Hepatitis C cases spiked after Oxycontin reformulated to deter opioid abuse

New research finds one of the most successful moves to reduce the risk of prescription opioid abuse may have inadvertently led to a spike in hepatitis C infections, and potentially, healthcare costs.

The rate of hepatitis C infection in the U.S. had been relatively stagnant before 2010, according to a study published Monday in Health Affairs, even as the rate of death from prescription opioid overdose rose. That year, makers of the pain-reliever OxyContin changed the drug formula to make it less addictive.

A 2016 study in the journal Clinical Pharmacology & Therapeutics found the abuse-deterrent form of OxyContin led to a 48% reported decline in its misuse and a 65% drop in overdose deaths reported to the manufacturer over three years after the drug was reformulated.

But the most recent study suggests the switch caused some people who had been misusing OxyContin to try heroin, leading to more needle-sharing and higher risks of exposure to hepatitis C, which killed an estimated 20,000 people in 2015, according to the Centers for Disease Control and Prevention.

RAND Corp. researchers found that hepatitis C infections rose 222% in states that had above-average rates of OxyContin misuse prior to the reformulation. States with below-average OxyContin misuse had a 75% increase in hepatitis C infections after the drug was changed. States with above average OxyContin misuse and below average OxyContin misuse had similar rates of hepatitis C infection prior to reformulation of the drug.

Hepatitis C costs the U.S. an estimated $10 billion a year in direct and indirect healthcare costs.

"Even if we somehow managed to stop overdoses tomorrow, now we have all these people who have these really bad infectious diseases that are deadly and are incredibly expensive," said David Powell, the study's lead author and a senior economist at RAND. "Those are going to be consequences we haven't really quantified before of the opioid crisis."

Powell believes the study underscores the importance of substance abuse treatment.

"If you're going to take away the drug that people have been misusing, you need to give them an alternative," Powell said. "Providing more access to substance-abuse treatment can potentially help them from not turning to illicit markets."

The study found the rise in hepatitis C cases was unique to previous OxyContin users and did not find similar changes in disease rates associated with other painkillers. Researchers said the findings suggest that the reformulation—and not other drug control policies—drove the rise in infections.

Powell worries efforts to deter opioid misuse can lead to unintended, yet long-term public health consequences. More than 70,000 drug overdose deaths occurred in 2017, according to the CDC. And while the number of deaths from prescription opioids has begun to plateau, overdose deaths from heroin and fentanyl are climbing. Powell believes the reformulation probably caused other infectious diseases to rise even though they were not studied.

The CDC has linked the opioid crisis with an increased risk of acquiring a number of blood-borne infections, including hepatitis B and HIV, and heart infections caused by bacteria. Those transmissions also raise concerns about the spread of antimicrobial-resistant pathogens.

Powell felt the study's findings showed the importance of having drug control policies that address reducing the demand for drugs as much as it focuses on eliminating the supply.

"This should sort of tilt our policymakers toward thinking less about supply-side interventions and more about demand-side treatments," Powell said.