Danazol is a synthetic steroid derived from ethisterone, possessing potent androgenic, anti-estrogenic, and mild progestogenic properties. It is primarily indicated for the treatment of endometriosis, fibrocystic breast disease, and hereditary angioedema. By suppressing pituitary-ovarian axis function, it induces a pseudo-menopausal state, reducing estrogen levels and mitigating symptoms associated with estrogen-dependent conditions. Its immunomodulatory effects also make it valuable in managing certain hematologic and autoimmune disorders.

Features

• Synthetic androgen with significant hypothalamic-pituitary suppression
• Available in 50 mg, 100 mg, and 200 mg capsules
• Oral administration with high lipid solubility
• Half-life of approximately 4–5 hours
• Metabolized extensively in the liver
• Excreted primarily in urine and feces

Benefits

• Effectively reduces pelvic pain and dysmenorrhea in endometriosis
• Decreases frequency and severity of hereditary angioedema attacks
• Promotes regression of fibrocystic breast disease
• May elevate platelet counts in immune thrombocytopenic purpura
• Provides an alternative to surgical intervention for certain conditions
• Allows for cyclic or continuous dosing regimens based on indication

Common use

Danazol is most frequently prescribed for symptomatic endometriosis when conventional analgesics and hormonal treatments prove inadequate. It is also standard therapy for prophylaxis against attacks of hereditary angioedema (types I and II). Off-label uses include management of autoimmune thrombocytopenia, precocious puberty, gynecomastia, and menorrhagia. Its use in benign breast disorders has declined with the availability of selective estrogen receptor modulators.

Dosage and direction

For endometriosis: 400–800 mg daily in two divided doses, beginning during menstruation. Treatment typically continues for 3–6 months but may extend to 9 months if well-tolerated and effective.

For hereditary angioedema: Initial dose of 200 mg two or three times daily; may reduce by 50% at 1–3 month intervals until minimum effective dose is established.

For fibrocystic breast disease: 100–400 mg daily in two divided doses.

Administration with food may minimize gastrointestinal upset. Regular monitoring of liver function, lipids, and hematologic parameters is recommended during therapy.

Precautions

Liver function tests should be performed before initiation and periodically during treatment. Monitor for signs of virilization (acne, hirsutism, clitoromegaly, voice changes). Use with caution in patients with cardiac, renal, or hepatic impairment. May cause fluid retention; caution in patients with hypertension, heart failure, or migraine. Androgenic effects may be irreversible in some cases. Discontinue if signs of benign intracranial hypertension occur.

Contraindications

Pregnancy (Category X) and breastfeeding. Undiagnosed abnormal genital bleeding. Severe hepatic, renal, or cardiac dysfunction. History of thromboembolic disorders. Androgen-dependent tumors. Porphyria. Known hypersensitivity to danazol or any component of the formulation.

Possible side effect

Common: Weight gain, acne, oily skin, hirsutism, deepening voice, hot flashes, sweating, menstrual irregularities, nervousness, emotional lability.

Less common: Hepatic dysfunction, jaundice, pancreatitis, benign intracranial hypertension, glucose intolerance, edema, hypertension, muscle cramps, carpal tunnel syndrome.

Rare: Thrombocytopenia, leukopenia, eosinophilia, allergic reactions, anaphylaxis, peliosis hepatis, hepatic tumors.

Drug interaction

Potentiates action of warfarin (monitor INR closely). May increase cyclosporine, tacrolimus, and carbamazepine levels. Concomitant use with statins may increase risk of rhabdomyolysis. Oral contraceptives may diminish danazol effectiveness. Corticosteroids may have enhanced effect. May alter thyroid function test results without affecting thyroid status.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next dose. Do not double doses. Maintain regular dosing schedule to ensure consistent hormonal suppression. For hereditary angioedema prophylaxis, missed doses may increase breakthrough attack risk.

Overdose

Symptoms may include nausea, vomiting, dizziness, and headache. There is no specific antidote. Treatment is supportive and symptomatic. Gastric lavage may be considered if ingestion was recent. Monitor vital signs and provide appropriate medical care. Dialysis is unlikely to be effective due to high protein binding.

Storage

Store at controlled room temperature (20–25°C or 68–77°F). Protect from light and moisture. Keep container tightly closed. Do not freeze. Keep out of reach of children and pets. Do not use after expiration date printed on packaging.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for diagnosis and treatment decisions. Individual response to danazol may vary. Proper diagnosis and monitoring are essential for safe and effective use. Do not initiate or discontinue therapy without medical supervision.

Reviews

Clinical studies demonstrate danazol’s efficacy in reducing endometriosis-associated pain in 80–90% of patients, with symptom recurrence in approximately 30% within two years post-treatment. For hereditary angioedema prophylaxis, danazol reduces attack frequency by 70–90% in responsive patients. Patient satisfaction varies considerably due to androgenic side effects, with approximately 60% of women reporting acceptable tolerability for intermediate-term treatment. Many experts consider danazol a second-line option due to its side effect profile, reserving it for cases where newer agents are ineffective or unavailable.