 SANTA MONICA, Calif., April 05, 2021 GLOBE NEWSWIRE -- Opiant Pharmaceuticals, Inc. Opiant NASDAQ: OPNT, a specialty pharmaceutical company developing medicines to treat addictions and drug overdose, today announced that the first subjects were dosed in a head-to-head clinical study comparing the effectiveness of its investigational opioid antagonist OPNT003, nasal nalmefene, with nasal naloxone. 