Extensively metabolized in the liver and kidneys. It is extensively metabolized by cytochrome P450 isozymes CYP2D6 (major pathway), CYP1A2 and CYP3A4. Approximately 10 to 12 major metabolite have been identified. Hydroxylation at positions 3 and 7 of the phenothiazine nucleus and the N-dimethylaminopropyl side chain undergoes demethylation and is also metabolized to an N-oxide. In urine, 20% of chlopromazine and its metabolites are excreted unconjugated in the urine as unchanged drug, demonomethylchlorpromazine, dedimethylchlorpromazine, their sulfoxide metabolites, and chlorpromazine-N-oxide. The remaining 80% consists of conjugated metabolites, principally O-glucuronides and small amounts of ethereal sulfates of the mono- and dihydroxy-derivatives of chlorpromazine and their sulfoxide metabolites. The major metabolites are the monoglucuronide of N-dedimethylchlorpromazine and 7-hydroxychlorpromazine. Approximately 37% of the administered dose of chlorpromazine is excreted in urine.
In some literature articles, the term mechanism of action and mode of action (MoA) are used interchangeably; typically referring to the way in which the drug interacts and produces a medical effect. However, in actuality, a mode of action describes functional or anatomical changes, at the cellular level, resulting from the exposure of a living organism to a substance.  This differs from a mechanism of action, as it is a more specific term that focuses on the interaction between the drug itself and an enzyme or receptor and its particular form of interaction, whether through inhibition , activation , agonism , or antagonism . Furthermore, the term mechanism of action is the main term that is primarily used in pharmacology, whereas mode of action will more often appear in the field of microbiology or certain aspects of biology.