Toxic effects of propylthiouracil in the rat

Repeated intraperitoneal administration of propylthiouracil (PTU, 0.5-1.5 mmole/Kg) to rats caused a dose related decrease in body weight. A dose dependent increase in liver weight and a decrease in spleen weight were also seen. Leukocyte counts were markedly reduced in all PTU treated animals. Histopathological changes were observed. These consisted of congestion of red pulp of the spleen and vacuolization of the liver.