Danazol

Danazol is a synthetic androgen derived from ethisterone, primarily indicated for the treatment of endometriosis and hereditary angioedema (HAE). It functions by suppressing pituitary-ovarian axis activity, leading to reduced estrogen production and amelioration of estrogen-dependent conditions. Its androgenic and anti-estrogenic properties make it a cornerstone in managing select gynecological and immunological disorders where hormonal modulation is therapeutic.

Features

• Synthetic steroid with attenuated androgenic properties
• Oral administration with high bioavailability
• Suppresses gonadotropin secretion (LH and FSH)
• Increases serum levels of C1 esterase inhibitor in HAE
• Reduces estrogen production by inhibiting ovarian steroidogenesis
• Available in 50 mg, 100 mg, and 200 mg capsules

Benefits

• Provides significant relief from pelvic pain associated with endometriosis
• Reduces frequency and severity of hereditary angioedema attacks
• Helps prevent disease progression in benign breast disorders
• Offers an alternative to surgical intervention in select cases
• May improve hematologic parameters in certain types of anemia
• Allows for long-term management with appropriate monitoring

Common use

Danazol is most frequently prescribed for the treatment of endometriosis, particularly in cases where pain is refractory to NSAIDs or combination oral contraceptives. It is also a first-line therapy for prophylaxis against attacks of hereditary angioedema. Off-label uses include management of fibrocystic breast disease, idiopathic thrombocytopenic purpura (ITP), and autoimmune hemolytic anemia. Its use is generally reserved for patients who have not responded to conventional therapies due to its androgenic side effect profile.

Dosage and direction

For endometriosis: The initial dosage is 200–400 mg twice daily, titrated to the lowest effective dose based on symptom response. Treatment typically begins during menstruation and continues for 3–6 months, but may extend to 9 months in severe cases.

For hereditary angioedema: Starting dose is 200 mg two to three times daily, with subsequent adjustments made to maintain clinical remission. Maintenance doses often range from 200 mg daily to 400 mg daily.

Administration should be with food to minimize gastrointestinal upset. Dosage must be individualized based on therapeutic response and side effects.

Precautions

Liver function tests should be monitored regularly due to potential hepatotoxicity. Lipid profiles may be adversely affected; periodic assessment is recommended. Patients should be advised regarding potential androgenic effects such as acne, hirsutism, and voice changes. Use with caution in patients with cardiac, renal, or hepatic impairment. Danazol may cause fluid retention; caution is advised in patients with hypertension, heart failure, or migraine. Embryo-fetal toxicity is possible; pregnancy must be excluded before initiation.

Contraindications

Danazol is contraindicated in patients with:

• Pregnancy or breastfeeding
• Undiagnosed abnormal genital bleeding
• Severe hepatic, renal, or cardiac dysfunction
• History of thromboembolic disorders
• Androgen-dependent tumors such as prostate or breast cancer
• Porphyria

Possible side effect

Common adverse reactions include:

• Weight gain (20–30% of patients)
• Acne and oily skin (15–25%)
• Hirsutism (10–20%)
• Edema (5–15%)
• Hot flashes and menstrual irregularities
• Voice deepening (may be irreversible)
• Headache and dizziness

Serious but rare side effects include:

• Hepatotoxicity (elevated transaminases, jaundice)
• Thromboembolic events
• Benign intracranial hypertension
• Peliosis hepatis
• Leukopenia or thrombocytopenia

Drug interaction

Danazol inhibits cytochrome P450 3A4 and may increase levels of:

• Carbamazepine (risk of toxicity)
• Cyclosporine (nephrotoxicity)
• Statins (increased risk of myopathy)
• Warfarin (enhanced anticoagulant effect)

Concomitant use with insulin or oral hypoglycemics may alter glucose control. Danazol may reduce the efficacy of hormone replacement therapy or oral contraceptives.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose. Do not double the dose to make up for a missed one. Consistent timing is important to maintain stable drug levels, particularly for HAE prophylaxis.

Overdose

Symptoms of overdose may include exaggerated androgenic effects, nausea, vomiting, and dizziness. 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 management based on clinical presentation.

Storage

Store at room temperature (15–30°C/59–86°F) in a tightly closed container. Protect from light and moisture. Keep out of reach of children and pets. Do not use after the expiration date printed on the 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 recommendations. Dosage and indications may vary based on individual patient factors and current medical guidelines. The prescriber should be familiar with the complete prescribing information before initiating therapy.

Reviews

Clinical studies have demonstrated danazol’s efficacy in reducing endometriosis-associated pain in approximately 80–90% of patients during treatment, though recurrence rates post-therapy remain significant. In hereditary angioedema, danazol has been shown to reduce attack frequency by 70–90% in responsive patients. Patient satisfaction varies considerably due to side effects, with many reporting improved quality of life despite androgenic adverse reactions. Long-term follow-up studies indicate that benefits generally outweigh risks when used appropriately in indicated populations with careful monitoring.