Skip to Content

Fluoxymesterone

Medically reviewed by Drugs.com. Last updated on Sep 30, 2020.

Pronunciation

(floo oks i MES te rone)

Index Terms

  • Androxy
  • Halotestin

Dosage Forms

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

Tablet, Oral:

Androxy: 10 mg [DSC] [contains fd&c blue #1 aluminum lake, fd&c yellow #10 aluminum lake, fd&c yellow #6 aluminum lake]

Brand Names: U.S.

  • Androxy [DSC]

Pharmacologic Category

  • Androgen

Pharmacology

Synthetic derivative of testosterone; responsible for the normal growth and development of male sex hormones, male sex organs, and maintenance of secondary sex characteristics; large doses suppress endogenous testosterone release

Absorption

Rapid

Metabolism

Hepatic; enterohepatic recirculation

Excretion

Urine (90%); feces (6%)

Half-Life Elimination

10 hours (range: 10-100 minutes)

Protein Binding

98%

Use: Labeled Indications

Breast cancer, metastatic (females): Salvage treatment of inoperable metastatic breast cancer in postmenopausal females.

Delayed puberty (males): Replacement therapy in the treatment of delayed male puberty.

Contraindications

Males with carcinoma of the breast or the prostate (known or suspected); women who are or may become pregnant

Dosing: Adult

Note: Androxy has been discontinued in the Unites States for >1 year.

Breast cancer, metastatic (females): Oral: Manufacturer labeling: 10 to 40 mg daily in divided doses for ≥3 months.

Delayed puberty (males): Oral: 2.5 to 20 mg daily for 4 to 6 months.

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Androxy has been discontinued in the US for more than 1 year.

Note: Dosage and duration of therapy depend upon age, sex, diagnosis, patient’s response to therapy, and appearance of adverse effects.

Delayed puberty: Adolescent Males: Typically not recommended for use before 14 years of age (Palmert 2012): Oral: Usual range: 2.5 mg to 10 mg daily, dose may be administered once daily or divided; reported range: 2.5 to 20 mg; most experts recommend a daily a dose of 2.5 mg for 6 to 60 months dependent upon clinical response (Melmed 2011; Strickland 1993); with testosterone therapy, response may be evaluated every 3 to 6 months and dose titrated as appropriate (Palmert 2012)

Male hypogonadism: Children ≥12 years and Adolescents (Han 2010; Young 2012): Oral: 2.5 to 20 mg daily; dose may be administered once daily or in divided doses for 4 to 6 months; some experts suggest beginning testosterone therapy with low doses and titrating gradually to prevent rapid over-virilization (Young 2012)

Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.

Dosing adjustment for toxicity: Children ≥12 years and Adolescents:

Edema: All patients: If therapy is discontinued due to edema, may reinitiate (if indicated) at a reduced dosage.

Hypogonadism: In adult males, the following have been suggested: Hematocrit (HCT) >50%: Use is not recommended; if HCT >54% during therapy, discontinue until HCT falls to a safe level, assess for hypoxia and sleep apnea; if reinitiating therapy, reduce the dose (Bhasin 2010)

Dosing: Adjustment for Toxicity

Edema: If therapy is discontinued due to edema, may reinitiate (if indicated) at a reduced dosage.

Hypercalcemia during therapy for metastatic breast cancer (females): Discontinue use.

Administration

Males: May be administered in single or divided doses. Females: Administer in divided doses.

Storage

Store between 15°C to 30°C (59°F to 86°F); protect from light.

