Benzoquinolines

Quinagolide (, ), sold under the brand name Norprolac, is a selective dopamine D2 receptor agonist which is used to manage hyperprolactinemia. It has also been found to be effective in the treatment of breast pain. It is used in the UK, but it is not available in US.

Bexlosteride is a potent and noncompetitive inhibitor of the enzyme 5α-reductase related to finasteride and dutasteride. It is selective for the type I isoform of the enzyme. It advanced to Phase III clinical trials, but development was halted at that stage, and it was never marketed.

Izonsteride (developmental code name LY-320,236) is a selective inhibitor of the 5α-reductase, with dual effects on both the type I and type II isoforms of the enzyme. It was under development by Eli Lilly and Company and Fujisawa for the treatment of benign prostatic hyperplasia but was never marketed. Izonsteride may also be useful in the treatment of androgenic alopecia.