Probuphine was evaluated in two placebo-controlled trials. In terms of efficacy, researchers found that patients on the active implant were more likely than those given a placebo implant to have opioid-negative urine samples on more occasions, and were less likely to need sublingual buprenorphine for treating of symptoms of withdrawal or craving.
But the response “was not what one might hope for, given that the product ensures compliance with medication for 6 months,” the researchers wrote. “It prompts speculation that the dose is simply not high enough.”
For instance, only 32% and 27% of patients in the respective trials had opioid-negative samples for half of all their urine tests, and 40% to 62% needed supplemental buprenorphine.
Of course, their theory is that the dose is too low.