Metabolism of phenothiazine in the guinea pig

The metabolism of phenothiazine was studied in the guinea pig. In the adult animal after 24 hr, about 7% of the administered dose was found in feces, with traces of the sulfoxide and phenothiazone. Small amounts of all these compounds also were found in urine, with leucophenothiazone sulfate (approximately 12%) and a metabolite identified as phenothiazine N-glucuronide (approximately 22%). This latter compound was also present in bile. Both phenothiazine and its sulfoxide were retained in body tissues for a long time, about 85% of the dose being excreted after 7 days. In neonatal animals, phenothiazine, with up to 12% of the sulfoxide together with traces of leucophenothiazone, phenothiazone, and thionol was excreted in urine.