McKenna's Pharmacology for Nursing, 2e

629

C H A P T E R 4 1 Drugs affecting the male reproductive system

Drug therapy across the lifespan

BOX 41.1

Drugs affecting the male reproductive system

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). 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.

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 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

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

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

testosterone (Andriol, Andro-Feme,

Reandron)