Table 2.

Different drugs used as androgen inhibitors for prostate cancer treatment.

Drug Category	Compound	Chemical Structure	Mechanism of Action
First-generation antiandrogen	Bicalutamide	Nonsteroidal antiandrogen	It blocks the effects of androgens at AR level
First-generation antiandrogen	Flutamide	Nonsteroidal antiandrogen	It blocks the effects of androgens at AR level
First-generation antiandrogen	Nilutamide	Nonsteroidal antiandrogen	It blocks the effects of androgens at AR level
First-generation antiandrogen	Cyproterone	Derivative of progesterone	It binds to AR and blocks the effects of testosterone and DHT
GnRH Agonist	Leuprorelin	Synthetic analog of gonadotropin-releasing hormone (GnRH)	It binds with high affinity to GnRH receptor on anterior pituitary cells, where it acts as an agonist
GnRH Agonist	Triptorelin	Synthetic analog of GnRH: more potent than native hormone and more resistant to proteolysis	It binds with high affinity to GnRH receptor on anterior pituitary cells, where it acts as an agonist
GnRH Agonist	Goserelin	Synthetic analog of GnRH: more potent than native hormone and more resistant to proteolysis	It binds with high affinity to GnRH receptor on anterior pituitary cells, where it acts as an agonist
GnRH Agonist	Degorelix	Synthetic peptide derivate of GnRH	It binds with high affinity to GnRH receptor on anterior pituitary cells, where it acts as an agonist
GnRH Agonist	Relugolix	Synthetic nonpeptide analog of GnRH	It binds with high affinity to GnRH receptor on anterior pituitary cells, inhibits the secretion of FSH and LH, preventing the release of testosterone by Leidig cells
Second-generation androgen inhibitors	Abiraterone	Steroidal compound inhibitor of androgen synthesis	It blocks the enzyme cytochrome P450 1 alpha-hydroxylase (CYP17), an enzyme required for testosterone synthesis
Second-generation androgen inhibitors	Enzalutamide	Synthetic AR signaling inhibitor	It blocks AR signaling at three key stages: it blocks the binding of androgens to AR, it inhibits nuclear translocation of activated AR and impairs binding of activated AR with DNA
Second-generation androgen inhibitors	Apalutamide	Small molecule synthetic AR antagonist	It selectively binds to the ligand-binding domain of AR and blocks nuclear translocation and binding to androgen response elements
Second-generation androgen inhibitors	Darolutamide	Nonsteroidal AR antagonist	It selectively binds to the ligand-binding domain of AR and blocks nuclear translocation and binding to androgen response elements
Second-generation androgen inhibitors	Galeterone	Steroidal compound inhibitor of androgen synthesis	It blocks the enzyme CY17, acts as an AR antagonist, promotes AR degradation
Second-generation androgen inhibitors	EPI-506	Nonsteroidal small molecule AR antagonist	It selectively binds to the NTD of AR and blocks AR signaling