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Medication Safety Issues

Sound-alike/look-alike issues:

Testolactone may be confused with testosterone

Pronunciation

(tes toe LAK tone)

U.S. Brand Names

• Teslac® [DSC]

Generic Available

No

Canadian Brand Names

• Teslac®

Pharmacologic Category

• Androgen

Use: Labeled Indications

Palliative treatment of advanced or disseminated breast carcinoma

Restrictions

C-III

Pregnancy Risk Factor

C

Pregnancy Considerations

Teratogenic effects were not observed in animal studies. Testolactone should only be used in postmenopausal women; use during pregnancy is not recommended.

Lactation

Excretion in breast milk unknown/not recommended

Contraindications

Hypersensitivity to testolactone or any component of the formulation; treatment of breast cancer in men

Warnings/Precautions

Disease-related concerns:

• Cardiovascular disease: Use with caution in patients with cardiovascular disease.

• Diabetes: Use with caution in patients with diabetes mellitus; monitor carefully.

• Hepatic impairment: Use with caution in patients with hepatic impairment.

• Porphyria: Use with caution in patients with a history of porphyria.

• Renal impairment: Use with caution in patients with renal impairment.

Special populations:

• Pediatrics: Safety and efficacy have not been established in children.

• Women: For use in postmenopausal women or in premenopausal women without ovarian function only.

Adverse Reactions

Frequency not defined.

Cardiovascular: Blood pressure increased, edema

Central nervous system: Malaise

Dermatologic: Alopecia (rare), maculopapular rash

Endocrine & metabolic: Hypercalcemia

Gastrointestinal: Anorexia, diarrhea, nausea, tongue edema

Neuromuscular & skeletal: Paresthesia, peripheral neuropathy

Miscellaneous: Nail growth disturbance (rare)

Drug Interactions

CycloSPORINE: Androgens may enhance the hepatotoxic effect of CycloSPORINE. Androgens may increase the serum concentration of CycloSPORINE. Risk D: Consider therapy modification

Vitamin K Antagonists (eg, warfarin): Androgens may enhance the anticoagulant effect of Vitamin K Antagonists. Risk D: Consider therapy modification

Mechanism of Action

Testolactone is a synthetic testosterone derivative without significant androgen activity. The drug inhibits steroid aromatase activity, thereby blocking the production of estradiol and estrone from androgen precursors such as testosterone and androstenedione. Unfortunately, the enzymatic block provided by testolactone is transient and is usually limited to a period of 3 months.

Pharmacodynamics/Kinetics

Absorption: Well absorbed

Metabolism: Hepatic (forms metabolites)

Excretion: Urine

Dosage

Adults: Females: Oral: 250 mg 4 times/day for at least 3 months; desired response may take as long as 3 months

Monitoring Parameters

Plasma calcium levels

Test Interactions

Plasma estradiol concentrations by RIA

Patient Education

Take as directed; do not discontinue without consulting prescriber. Effectiveness of therapy may take several months. Maintain adequate hydration (2-3 L/day of fluids) unless instructed to restrict fluid intake, and diet and exercise program recommended by prescriber. You may experience nausea or vomiting (small, frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help). Report fluid retention (swelling of ankles, feet, or hands; respiratory difficulty or sudden weight gain); numbness, tingling, or swelling of fingers, toes, or face; skin rash, redness, or irritation; or other adverse reactions. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to become pregnant. Breast-feeding is not recommended.

Dental Health: Effects on Dental Treatment

Key adverse event(s) related to dental treatment: Tongue edema.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions

No information available to require special precautions

Mental Health: Effects on Mental Status

None reported

Mental Health: Effects on Psychiatric Treatment

None reported

Nursing: Physical Assessment/Monitoring

For use in postmenopausal women or in premenopausal women without ovarian function only. May increase effects of oral anticoagulants. Evaluate effectiveness of therapy, laboratory tests, and adverse reactions. Assess knowledge/teach patient appropriate use, possible side effects/appropriate interventions, and adverse symptoms to report.

Oncology: Emetic Potential

Very low (<10%)

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Tablet:

Teslac®: 50 mg [DSC]

International Brand Names

• Fludestrin (DE)

Lexi-Comp.com

Last full review/revision January 2009