
Over more than two decades, the Food and Drug Administration approved opioid painkillers based on relatively brief pivotal clinical trials that relied on narrowly defined patient groups and rarely assessed key safety outcomes, according to a new study.
Specifically, the study found that, for opioids approved between 1997 and 2018 as treatments for chronic pain, none of the trials lasted longer than three months. Moreover, the trials often excluded patients who could not tolerate the painkillers and generally failed to systematically evaluate such known risks as tolerance, drug diversion and so-called non-medical uses.