Wouldn't it nice if one dose of medicine could be used over and over? The was the premise behind the everlasting cathartic pill. It was made of metal, and leeched out antimony as it passed through the digestive system, aiding in the elimination of parasites. It was billed as a cathartic, or laxative as we would say today. And the pill could be recycled! According to a 1907 pharmaceutical guide:
The bullet was passed out, recovered from the feces and used over and over again. This, as Dr. J. A. Paris says, was economy in right earnest, for a single pill would serve a whole family during their lives and might be transmitted as an heirloom to posterity.
Some heirloom! Link