Opioid Painkiller 1,000 Times Stronger Than Morphine Approved by FDA The new painkiller called Dsuvia is currently restricted to limited use in healthcare settings. Approved on Friday by the Food and Drug Administration (FDA), Fentanyl has been linked to thousands of overdose deaths in what is widely regarded as an opioid epidemic in the U.S. FDA Commissioner Scott Gottlieb states the drug should not be used for more than 72 hours. The single dose medication dissolves under the tongue. On the same day as Dsuvia's approval, The DEA's reports states that since 2001, Listed side effect of Dsuvia include extreme tiredness, breathing problems, coma and death.