Drug Interactions

Agents with Blood Glucose Lowering Effects: Androgens may enhance the hypoglycemic effect of Agents with Blood Glucose Lowering Effects. Monitor therapy

Ajmaline: Androgens may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy

C1 inhibitors: Androgens may enhance the thrombogenic effect of C1 inhibitors. Monitor therapy

Corticosteroids (Systemic): May enhance the fluid-retaining effect of Androgens. Monitor therapy

CycloSPORINE (Systemic): Androgens may enhance the hepatotoxic effect of CycloSPORINE (Systemic). Androgens may increase the serum concentration of CycloSPORINE (Systemic). Management: Consider avoiding concomitant use of androgens and cyclosporine. If concomitant use is unavoidable, monitor serum cyclosporine concentrations and for signs and symptoms of hepatotoxicity. Cyclosporine dose reductions may be required. Consider therapy modification

Vitamin K Antagonists (eg, warfarin): Androgens may enhance the anticoagulant effect of Vitamin K Antagonists. Management: Monitor for increased effects of vitamin K antagonists if an androgen is initiated/dose increased, or decreased effects if androgen is discontinued/dose decreased. Significant reductions in vitamin K antagonist dose are likely required. Consider therapy modification

Test Interactions

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

Adverse Reactions

Frequency not defined.

Cardiovascular: Edema

Central nervous system: Anxiety, depression, headache, paresthesia

Dermatologic: Acne vulgaris, androgenetic alopecia

Endocrine & metabolic: Change in libido (decreased libido or increased libido), electrolyte disturbance (calcium, chloride, inorganic phosphate, potassium, and sodium retention), fluid retention, gynecomastia (males), hirsutism, hypercholesterolemia, menstrual disease (females; including amenorrhea)

Gastrointestinal: Gastrointestinal irritation, nausea, vomiting

Genitourinary: Benign prostatic hypertrophy (males), oligospermia (males; at higher doses), priapism (males), testicular atrophy (males), virilization (females; including clitoromegaly, deepening of the voice in females)

Hematologic & oncologic: Clotting factors suppression, polycythemia, prostate carcinoma (males)

Hepatic: Abnormal hepatic function tests, cholestatic jaundice, hepatic insufficiency

Hypersensitivity: Anaphylactoid reaction (non-immunologic anaphylaxis), hypersensitivity reaction

<1%, postmarketing, and/or case reports: Hepatic coma, hepatocellular neoplasm, hepatotoxicity (idiosyncratic; Chalasani 2014), peliosis hepatitis

Warnings/Precautions

Concerns related to adverse effects:

• Cardiovascular events: Available studies are inconclusive regarding the risk of developing major adverse cardiovascular events such as nonfatal myocardial infarction, stroke, or cardiovascular death following testosterone use; most data are specific to men who were prescribed testosterone therapy (Basaria 2010; Corona 2014; Finkle 2014; Morgentaler 2015; Vigen 2013). Evaluate patients for cardiovascular risk factors prior to initiating therapy and monitor closely during therapy for cardiovascular events.

• Hepatic effects: Prolonged use of high doses of oral androgens has been associated with serious hepatic effects (eg, peliosis hepatis, hepatic neoplasms, cholestatic hepatitis, jaundice). Discontinue use in patients with cholestatic hepatitis with jaundice or abnormal LFTs.

• Polycythemia: May increase hematocrit requiring dose adjustment or discontinuation. Withhold initial treatment in patients with hematocrit >48% or >50% if living at higher altitudes. Discontinue therapy if hematocrit exceeds 54% (Endocrine Society [Bhasin 2018]).

• Priapism: Priapism or excessive sexual stimulation may occur.

• Venous thromboembolism: Venous thromboembolic events, including deep vein thrombosis (DVT) and pulmonary embolism (PE), have been reported with testosterone products (FDA Drug Safety Communication 2014). Evaluate patients with symptoms of pain, edema, warmth, and erythema in the lower extremity for DVT and those with acute shortness of breath for PE. Discontinue therapy if a venous thromboembolism is suspected.

Disease-related concerns:

• Benign prostatic hyperplasia: Androgens may worsen benign prostatic hyperplasia (BPH); do not use in patients with severe lower urinary tract symptoms (American Urological Association [AUA]/International Prostate Symptom Score [IPSS] >19) (Endocrine Society [Bhasin 2018]). Discontinue therapy if urethral obstruction develops in patients with BPH (use lower dose if restarted).

