called the program a “witch hunt against physicians.”