General Information

Danazol is a synthetic androgen with antigonadotropic properties, used primarily for the treatment of endometriosis and fibrocystic breast disease. It works by inhibiting the release of gonadotropins from the pituitary gland, thus reducing ovarian activity and estrogen production.

Mechanism of Action

Danazol exerts its effects through its interaction with androgen receptors, leading to decreased production of gonadotropins (LH and FSH) from the anterior pituitary. This suppression results in reduced ovarian hormone synthesis, mitigating symptoms related to endometriosis and fibrocystic breast disease.

Pharmacokinetics

Danazol is well-absorbed orally, with peak plasma concentrations occurring approximately 2 to 8 hours post-administration. It has a half-life of 4.5 to 5.5 hours. Danazol is metabolized in the liver and primarily excreted as metabolites in the urine, with a minor percentage excreted in feces.

Indications

Indicated for the treatment of moderate to severe endometriosis and fibrocystic breast disease. Additionally, Danazol may be used in patients with hereditary angioedema to prevent and treat attacks of angioedema.

Dosage Information

For endometriosis, the typical starting dose is 200–400 mg daily in divided doses. For fibrocystic breast disease, the usual dosage ranges from 100–400 mg daily. For hereditary angioedema, dosing must be individualized based on clinical response, typically between 200–600 mg daily.

Administration Guidelines

Danazol should be taken orally with food to enhance its absorption. The dosage may be adjusted based on therapeutic response and tolerability, with routine monitoring of patient response to therapy.

Contraindications

Danazol is contraindicated in patients with known hypersensitivity to the drug, active or history of thrombosis or thromboembolic disease, severe hepatic impairment, undiagnosed vaginal bleeding, pregnancy, and breastfeeding. It is also contraindicated in patients with porphyria.

Drug Interactions

Danazol may interact with warfarin, increasing its anticoagulant effect. Co-administration with statins may increase the risk of myopathy. Danazol can enhance the effects of cyclosporine and tacrolimus, requiring dose adjustments. Concurrent administration with carbamazepine and rifampin may reduce the efficacy of Danazol.

Adverse Effects

Common adverse effects include weight gain, acne, seborrhea, hirsutism, and voice changes. Serious side effects can include thromboembolic events, liver function abnormalities, and intracranial hypertension. Patients should be monitored for signs of adverse reactions throughout treatment.

Monitoring Requirements

Regular liver function tests should be conducted to detect hepatotoxicity. Lipid profiles should be monitored, as Danazol can affect cholesterol and triglyceride levels. Periodic assessment of hematologic parameters is recommended, especially in long-term therapy cases.

Special Populations

In the elderly, dose adjustments may be required due to age-related hepatic and renal function impairments. Pediatric use is not recommended due to insufficient safety and efficacy data. In patients with renal impairment, caution and possible dosage adjustments are necessary.

Storage Conditions

Store Danazol at room temperature, between 20°C and 25°C (68°F to 77°F). Keep the medication in a tightly sealed container, away from excessive heat, moisture, and light. Ensure that it is kept out of reach of children.

Missed Dose Instructions

If a dose is missed, the patient should take it as soon as they remember. If it is near the time of the next dose, they should skip the missed dose and resume their usual dosing schedule. Do not double the dose to catch up.

Disposal Guidelines

Unneeded or expired Danazol should be disposed of properly. Do not dispose of medications in wastewater or household trash. Use drug take-back programs if available, or consult a pharmacist for appropriate disposal methods.

Overdose Management

In case of overdose, supportive care and symptomatic treatment should be provided. There is no specific antidote for Danazol overdose. Consideration should be given to the patient’s clinical status and the extent of overdose toxicity.