Buprenorphine and naloxone are commonly combined in opiate substitution therapies, such as BNX. Buprenorphine is a partial mu-opioid receptor agonist. This means that it partially fills the opioid receptors, both blocking the euphoric effects of other opioids and decreasing cravings. Although buprenorphine has some opioid effects, the effects cap off at a certain level so increasing the dose does not have an additional effect. Naloxone counteracts the effects of opioids.
This research study by Jonsson and colleagues collected pharmacokinetic data (data about the drugs’ movement in the body) for the rapidly dissolving buprenorphine formulation. The goal was to determine the bioequivalence and bioavailability of two different doses of the rapidly dissolving tablets. Additionally, the researchers measured dissolve times and the participants assessed the drugs’ taste and mouthfeel.
Two groups of healthy volunteers were given a medicine which blocks the effects of the opioids. Then, they received a single dose of BNX-RDT or BNX. The high dose group received either 11.4/2.9 mg of BNX-RDT or 16/4 mg of BNX. The low dose group received either 2.9/ 0.71 mg of BNX-RDT or 4/1 mg of BNX. The drug concentrations in the blood were measured after 72 hours.
Key Research Findings
When a drug is more bioavailable, less of it is needed to achieve the desired effect. The new formulation improved the bioavailability of all of the different doses. Additionally, the activity of the BNX-RDT was more proportional across its strengths than the activity of the BNX.
Rapid Dissolve Times
The rapidly dissolving formulation is more convenient for patients, who have to hold the wafer under their tongues for extended time periods. The high dose BNX-RDT’s average dissolve time was 8.5 minutes compared to 16.2 minutes for BNX. The low dose BNX-RDT’s average dissolve time was 7.6 minutes compared to 8.1 minutes for BNX. However, there was a lot of variation between the dissolve times, which ranged from 2 to 42 minutes.
This rapid dissolve time, in addition to improvements in taste, mouthfeel, and overall palatability led 78% of participants to prefer BNX-RDT to BNX.
Although it was not assessed in this study, the BNX-RDT tablets affected the patients considerably faster than the BNX tablets. Some patients may benefit from a more rapidly-acting way to ease their cravings. However, this rapid action may provide a bit of a rush, which would have adverse effects on people’s recoveries. Much of the pushback to medication-assisted treatments for opiate use disorders is because the medications are opiates themselves and some people in recovery may not want to become dependent on other pills.
Value and Access to Care
It is unclear if the new buprenorphine formulation’s value is primarily to the consumers or the pharmaceutical companies. Pharmaceutical companies often create new formulations of drugs to extend the lives of their products beyond when generic versions of the products become available. Additionally, this formulation was patented by Richard Sackler of Purdue Pharmaceuticals, the company famous for originally introducing OxyContin to the market. Although the improvements in the taste, dissolve time, and bioavailability are considerable, the drug’s effects are fundamentally the same. Also, a new formulation will likely come with a higher price tag.
Currently, buprenorphine is prohibitively expensive to many people in recovery, especially those who lack insurance or have high deductibles. Doctors may be hesitant to prescribe buprenorphine because of the misinformation and stigma surrounding addiction and medication-assisted recovery. Approximately 46,500 (about 5%) of doctors in the United States have received buprenorphine training, which only takes 8 hours to complete. Buprenorphine use may be more widespread if more doctors were able to prescribe it. The new formulation of buprenorphine will not change the fact that the medication is often unavailable to those who need it the most.
Primary study: Jönsson, Mundin, & Sumner. (2018). Pharmacokinetic and pharmaceutical properties of a novel buprenorphine/naloxone sublingual tablet for opioid substitution therapy versus conventional buprenorphine/naloxone sublingual tablet in healthy volunteers. European Journal of Pharmaceutical Sciences, 122, 125-133.