TESTOLACTONE
(tess-toe-lak'tone)
Teslac
Classifications: antineoplastic; hormone; anabolic steroid
Pregnancy Category: C
Controlled Substance: Schedule III

Availability

50 mg tablets

Actions

Chemotherapeutic agent with chemical configuration similar to certain androgens but devoid of androgenic activity (virilization) in therapeutic doses. Exact mechanism of antineoplastic action unknown.

Therapeutic Effects

In breast cancer, effect may result from depression of ovarian function by inhibition of synthesis of pituitary gonadotropin. Indicated by decrease in size of tumor; more than 50% of nonosseous lesions decrease in size even though all bone lesions remain static.

Uses

Adjunctive treatment in palliation of breast carcinoma in postmenopausal women when hormone therapy is indicated. Also effective in women diagnosed before menopause in whom ovarian function has been subsequently terminated.

Contraindications

Premenopausal women; breast cancer in males. Pregnancy (category C), lactation.

Cautious Use

Hypercalcemia; cardiorenal disease.

Route & Dosage

Adjunctive Therapy for Breast Cancer
Adult: PO 250 mg q.i.d.

Administration

Oral

Note: If anticoagulants are concurrently ordered, dose is usually reduced when testolactone is initiated.
Store at 15°–30° C (59°–86° F) unless otherwise directed. Protect from freezing.

Adverse Effects (1%)

CNS: Paresthesias. Endocrine: Deepening of the voice, acne, facial hair growth, clitoral enlargement. GI: Glossitis, anorexia; nausea, vomiting. CV: Hypertension, edema in extremities.

Diagnostic Test Interference

Urinary 17-OHCS determinations may be elevated.

Interactions

Drug: May enhance hypoprothrombinemic effects of oral anticoagulants.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Metabolism: Metabolized in liver. Elimination: Excreted in urine.

Nursing Implications

Assessment & Drug Effects

Monitor therapeutic effectiveness. Clinical response usually occurs in 6–12 wk.
Lab tests: Check plasma calcium levels periodically (normal serum calcium: 8.5–10.6 mg/dL).
Monitor PT and INR carefully with concurrent anticoagulant therapy.
Report S&S that suggest impending hypercalcemia (see Appendix F).
Monitor I&O ratio and pattern.
Encourage patient mobility if feasible; if not, assist with passive exercises.

Patient & Family Education

Drug treatment is usually continued for a minimum of 3 mo to evaluate response (unless there is active progression of the disease).
Be aware that hypercalcemia represents active remission of bone metastasis; if it occurs, appropriate therapy is instituted.
Do not breast feed while taking this drug.

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