Extended-Release vs. Oral Naltrexone Alcohol Treatment in Primary Care

Rationale: Though integration of alcohol pharmacotherapy into primary care settings is receiving increasing emphasis and support, rigorous data to inform clinicians' treatment choice is lacking. The most recently FDA-approved alcohol treatment medication, an extended-release depot form of naltrexone (XR-NTX, Vivitrol®), could greatly simplify the medical home-centered alcohol treatment emphasized in the National Institute on Alcohol Abuse and Alcoholism (NIAAA) Clinician's Guide. Injected once a month, XR-NTX offers a long-acting and thus potentially more effective form of pharmacotherapy than oral naltrexone (O-NTX), which, despite the Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) trial and systematic reviews supporting some efficacy, has been characterized by low rates of overall prescribing, poor adherence, suboptimal monthly refill and inadequate treatment retention. Yet while promising as an alternative to O-NTX, XR-NTX is substantially more expensive (~$1100 vs. ~$100 per month), and no head-to-head trials have compared the two forms of naltrexone. A comparative effectiveness approach is required to systematically evaluate the following key questions: In primary care settings, what is the relative clinical effectiveness of XR-NTX vs. O-NTX? What are the benefits and costs of XR-NTX relative to O-NTX? And can patient and system characteristics be identified to inform treatment choice to maximize the probability of successful outcome?

Implications: Despite several years of experience, the comparative effectiveness of XR-NTX compared to older alcohol medications remains uncertain, particularly in a mainstream, primary care treatment model that is generalizable and broadly accessible. Newer, novel, expensive medications for addiction disorders are historically greatly underutilized by primary care physicians. This study is innovative both as a 'head-to-head' evaluation of XR-NTX vs. O-NTX in primary care, and because expected participants will be primarily Medicaid-covered or uninsured persons who will not be excluded based on medical and psychiatric co-morbidities that often preclude participation in efficacy studies. If health insurance expansion, parity reforms, medical homes and accountable care organizations are to define primary care as a core alcohol treatment setting in the coming decade, exactly this type of study is required to guide treatment protocols and resource allocation. Ultimately, more widespread adoption of cost-effective alcohol pharmacotherapies will result in longer,healthier lives and lower costs.