Use of danazol in pregnancy is contraindicated. A sensitive test (e.g., beta subunit test if available) capable of determining early pregnancy is recommended immediately prior to start of therapy. Additionally a nonhormonal method of contraception should be used during therapy. If a patient becomes pregnant while taking danazol, administration of the drug should be discontinued and the patient should be apprised of the potential risk to the fetus. Exposure to danazol in utero may result in androgenic effects on the female fetus; reports of clitoral hypertrophy, labial fusion, urogenital sinus defect, vaginal atresia, and ambiguous genitalia have been received. (See PRECAUTIONS: Pregnancy, Teratogenic Effects.)
Thromboembolism, thrombotic and thrombophlebitic events including sagittal sinus thrombosis and life-threatening or fatal strokes have been reported.
Experience with long-term therapy with danazol is limited. Peliosis hepatis and benign hepatic adenoma have been observed with long-term use. Peliosis hepatis and hepatic adenoma may be silent until complicated by acute, potentially life-threatening intra-abdominal hemorrhage. The physician therefore should be alert to this possibility. Attempts should be made to determine the lowest dose that will provide adequate protection. If the drug was begun at a time of exacerbation of hereditary angioneurotic edema due to trauma, stress or other cause, periodic attempts to decrease or withdraw therapy should be considered.
Danazol has been associated with several cases of benign intracranial hypertension also known as pseudotumor cerebri. Early signs and symptoms of benign intracranial hypertension include papilledema, headache, nausea and vomiting, and visual disturbances. Patients with these symptoms should be screened for papilledema and, if present, the patients should be advised to discontinue danazol immediately and be referred to a neurologist for further diagnosis and care.
A temporary alteration of lipoproteins in the form of decreased high density lipoproteins and possibly increased low density lipoproteins has been reported during danazol therapy. These alterations may be marked, and prescribers should consider the potential impact on the risk of atherosclerosis and coronary artery disease in accordance with the potential benefit of the therapy to the patient.
Before initiating therapy of fibrocystic breast disease with danazol, carcinoma of the breast should be excluded. However, nodularity, pain, tenderness due to fibrocystic breast disease may prevent recognition of underlying carcinoma before treatment is begun. Therefore, if any nodule persists or enlarges during treatment, carcinoma should be considered and ruled out.
Patients should be watched closely for signs of androgenic effects some of which may not be reversible even when drug administration is stopped.
Because danazol may cause some degree of fluid retention, conditions that might be influenced by this factor, such as epilepsy, migraine, or cardiac or renal dysfunction, require careful observation.
Since hepatic dysfunction manifested by modest increases in serum transaminase levels has been reported in patients treated with danazol, periodic liver function tests should be performed (see WARNINGS and ADVERSE REACTIONS).
Administration of danazol has been reported to cause exacerbation of the manifestations of acute intermittent porphyria. (See CONTRAINDICATIONS.)
Prolongation of prothrombin time occurs in patients stabilized on warfarin. Therapy with danazol may cause an increase in carbamazepine levels in patients taking both drugs.
Danazol treatment may interfere with laboratory determinations of testosterone, androstenedione and dehydroepiandrosterone.
Carcinogenesis, Mutagenesis, Impairment of Fertility:
No valid studies have been performed to assess the carcinogenicity of danazol.
Pregnancy: Teratogenic Effects:
Pregnancy Category X:
Danazol administered orally to pregnant rats from the 6th through the 15th day of gestation at doses up to 250 mg/kg/day (7-15 times the human dose) did not result in drug-induced embryotoxicity or teratogenicity, nor difference in litter size, viability or weight of offspring compared to controls. In rabbits, the administration of danazol on days 6-18 of gestation at doses of 60 mg/kg/day and above (2-4 times the human dose) resulted in inhibition of fetal development.
Safety and effectiveness in pediatric patients have not been established.