• Carbohydrate intolerance: May have adverse effects on glucose tolerance; use caution in patients with diabetes.

• Diseases exacerbated by fluid retention: Use with caution in patients with diseases that may be exacerbated by fluid retention, including cardiac impairment; may cause fluid retention.

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

• Hypercalcemia: Use with caution in patients with breast cancer or immobilization; may cause hypercalcemia by stimulating osteolysis. Discontinue use if hypercalcemia occurs; may indicate bony metastasis.

• Prostate cancer: May increase the risk of prostate cancer. Withhold therapy pending urological evaluation in patients with palpable prostate nodule or induration, PSA >4 ng/mL, or PSA >3 ng/mL in men at high risk of prostate cancer (Endocrine Society [Bhasin 2018]).

• Renal impairment: Use with caution in renal impairment; not recommended for androgen replacement in hypogonadal males with severe lower urinary tract symptoms (eg, IPSS >19) (Endocrine Society [Bhasin 2018]).

• Sleep apnea: May potentiate sleep apnea; withhold initial treatment in patients with untreated obstructive sleep apnea (Endocrine Society [Bhasin 2018]).

Special populations:

• Pediatric: 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.

• Women: During treatment for metastatic breast cancer, women should be monitored for signs of virilization (eg, deepening of voice, hirsutism, acne, clitoromegaly, menstrual irregularities); discontinue use with evidence of mild virilization to prevent irreversible symptoms.

Other warnings/precautions:

• Abuse/misuse/diversion: Anabolic steroids may be abused, typically at doses higher than recommended and in combination with other anabolic androgenic steroids; abuse may be associated with serious cardiovascular and psychiatric adverse reactions. Inform patients of the serious adverse reactions associated with abuse of testosterone and anabolic androgenic steroids; if abuse is suspected, check serum testosterone levels (testosterone levels may be in the normal or subnormal range in men abusing synthetic testosterone derivatives). Consider the possibility of abuse in suspected patients who present with serious cardiovascular or psychiatric adverse events.

• Dependence: Drug dependence in individuals using approved doses of testosterone for approved indications has not been documented; however, dependence may occur when used outside of approved dosage/indications.

Monitoring Parameters

LFTs, lipid panel, hemoglobin and hematocrit (at 3 to 6 months then annually). Monitor urine and serum calcium and signs of virilization in women treated for breast cancer. Serum glucose (may be decreased by testosterone, monitor patients with diabetes). Monitor for cardiovascular events closely during therapy. Monitor PSA if clinically indicated. In prepubertal patients, perform radiologic examination of wrist and hand every 6 months.

Reproductive Considerations

Use is contraindicated in women who may become pregnant.

Pregnancy Risk Factor

X

Pregnancy Considerations

Use is contraindicated in women who are pregnant. May cause androgenic effects to the female fetus; clitoral hypertrophy, labial fusion, urogenital sinus defect, vaginal atresia, and ambiguous genitalia have been reported.

Patient Education

What is this drug used for?

• It is used to treat low testosterone levels.

• It is used for delayed puberty in certain male children.

• It is used to treat breast cancer in women.

• It may be given to you for other reasons. Talk with the doctor.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Enlarged breasts (males)

• Acne

• Decreased sex drive

• Anxiety

• Headache

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• High calcium like weakness, confusion, feeling tired, headache, nausea and vomiting, constipation, or bone pain.

• Liver problems like dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes.

• Virilization like in females a deep voice, facial hair, pimples, or period changes.

• Shortness of breath

• Excessive weight gain

• Swelling of arms or legs

• Skin discoloration

• Depression

• Burning or numbness feeling

• Nausea

• Vomiting

• Erection that lasts more than 4 hours

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.