I'll bet you...

His meds were laced with AZT. He was taking AZT without realizing it. Otherwise he would have continued to get stronger using the best treatments from around the world as they are discovered while avoiding the toxic ones like AZT. The establishment just couldn't allow that to happen when, at the same time, patients who were being treated by the medical-pharmaceutical complex were dropping like flies, since it would expose them as the murderers they were/are. It would have been a piece of cake to infiltrate someone into his club to do the dirty deed. They had already tried to kill him with AZT once before. This is a brave movie. My already high admiration for Matthew McConaughey has taken a quantum leap.