Mortality in year after overdose lower with methadone or buprenorphine treatment

In the 12 months after nonfatal opioid overdose, treatment with methadone or buprenorphine was associated with 53% and 37% decreased odds of all-cause mortality, respectively, compared to no medication treatment for opioid use disorder, a recent study found.

Researchers used datasets from Massachusetts government agencies to assess mortality in 17,568 adults without cancer who survived an opioid overdose between 2012 and 2014. They identified exposure to methadone maintenance treatment, buprenorphine, and naltrexone at monthly intervals and examined the effect of the medications on all-cause and opioid-related mortality, adjusting for age, sex, baseline anxiety diagnosis, depression diagnosis, and other variables.

Results were published online on June 19 by Annals of Internal Medicine.

About 30% of survivors received medications for opioid use disorder in the 12 months after overdose: 2,040 (11%) enrolled in methadone maintenance treatment, for a median of five months (interquartile range, two to nine months); 3,022 (17%) received buprenorphine, for a median of four months (interquartile range, two to eight months); and 1,099 (6%) received naltrexone, for a median of one month (interquartile range, one to two months). About 5% of participants received more than one medication for opioid use disorder.

At 12 months, overall all-cause mortality was 4.7 per 100 person-years (95% CI, 4.4 to 5.0 per 100 person-years), and opioid-related mortality was 2.1 per 100 person-years (95% CI, 1.9 to 2.4 per 100 person-years). After adjustment, compared with no medications for opioid use disorder, methadone was associated with decreased all-cause mortality (hazard ratio [HR], 0.47; 95% CI, 0.32 to 0.71) and opioid-related mortality (HR, 0.41; 95% CI, 0.24 to 0.70). Buprenorphine was also associated with decreased all-cause mortality (HR, 0.63; 95% CI, 0.46 to 0.87) and opioid-related mortality (HR, 0.62; 95% CI, 0.41 to 0.92).

There was no association between naltrexone and all-cause mortality (HR, 1.44; 95% CI, 0.84 to 2.46) or opioid-related mortality (HR, 1.42; 95% CI, 0.73 to 2.79). However, the study authors noted that few events among those who received naltrexone precluded them from making firm conclusions.

They added that limitations of the study include its observational design, the likelihood of residual confounding, and the potential for data misclassification. They also noted the possibility of limited generalizability outside Massachusetts, a state with higher-than-average opioid-related mortality and insurance coverage.

The study highlights the underuse of effective medications for opioid use disorder and the need to increase treatment retention, according to an accompanying editorial.

“A great part of the tragedy of this opioid crisis is that, unlike in previous such crises America has seen, we now possess effective treatment strategies that could address it and save many lives, yet tens of thousands of people die each year because they have not received these treatments,” the editorialists wrote.