Fluoxymesterone

Pronunciation

(floo oks i MES te rone)

U.S. Brand Names

Halotestin®

Generic Available

Yes

Canadian Brand Names

Halotestin®

Use

Replacement of endogenous testicular hormone; in females, used as palliative treatment of breast cancer

Use - Unlabeled/Investigational

Stimulation of erythropoiesis, angioneurotic edema

Restrictions

C-III

Pregnancy Risk Factor

X

Lactation

Excretion in breast milk unknown/contraindicated

Contraindications

Hypersensitivity to fluoxymesterone or any component of the formulation; serious cardiac disease, liver or kidney disease; pregnancy

Warnings/Precautions

May accelerate bone maturation without producing compensatory gain in linear growth in children; in prepubertal children perform radiographic examination of the hand and wrist every 6 months to determine the rate of bone maturation and to assess the effect of treatment on the epiphyseal centers

Adverse Reactions

>10%:

Male: Priapism

Female: Menstrual problems (amenorrhea), virilism, breast soreness

Cardiovascular: Edema

Dermatologic: Acne

1% to 10%:

Male: Prostatic carcinoma, hirsutism (increase in pubic hair growth), impotence, testicular atrophy

Cardiovascular: Edema

Gastrointestinal: GI irritation, nausea, vomiting

Genitourinary: Prostatic hyperplasia

Hepatic: Hepatic dysfunction

<1%:

Male: Gynecomastia

Female: Amenorrhea

Hypercalcemia, leukopenia, polycythemia, hepatic necrosis, cholestatic hepatitis, hypersensitivity reactions

Overdosage/Toxicology

Symptoms of overdose include water retention. Abnormal liver function tests have been observed.

Drug Interactions

Decreased effect:

Fluphenazine effectiveness with anticholinergics

Barbiturate levels and decreased fluphenazine effectiveness when given together

Increased toxicity:

Anticoagulants: Fluoxymesterone may suppress clotting factors II, V, VII, and X; therefore, bleeding may occur in patients on anticoagulant therapy

Cyclosporine: May elevate cyclosporine serum levels

Insulin: May enhance hypoglycemic effect of insulin therapy

May decrease blood glucose concentrations and insulin requirements in patients with diabetes

With ethanol, effects of both drugs may increase

EPSEs and other CNS effects may increase when coadministered with lithium

May potentiate the effects of narcotics including respiratory depression

Stability

Protect from light

Mechanism of Action

Synthetic androgenic anabolic hormone responsible for the normal growth and development of male sex hormones and development of male sex organs and maintenance of secondary sex characteristics; synthetic testosterone derivative with significant androgen activity; stimulates RNA polymerase activity resulting in an increase in protein production; increases bone development; halogenated derivative of testosterone with up to 5 times the activity of methyltestosterone

Pharmacodynamics/Kinetics

Absorption: Rapid

Protein binding: 98%

Metabolism: Hepatic; enterohepatic recirculation

Half-life elimination: 10-100 minutes

Excretion: Urine (90%)

Dosage

Adults: Oral:

Male:

Hypogonadism: 5-20 mg/day

Delayed puberty: 2.5-20 mg/day for 4-6 months

Female: Inoperable breast carcinoma: 10-40 mg/day in divided doses for 1-3 months

Monitoring Parameters

In prepubertal children, perform radiographic examination of the hand and wrist every 6 months

Test Interactions

Decreased levels of thyroxine-binding globulin; decreased total T4 serum levels; increased resin uptake of T3 and T4

Patient Education

Inform prescriber of all prescriptions, OTC medications, or herbal products you are taking, and any allergies you have. Do not take any new medication during therapy unless approved by prescriber. Take as directed; do not discontinue without consulting prescriber. If you have diabetes, monitor serum glucose closely and notify prescriber of changes; this medication can alter hypoglycemic requirements. May cause acne, growth of body hair, loss of libido, impotence, or menstrual irregularity (usually reversible); or nausea or vomiting (small, frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help). Report changes in menstrual pattern; deepening of voice or unusual growth of body hair; fluid retention (swelling of ankles, feet, or hands, respiratory difficulty, or sudden weight gain); change in color of urine or stool; yellowing of eyes or skin; unusual bruising or bleeding; or other adverse reactions. Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant and do not get pregnant during or for 1 month following therapy. Consult prescriber for instruction on appropriate barrier contraceptive measures. This drug may cause severe fetal defects. Do not breast-feed.

Nursing Implications

In prepubertal children, perform radiographic examination of the hand and wrist every 6 months

Dental Health: Effects on Dental Treatment

No significant effects or complications reported

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

May cause leukopenia; use caution with clozapine and carbamazepine

Oncology: Emetic Potential

Very low (<10%)

Dosage Forms

[DSC] = Discontinued product

Tablet: 10 mg

Halotestin®: 2 mg, 5 mg, 10 mg [contains tartrazine; 10 mg tablet DSC]

International Brand Names

Halotestin® (AU, CA, HK, HU, TH); Stenox® (MX); Testaflor® (CL)