| It is working on a version containing naltrexone, an opiate antagonist that would block oxycodone's euphoric effects once the pill was crushed. |
| Nalmefene, another opioid antagonist, is similar to naltrexone but without FDA approval for treatment of alcohol dependence. |
| Since the claw flexor muscle in insects has no antagonist, claws and arolium are moved back by elastic recoil of stretched exocuticle. |
| The screen comes alive when either the protagonist, or his worthy antagonist, are present. |
| The bear, wolf, coyote, fisher, wolverine, otter, and lynx prey upon the beaver who is, nevertheless, a powerful antagonist when at bay. |
| Small studies have suggested that the opiate antagonist naltrexone is effective as an adjuvant therapy for treating alcohol addiction. |
