Factors Affecting Buprenorphine Utilization and Spending in Medicaid, 2002-2018

Retrospective study investigating naloxone prescribing and cost in US Medicaid and Medicare patients

BACKGROUND

Opioid overdoses in the USA have increased to unprecedented levels. Administration of the opioid antagonist naloxone can prevent overdoses.

OBJECTIVE

This study was conducted to reveal the pharmacoepidemiologic patterns in naloxone prescribing to Medicaid patients from 2018 to 2021 as well as Medicare in 2019.

DESIGN

Observational pharmacoepidemiologic study SETTING: US Medicare and Medicaid naloxone claims INTERVENTION: The Medicaid State Drug Utilisation Data File was utilised to extract information on the number of prescriptions and the amount prescribed of naloxone at a national and state level. The Medicare Provider Utilisation and Payment was also utilised to analyse prescription data from 2019.

OUTCOME MEASURES

States with naloxone prescription rates that were outliers of quartile analysis were noted.

RESULTS

The number of generic naloxone prescriptions per 100 000 Medicaid enrollees decreased by 5.3%, whereas brand naloxone prescriptions increased by 245.1% from 2018 to 2021. There was a 33.1-fold difference in prescriptions between the highest (New Mexico=1809.5) and lowest (South Dakota=54.6) states in 2019. Medicare saw a 30.4-fold difference in prescriptions between the highest (New Mexico) and lowest states (also South Dakota) after correcting per 100 000 enrollees.

CONCLUSIONS

This pronounced increase in the number of naloxone prescriptions to Medicaid patients from 2018 to 2021 indicates a national response to this widespread public health emergency. Further research into the origins of the pronounced state-level disparities is warranted.

The Impact of Suboxone's Market Exclusivity on Cost of Opioid Use Disorder Treatment

BACKGROUND

Buprenorphine-naloxone is an essential part of the response to opioid poisoning rates in North America. Manipulating market exclusivity is a strategy manufacturers use to increase profitability, as evidenced by Suboxone in the USA.

OBJECTIVE

To investigate excess costs of buprenorphine-naloxone due to unmerited market exclusivity (no legal patent or data protection) in Canada.

METHODS

Using controlled interrupted time-series, this study examined changes in the cost of buprenorphine-naloxone before and after the first generics were listed on public formularies. Methadone cost was the control. Public data from the Canadian Institute of Health Information in British Columbia, Manitoba, and Saskatchewan were used. All buprenorphine-naloxone and methadone claims (2010-2019) accepted for payment by the provincial drug plan/programme were collected. Primary outcome was mean cost per mg of buprenorphine-naloxone after the first listing of generics.

RESULTS

Mean cost per mg of buprenorphine-naloxone before the first listing of generics was $1.21 CAD in British Columbia, $1.27 CAD in Manitoba, and $0.85 CAD in Saskatchewan. Following the introduction of generics, the cost per mg decreased by $0.22 CAD (95% CI - 0.33 to - 0.10; p = 0.0014) in British Columbia, $0.36 CAD (95% CI - 0.58 to - 0.13; p = 0.004) in Manitoba, and $0.27 CAD (95% CI - 0.50 to - 0.05; p = 0.03) in Saskatchewan. Mean cost per mg decreased by $0.26 CAD (95% CI - 0.38 to - 0.13; p = 0.0004) after a third generic was introduced in British Columbia. Excess costs to public formularies during the 4- to 5-year period prior to the listing of generics were $1,992,558 CAD in British Columbia, $80,876 CAD in Manitoba, and $4130 CAD in Saskatchewan. If buprenorphine-naloxone cost $0.61 CAD (mean cost after the third generic entered) instead of $1.21 CAD per mg during the pre-generics period, public payers in British Columbia could have saved $5,016,220 CAD between 2011 and 2015.

CONCLUSIONS

Unmerited 6 years of market exclusivity for brand-name buprenorphine-naloxone in Canada resulted in substantial excess costs. There is an urgent need to implement policies that can help reduce costs for high-priority drugs in Canada.