Vasokin
An experimental drug designed to increase blood supply to the humanoid organs, although 22% of its test cases developed severe damage to the lungs, kidneys and heart -- even the brain. Bareil chose the short-term relief to get through the Bajoran-Cardassian peace talks rather than long-term stasis for a more sure cure, and damage does set in. Doctor Bashir replaced the organs until it massively damaged synapses in his brain's left parietal lobe, and he in effect sacrifices himself for the world whose kaiship he had to abandon.
