Q 1. Cimetidine at high doses given for long periods produces:
A. Gynaecomasia
B. Impotency
C. Loss of libido
D. All
Ans. D, Cimetidine is a histamine H2-receptor
antagonist that inhibits stomach acid production. It is largely used in the
treatment of heartburn and peptic ulcers. Cimetidine has also been found to
possess clinically significant anti-androgen properties at high doses that are
especially noticeable in men. It directly antagonizes the binding of
testosterone and DHT to the androgen receptor in animals.
Cimetidine's
anti-androgen properties likely explain certain side effects seen with it such
as galactorrhea and amenorrhea in women and gynecomastia and impotence in men.
