Danazol for Endometriosis

INDICATIONS AND USAGE Endometriosis. Danazol capsules are indicated for the treatment of endometriosis amenable to hormonal management. Hereditary Angioedema. Danazol capsules are indicated for the prevention of attacks of angioedema of all types (cutaneous, abdominal, laryngeal) in males and females.

DOSAGE AND ADMINISTRATION Endometriosis. In moderate to severe disease, or in patients infertile due to endometriosis, a starting dose of 800 mg given in two divided doses is recommended. Amenorrhea and rapid response to painful symptoms is best achieved at this dosage level. Gradual downward titration to a dose sufficient to maintain amenorrhea may be considered depending upon patient response. For mild cases, an initial daily dose of 200 mg to 400 mg given in two divided doses is recommended and may be adjusted depending on patient response. Therapy should begin during menstruation. Otherwise, appropriate tests should be performed to ensure that the patient is not pregnant while on therapy with danazol capsules (see CONTRAINDICATIONS and WARNINGS ). It is essential that therapy continue uninterrupted for 3 to 6 months but may be extended to 9 months if necessary. After termination of therapy, if symptoms recur, treatment can be reinstituted. Hereditary Angioedema. The dosage requirements for continuous treatment of hereditary angioedema with danazol capsules should be individualized on the basis of the clinical response of the patient. It is recommended that the patient be started on 200 mg, two or three times a day. After a favorable initial response is obtained in terms of prevention of episodes of edematous attacks, the proper continuing dosage should be determined by decreasing the dosage by 50% or less at intervals of one to three months or longer if frequency of attacks prior to treatment dictates. If an attack occurs, the daily dosage may be increased by up to 200 mg. During the dose adjusting phase, close monitoring of the patient's response is indicated, particularly if the patient has a history of airway involvement.

WARNINGS 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 non-hormonal 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 Error! Hyperlink reference not valid.). 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 intraabdominal 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. Patients should be watched closely for signs of androgenic effects some of which may not be reversible even when drug administration is stopped.

Drug Interactions: 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 can cause insulin resistance. Caution should be exercised when used with antidiabetic drugs. Danazol may raise the plasma levels of cyclosporin and tacrolimus, leading to an increase of the renal toxicity of these drugs. Monitoring of systemic concentrations of these drugs and appropriate dose adjustments may be needed when used concomitantly with danazol. Danazol can increase the calcemic response to synthetic vitamin D analogs in primary hypoparathyroidism. The risk of myopathy and rhabdomyolysis is increased by concomitant administration of danazol with statins such as simvastatin, atorvastatin and lovastatin. Caution should be exercised if used concomitantly. Consult the product labeling for statin drugs for specific information on dose restrictions in presence of danazol.

ADVERSE REACTIONS The following events have been reported in association with the use of danazol capsules: Androgen like effects include weight gain, acne and seborrhea. Mild hirsutism, edema, hair loss, voice change, which may take the form of hoarseness, sore throat or of instability or deepening of pitch, may occur and may persist after cessation of therapy. Hypertrophy of the clitoris is rare. Other possible endocrine effects are menstrual disturbances including spotting, alteration of the timing of the cycle and amenorrhea. Although cyclical bleeding and ovulation usually return within 60-90 days after discontinuation of therapy with danazol capsules, persistent amenorrhea has occasionally been reported. Flushing, sweating, vaginal dryness and irritation and reduction in breast size, may reflect lowering of estrogen. Nervousness and emotional lability have been reported. In the male a modest reduction in spermatogenesis may be evident during treatment. Abnormalities in semen volume, viscosity, sperm count, and motility may occur in patients receiving long-term therapy. Hepatic dysfunction, as evidenced by reversible elevated serum enzymes and/or jaundice, has been reported in patients receiving a daily dosage of danazol capsules of 400 mg or more. It is recommended that patients receiving danazol capsules be monitored for hepatic dysfunction by laboratory tests and clinical observation. Serious hepatic toxicity including cholestatic jaundice, peliosis hepatis, hepatic adenoma, hepatocellular injury, hepatocellular jaundice and hepatic failure have been reported (see WARNINGS and PRECAUTIONS ). Abnormalities in laboratory tests may occur during therapy with danazol capsules including CPK, glucose tolerance, glucagon, thyroid binding globulin, sex hormone binding globulin, other plasma proteins, lipids and lipoproteins. The following reactions have been reported, a causal relationship to the administration of danazol capsules has neither been confirmed nor refuted; allergic: urticaria, pruritus and rarely, nasal congestion; CNS effects: headache, nervousness and emotional lability, dizziness and fainting, depression, fatigue, sleep disorders, tremor, paresthesias, weakness, visual disturbances, and rarely, benign intracranial hypertension, anxiety, changes in appetite, chills, and rarely convulsions, Guillain-Barre syndrome; gastrointestinal: gastroenteritis, nausea, vomiting, constipation, and rarely, pancreatitis and splenic peliosis; musculoskeletal: muscle cramps or spasms, or pains, joint pain, joint lockup, joint swelling, pain in back, neck, or extremities, and rarely, carpal tunnel syndrome which may be secondary to fluid retention; genitourinary: hematuria, prolonged posttherapy amenorrhea; hematologic: an increase in red cell and platelet count. Reversible erythrocytosis, leukocytosis or polycythemia may be provoked. Eosinophilia, leukopenia and thrombocytopenia have also been noted. Skin: rashes (maculopapular, vesicular, papular, purpuric, petechial), and rarely, sun sensitivity, Stevens-Johnson syndrome and erythema multiforme; other: increased insulin requirements in diabetic patients, change in libido, myocardial infarction, palpitation, tachycardia, elevation in blood pressure, interstitial pneumonitis, and rarely, cataracts, bleeding gums, fever, pelvic pain, nipple discharge. Malignant liver tumors have been reported in rare instances, after long-term use.