Tales from the Crypt - Season 4 Episode 2
This'll Kill Ya

Sophie and Pack are workers at a medicine company. They are furious when their boss tells the papers that they are ready to test their new drug on humans. One day, while he is taking his shots they accidently inject him with the serum. George has only a few hours to live. He starts to have delusions and learns hes been set up and kills Pack. Sophie bursts in and tells him that the whole thing was just a joke.