None of the clinical trials for opioids the FDA approved to treat chronic pain from 1997 to 2018 lasted longer than three months, according to research published Sept. 29 in Annals of Internal Medicine.
Researchers discovered that only 21 of the 39 opioids approved by the FDA from 1997 to 2018 were supported by at least one pivotal trial. The median length of the trials conducted for opioids during this time was 84 days.
The study also found that of the 21 products backed by a pivotal trial, 17 (81 percent) excluded participants who could not tolerate the drugs, and most trials failed to examine risks associated with tolerance, addiction and drug diversion. Its conclusion states that "systematic collation of certain important safety outcomes was rare."