C H A P T E R 4 1
Drugs affecting the male reproductive system
629
of
hypogonadism
(underdeveloped testes) and to treat
certain breast cancers. The usual dosages and indica-
tions can be found in Table 41.1.
Therapeutic actions and indications
The androgens are forms of testosterone. They are
responsible for the growth and development of male
sex organs and the maintenance of secondary sex
characteristics. They act to increase the retention
of nitrogen, sodium, potassium and phosphorus
and to decrease the urinary excretion of calcium.
Testosterones increase protein anabolism and decrease
protein catabolism (breakdown). They also increase
the production of red blood cells. Hence, they can also
be used for delayed male puberty or hypogonadism.
Testosterone is long acting and is available in several
forms, including depot (deep, slow-release) injections
and a dermal patch. Mesterolone (
Proviron
) is an
androgen derivative available in oral form. Danazol, a
synthetic androgen, is also long-acting but is available
only in oral form.
Pharmacokinetics
The androgens are well absorbed and widely distrib-
uted throughout the body. They are metabolised in the
liver and excreted in the urine. It is not known whether
androgens enter breast milk (see Contraindications and
cautions).
BOX 41.1
Drug therapy across the lifespan
Drugs affecting the male reproductive system
CHILDREN
These drugs are used in children as replacement therapy
and to increase red blood cell production in renal failure.
Because of the effects of these hormones on epiphyseal
closure, children should be closely monitored with hand
and wrist radiographs pretreatment and every 6 months.
If precocious puberty occurs, the drug should be stopped.
Adolescents who are prescribed androgens should
be alerted to the potential for increased acne and other
effects.
Adolescent athletes need constant education about
the risks associated with the use of anabolic steroids
to improve athletic prowess and the lack of scientific
evidence of beneficial effect.
ADULTS
Adults also need reinforcement of the information about
anabolic steroid use and athletics.
Women who are prescribed these drugs may
experience masculinising effects and may need support in
coping with these body changes. Men who are receiving
these drugs for replacement therapy may need to learn
self-injection techniques and may benefit from information
on depot forms or dermal systems. Periodic liver function
tests are important in monitoring the effects of these drugs
on the liver.
PREGNANCY AND BREASTFEEDING
These drugs are not indicated for use in pregnancy or
breastfeeding because of the potential for serious effects
on the male fetus or neonate.
OLDER ADULTS
Older adults may have problems with androgen therapy
because of underlying conditions that are aggravated by
the drug effects. Hypertension, heart failure and coronary
artery disease may be aggravated by the fluid retention
associated with these drugs. Benign prostatic hypertrophy,
a common problem in older men, may be aggravated by
androgenic effects that may enlarge the prostate further,
leading to urinary difficulties and increased risk of prostate
cancer.
Many older adults have hepatic dysfunction and
these drugs can be hepatotoxic. Older people should be
monitored very carefully and dose should be reduced.
If signs of liver failure or hepatitis occur, the drug should
be stopped immediately.
TABLE 41.1
DRUGS IN FOCUS Androgens
Drug name
Dosage/route
Usual indications
danazol (Azol)
200–800 mg daily in 2–4 divided doses
Blockade of follicle-stimulating hormone
and luteinising hormone release
in women to prevent ovulation for
treatment of endometriosis; prevention
of hereditary angio-oedema
mesterolone (Proviron)
25–50 mg PO b.d.
Replacement therapy in male
hypogonadism
testosterone (Andriol,
Andro-Feme,
Reandron)
50–400 mg IM every 2–4 weeks, dose
varies with preparation; some long-acting
depository forms are available; dermatological
patch 4–6 mg/day, replace patch daily
Replacement therapy in hypogonadism;
treatment of delayed puberty in
males and certain breast cancers in
postmenopausal women; prevention of
postpartum breast engorgement
