Quinacrine hydrochloride. Review and mode of action of an antimalarial, used as an occlusive agent for transvaginal human sterilization.

Quinacrine hydrochloride, mainly used as an antimalarial, has been used as a nontoxic chemosterilant in a transvaginal procedure in the human female. Clinical experiments indicate that Quinacrine acts as a powerful obstructive agent exclusively on the epithelium of the intramural portion of the tube without alterating the histology of the endometrium. The precise mechanism of Quinacrine's obstructive action on the mucosa of the uterotubal junction is unknown. Its possible mode of action is binding to epithelial DNA thus forming a clot of granulomatous tissue, as Quinacrine is known to form adhesions when used in the control of neoplastic effusions. Zinc is known to inhibit Quinacrine-DNA binding. The human endometrium, rich in Zinc is unaffected by Quinacrine, whereas the tubal cornua, with little Zinc promote the obstruction by Quinacrine DNA bondage. The procedure is effective in 90 per cent of the cases with two instillations of Quinacrine. Further studies are essential to find agents that would potentiate the action of Quinacrine on the human Fallopian tube epithelium.