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P A R T 7
Drugs acting on the reproductive system
D
rugs that are used to affect the male reproductive
system include androgens (male steroid hormones),
anabolic steroids and drugs that act to improve penile
dysfunction. The male steroids are produced in the
testes and affect the entire male reproductive system
(Figure 41.1). Box 41.1 describes the effect of these
drugs across the lifespan.
ANDROGENS
Androgens
are male sex hormones and include testoster-
one, which is produced in the testes, and the androgens,
which are produced in the adrenal glands. Testosterone,
the primary natural androgen, is the classic androgen
in use today. It is used for replacement therapy in cases
Seminal
vesical
Prostate
Epididymis
Scrotum
Rectum
Ureter
Urinary bladder
Urethra
Corpus
cavernosum
Corpus
spongiosum
Glans
penis
Epididymis
(body)
Vas deferens
Epididymis
(body)
Epididymis
(body)
Seminiferous
tubules
Interstitial or Leydig cells
-hair growth
-baldness
-increased haematocrit
-muscle growth
-epiphyseal closure
-thicker bones
-thickening skin
-growth of genitalia
Testosterone
alprostadil, sildenafil,
tadalafil, vardenafil
work here
Testis
Sperm
Testis
danazol, mesterolone,
testosterone
work here
nandrolone
works here
FIGURE 41.1
Sites of action of drugs affecting the male reproductive system.
