The growing market for opioid treatment drugs has created fierce competition between drug manufacturers and the results from a long-awaited study are in. The study, funded by the federal government, compared Vivitrol and Suboxone and found that both are similarly effective. Fifty-two (52%) percent of those who started on Vivitrol relapsed during the 24-week study, compared with fifty-six (56%) percent of those who started on Suboxone. But the study also found a substantial hurdle for Vivitrol because the medication can be started only after a person is completely detoxed from opioids. More than a quarter of the study participants assigned to Vivitrol dropped out before being able to take their first dose. Suboxone can be started shortly after withdrawal symptoms begin, and only six percent of those assigned to take that drug dropped out before taking an initial dose. Vivitrol is the most expensive addiction medication; $500-$1,000 per shot, Suboxone is about third to half as much with Methadone being the least expensive of the available drugs for opioid addiction. Alkermes has pushed for the use of Vivitrol in drug courts and jails, where Suboxone is often not allowed and has won fans among many law enforcement officials who see Suboxone as simply replacing one addiction for another. Suboxone is also more likely to be diverted into a black market. But Alkermes’ strategy has drawn attention from lawmakers and Senator Kamala Harris of California, announced a Senate committee investigation into the company’s “sales, marketing and educational” tactics, which she said had attempted to artificially boost sales by stigmatizing treatments like Suboxone. But Suboxone, which has more market share than any other addiction medication, has also come under scrutiny. Its maker has been sued by 43 state attorneys general who say the company schemed to block generic competition by conspiring with another company to create a slightly different delivery system for the drug. The new study was published in The Lancet and is only the second to compare the drugs. A study conducted in Norway and released last month had similar results, but it was shorter and included fewer patients.