The Substance Abuse and Mental Health Services Administration (SAMHSA) is prominently displaying on its website an advisory outlining a number of prescribing considerations associated with use of extended-release injectable naltrexone to treat opioid dependence. The eight-page document features a table that highlights differences between injectable naltrexone (sold under the brand name Vivitrol) and the medications buprenorphine and methadone, including that Vivitrol is the only one of the three drugs with no diversion and abuse potential.
The opening paragraph of the advisory states about Vivitrol, which was federally approved for the treatment of opioid dependence in the fall of 2010, “This medication provides patients with opioid dependence the opportunity to take effective medication monthly, as opposed to the daily dosing required by other opioid dependence medications.” Vivitrol has been used in the treatment of alcohol dependence since 2006.
The document also addresses safety risks that Vivitrol shares with the other opioid dependence treatments (such as accidental overdoses among some individuals who take opioids while on the medication treatment), as well as risks exclusive to the injectable medication for opioid dependence (such as injection site reactions that in some cases have warranted surgery).
SAMHSA on March 21 did not reply to e-mailed questions from Addiction Professional to elaborate on the context and timing of the advisory’s release. The advisory is titled “An Introduction to Extended-Release Injectable Naltrexone for the Treatment of People With Opioid Dependence.”
SAMHSA states that while generalizations about which patient will fare best under a certain medication are difficult to make, the opioid antagonist properties of naltrexone might make Vivitrol’s anti-craving effects particularly successful for individuals who are facing high levels of stress and relapse risk.
Other groups that might benefit most from Vivitrol, according to the advisory, include individuals who have not had success with methadone or buprenorphine treatment; those who have succeeded with agonist therapies but might prefer a more convenient and less stigmatized treatment; and those who have a high level of motivation for abstinence.
The advisory also cites Vivitrol as a possible alternative for adolescents or young adults who have limited access to the other medication therapies, though it adds that the Food and Drug Administration (FDA) has not approved Vivitrol for use in patients under 18.
The advisory’s side-by-side comparison of Vivitrol, buprenorphine and methadone also highlights a number of other distinct features about Vivitrol, including that prescribing non-physicians such as nurse practitioners are allowed to order its administration.
The advisory’s section on adverse events focuses mainly on injection site reactions from the gluteal intramuscular injection and on liver toxicity. The document recommends always administering Vivitrol injections using the specially designed 1.5- or 2-inch needles included in the medication packaging, and the document also cites warnings on the medication labeling about the risk of liver effects when Vivitrol dosing exceeds recommended levels.
Regarding access to the respective medications available in the market, the advisory mentions the limited geographical locations of methadone clinics and the relative lack of physicians specially trained to prescribe buprenorphine.
SAMHSA adds, citing a 2011 study, “Extended-release injectable naltrexone has a higher pharmacy cost than buprenorphine and methadone, but some data suggest that its use may reduce inpatient admissions, emergency room visits, and other health system costs. Nonetheless, the higher pharmacy cost of extended-release injectable naltrexone may limit access for patients who lack health insurance or other financial resources.”