TESTOSTERONE

TESTOSTERONE (tess-toss'ter-one) Androderm, AndroGel, Striant, Testim TESTOSTERONE CYPIONATE Andro-Cyp, Depo-Testosterone, Depotest TESTOSTERONE ENANTHATE Delatest, Delatestryl, Malogex  Classifications: hormone; androgen/anabolic steroid; antineoplastic; Therapeutic: antineoplastic; anabolic steroid Pregnancy Category: X Controlled Substance: Schedule III

Availability

Testosterone 75 mg implantable pellets; 2.5 mg/24 h, 4 mg/24 h, 5 mg/24 h, 6 mg/24 h, transdermal patch; 1% gel; 2.5 g, 5 g gel packets; 30 mg buccal patch;

Testosterone Cypionate 100 mg/mL, 200 mg/mL injection;

Testosterone Enanthate 100 mg/mL, 200 mg/mL injection

Action

Synthetic steroid compound with both androgenic and anabolic activity (1:1). Controls development and maintenance of secondary sexual characteristics. Androgenic activity: Responsible for the growth spurt of the adolescent and for growth termination by epiphyseal closure. In males and some females, reduces excretion of phosphorus, nitrogen, potassium, sodium, and chloride. Increases erythropoiesis, possibly by stimulating production of renal or extrarenal erythropoietin, and promotes vascularization and darkening of skin. Anabolic activity: Increases protein metabolism and decreases its catabolism. Large doses suppress spermatogenesis, thereby causing testicular atrophy.

Therapeutic Effect

Antagonizes effects of estrogen excess on female breast and endometrium. Responsible for the growth spurt of the adolescent male and onset of puberty.

Uses

Androgen replacement therapy, delayed puberty (male), palliation of female mammary cancer (1–5 y postmenopausal), and to treat postpartum breast engorgement. Available in fixed combination with estrogens in many preparations.

Contraindications

Hypersensitivity or toxic reactions to androgens; serious cardiac, liver, or kidney disease; hypercalcemia; known or suspected prostatic or breast cancer in male; benign prostatic hypertrophy with obstruction; patients easily stimulated sexually; older adults; asthenic males who may react adversely to androgenic overstimulation; conditions aggravated by fluid retention; hypertension; pregnancy (category X), possibility of virilization of external genitalia of female fetus, lactation.

Cautious Use

Cardiac, liver, and kidney disease; prepubertal males; diabetes mellitus; history of MI; CAD; BPH; geriatric patients, acute intermittent porphyria.

Route & Dosage

Male Hypogonadism Adult: IM Cypionate, Enanthate 50–400 mg q2–4wk Topical Start with 6 mg/d system applied daily, if scrotal area inadequate, use 4 mg/d system; Androderm Apply to torso; AndroGel Apply one packet to upper arms, shoulders, or abdomen once daily; Striant Apply one patch to the gum region just above the incisor tooth q12h Delayed Puberty Adult: IM Cypionate, Enanthate 50–200 mg q2–4wk Metastatic Breast Cancer Adult: IM Cypionate, Enanthate 200–400 mg q2–4wk

Administration

Buccal

• Apply buccal patch to gum just above the incisor tooth.

Transdermal

• Apply transdermal system on clean, dry scrotal skin. Dry shave scrotal hair for optimal skin contact. Do not use chemical depilatories. Wear patch for 22–24 h.
• Apply Androderm patches to abdomen, back, thigh, or upper arm. Alternate application site q24h with ≥7 d between same site.
• Store at 15°–30° C (59°–86° F).

Intramuscular

• Give IM injections deep into gluteal musculature.
• Store IM formulations prepared in oil at room temperature. Warming and shaking vial will redisperse precipitated crystals.

