Tolerability studies are medium to long term dosing studies that establish the tolerability of a compound after initial acute toxicology studies have established an LD50. The goal of these studies is to determine how much drug can be given on a daily basis for an extended period in order to determine how much can be given in efficacy studies. In a standard protocol, animals are dosed for 14 days and then either serum chemistries are performed to look for signs of specific organ toxicity, or the animals are evaluated for an additional 7-14 days to evaluate delayed toxicity. End points are weight change and survival.