Adverse Effects (≥1%)

CNS: Excitation, insomnia. CV: Skin flushing and vascularization. GI: Nausea, vomiting, anorexia, diarrhea, gastric pain, jaundice. Hematologic: Leukopenia. Metabolic: Hypercalcemia, hypercholesterolemia, sodium and water retention (especially in older adults) with edema. Renal: Renal calculi (especially in the immobilized patient), bladder irritability. Urogenital: Increased libido. Skin: Acne, injection site irritation and sloughing. Body as a Whole: Hypersensitivity to testosterone, anaphylactoid reactions (rare). Hematologic: Precipitation of acute intermittent porphyria. Endocrine: Female—suppression of ovulation, lactation, or menstruation; hoarseness or deepening of voice (often irreversible); hirsutism; oily skin; clitoral enlargement; regression of breasts; male-pattern baldness (in disseminated breast cancer); flushing, sweating; vaginitis with pruritus, drying, bleeding; menstrual irregularities. Male—prepubertal-premature epiphyseal closure, phallic enlargement, priapism. Postpubertal—testicular atrophy, decreased ejaculatory volume, azoospermia, oligospermia (after prolonged administration or excessive dosage), impotence, epididymitis, priapism, gynecomastia.

Diagnostic Test Interference

Testosterone alters glucose tolerance tests; decreases thyroxine-binding globulin concentration (resulting in decreased total T₄ serum levels and increased resin of T₃ and T₄ ). Increases creatinine and creatinine excretion (lasting up to 2 wk after therapy is discontinued) and alters response to metyrapone test. It suppresses clotting factors II, V, VII, X and decreases excretion of 17-ketosteroids. May increase or decrease serum cholesterol.

Interactions

Drug: oral anticoagulants may potentiate hypoprothrombinemia. May decrease insulin requirements.

Pharmacokinetics

Absorption: Cypionate and enanthate are slowly absorbed from lipid tissue. Duration: 2–4 wk cypionate and enanthate. Distribution: 98% bound to sex hormone-binding globulin. Metabolism: Primarily in liver. Elimination: 90% in urine, 6% in feces. Half-Life: 10–100 min.

Nursing Implications

Assessment & Drug Effects

• Therapeutic response from testosterone therapy is slow; breast cancer, usually apparent within 3 mo after regimen begins. Terminate therapy if signs of disease progression appear.
• Check I&O and weigh patient daily during dose adjustment period. Weight gain (due to sodium and water retention) suggests need for decreased dosage. When dosage is stabilized, urge patient to check weight at least twice weekly and to report increases, particularly if accompanied by edema in dependent areas. Dose adjustment and diuretic therapy may be started.
• Lab tests: Periodic serum cholesterol, serum electrolytes as well as liver function tests throughout therapy.
• Monitor serum calcium closely. Androgenic therapy is usually terminated if serum calcium rises above 14 mg/dL.
• Report S&S of hypercalcemia (see Appendix F) promptly. The immobilized patient is particularly prone to develop hypercalcemia, which indicates progression of bone metastasis in patients with metastatic breast cancer. Treatment includes withdrawing testosterone and checking calcium, phosphate, and BUN levels daily.
• Instruct diabetic to report sweating, tremor, anxiety, vertigo. Testosterone-induced anabolic action enhances hypoglycemia (hyperinsulinism). Dosage adjustment of antidiabetic agent may be required.
• Observe patients on concomitant anticoagulant treatment for signs of overdosage (e.g., ecchymoses, petechiae). Report promptly to physician; anticoagulant dose may need to be reduced.
• Monitor prepubertal or adolescent males throughout therapy to avoid precocious sexual development and premature epiphyseal closure. Skeletal stimulation may continue 6 mo beyond termination of therapy.

Patient & Family Education

• Review directions for application of transdermal patches.
• Report soreness at injection site, because postinjection furunculosis may be an associated adverse reaction.
• Report priapism (sustained and often painful erections occurring especially in early replacement therapy), reduced ejaculatory volume, and gynecomastia to physician. Symptoms indicate necessity for temporary withdrawal or discontinuation of testosterone therapy.
• Notify physician promptly if pregnancy is suspected or planned. Masculinization of the fetus is most likely to occur if testosterone (androgen) therapy is provided during first trimester of pregnancy.
• Androgens may cause virilism in women at dosage required to treat carcinoma. Report increase in libido (early sign of toxicity), growth of facial hair, deepening of voice, male-pattern baldness. The onset of hoarseness can easily be overlooked unless its significance as an early and possibly irreversible sign of virilism is appreciated. Reevaluation of treatment plan is indicated.

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Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug