Medically reviewed on March 25, 2018
(DA na zole)
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Generic: 50 mg, 100 mg, 200 mg
Suppresses pituitary output of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), resulting in regression and atrophy of normal and ectopic endometrial tissue; decreases rate of growth of abnormal breast tissue; reduces attacks associated with hereditary angioedema by increasing levels of C4 component of complement
Extensively hepatic, primarily to 2-hydroxymethyl danazol and ethisterone
Urine and feces
Onset of Action
Fibrocystic breast disease: Onset of pain/tenderness relief: 1 month (usually significantly relieved at 2 to 3 months); nodule elimination: 4 to 6 months
Immune thrombocytopenia (off-label use): Initial response: 14 to 90 days; Peak response: 28 to 180 days (Neunert 2011)
Time to Peak
Serum: 4 hours (range: 2 to 8 hours)
~10 hours (variable; up to 24 hours following long-term use for endometriosis)
Use: Labeled Indications
Endometriosis: Treatment of endometriosis amenable to hormonal management.
Fibrocystic breast disease: Management of symptoms (pain, tenderness, nodularity) of fibrocystic breast disease which are not reduced by simple measures (including padded brassieres and analgesics) and require suppression of ovarian function.
Hereditary angioedema (HAE), prophylaxis: Prevention of attacks of angioedema of all types (cutaneous, abdominal, laryngeal) in males and females.
Guideline recommendations:Danazol may be considered for short-term pre-procedural and long-term HAE prophylaxis as an alternative to CI inhibitor (human). Danazol is not recommended for treatment of acute HAE attacks (WAO/EEACI [Maurer 2018]).
Off Label Uses
Autoimmune hemolytic anemia
Danazol therapy in conjunction with corticosteroids has shown promising results in treating AIHA in a small number of case series/case reports. Patients dependent on corticosteroids were able to decrease or discontinue the corticosteroids after responding to the addition of danazol. Patients with refractory AIHA and splenectomy also showed favorable response to danazol. Hepatic and androgenic adverse effects may be of concern with danazol therapy. Controlled trials are needed to confirm the safety and efficacy of danazol in treating AIHA.
Immune thrombocytopenia, refractory
In non-controlled studies of danazol as secondary treatment in patients with persistent/chronic refractory immune thrombocytopenia (ITP) who failed to respond to corticosteroids, some patients achieved partial or complete responses. Danazol therapy has demonstrated a partial response in the secondary treatment of chronic refractory ITP in a limited number of case series and case reports; however, very few patients have shown complete response. Some consensus guidelines include danazol as an option for second-line treatment, but note that data from controlled trials are needed to make a specific recommendation.
Hypersensitivity to danazol or any component of the formulation; undiagnosed abnormal genital bleeding; pregnancy; breastfeeding; porphyria; markedly impaired hepatic, renal, or cardiac function; androgen-dependent tumor; active or history of thrombosis or thromboembolic disease
Canadian labeling: Additional contraindications (not in the US labeling): Genital neoplasia; concomitant administration with simvastatin.
Note: In females, begin treatment during menstruation:
Endometriosis (females): Oral:
Mild disease: Initial: 200 to 400 mg/day in 2 divided doses; gradually titrate dosage downward to maintain amenorrhea; continue (uninterrupted) for 3 to 6 months (may extend up to 9 months). If symptoms recur following discontinuation, may reinitiate treatment.
Moderate-to-severe disease or infertility: Initial: 800 mg/day in 2 divided doses; gradually titrate dosage downward to maintain amenorrhea; continue (uninterrupted) for 3 to 6 months (may extend up to 9 months). If symptoms recur following discontinuation, may reinitiate treatment.
Fibrocystic breast disease (females): Oral: Range: 100 to 400 mg/day in 2 divided doses. If symptoms recur following discontinuation, may reinitiate treatment.
Hereditary angioedema (prophylaxis): Oral: Initial: Note: Use minimum effective dose; frequent short courses may lead to side effects associated with long-term use (WAO/EEACI [Maurer 2018]).
Short-term/preprocedural prophylaxis (off-label dose): 2.5 to 10 mg/kg/day; adjust dose according to patient response (maximum: 600 mg/day) (WAO [Craig 2012]). Administer 5 days before and 2 to 3 days after procedure (WAO/EEACI [Maurer 2018]).
Long-term prophylaxis: 100 mg every other day up to 200 mg 2 to 3 times daily; after favorable initial response, decrease the dosage by 50% or less at intervals of 1 to 3 months or longer if the frequency of attacks dictates. If an attack occurs, increase the dosage by up to 200 mg/day; dosages >200 mg/day for an extended period of time are not recommended due to side effects (WAO [Craig 2012]; WAO/EEACI [Maurer 2018]).
Immune thrombocytopenia, refractory (off-label use): Oral: 200 mg 2 to 4 times/day (10 to 15 mg/kg/day in divided doses) (Provan 2010); initial response is observed at 14 to 90 days; may take up to 6 months for peak response (Neunert 2011; Provan 2010) or 600 mg once daily for at least 6 months followed by 400 mg once daily for 3 months, then (if remission maintained) 200 mg once daily (Meloisel 2004).
Refer to adult dosing.
Dosing: Renal Impairment
Use is contraindicated in patients with markedly impaired renal function.
Dosing: Hepatic Impairment
Use is contraindicated in patients with markedly impaired hepatic function.
Endometriosis, fibrocystic breast disease: Initiate therapy during menstruation or ensure patient is not pregnant while on therapy.
Store at 20°C to 25°C (68°F to 77°F). Protect from light.
Ajmaline: Androgens may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy
Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy
ARIPiprazole: CYP3A4 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy
C1 inhibitors: Androgens may enhance the thrombogenic effect of C1 inhibitors. Monitor therapy
CarBAMazepine: Danazol may decrease the metabolism of CarBAMazepine. Monitor therapy
Corticosteroids (Systemic): May enhance the fluid-retaining effect of Androgens. Monitor therapy
CycloSPORINE (Systemic): Androgens may enhance the hepatotoxic effect of CycloSPORINE (Systemic). Androgens may increase the serum concentration of CycloSPORINE (Systemic). Consider therapy modification
Dofetilide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Dofetilide. Monitor therapy
Flibanserin: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Flibanserin. Monitor therapy
HMG-CoA Reductase Inhibitors (Statins): Danazol may increase the serum concentration of HMG-CoA Reductase Inhibitors (Statins). Management: Concurrent use of simvastatin with danazol is contraindicated. Do not exceed 20 mg per day of lovastatin if combined with danazol. Fluvastatin, pravastatin, and rosuvastatin may pose lower risk. Exceptions: Fluvastatin; Pitavastatin; Pravastatin; Rosuvastatin. Consider therapy modification
Lomitapide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Lomitapide. Management: Patients on lomitapide 5 mg/day may continue that dose. Patients taking lomitapide 10 mg/day or more should decrease the lomitapide dose by half. The lomitapide dose may then be titrated up to a max adult dose of 30 mg/day. Consider therapy modification
NiMODipine: CYP3A4 Inhibitors (Weak) may increase the serum concentration of NiMODipine. Monitor therapy
Pimozide: CYP3A4 Inhibitors (Weak) may increase the serum concentration of Pimozide. Avoid combination
Simvastatin: Danazol may increase the serum concentration of Simvastatin. Avoid combination
Tacrolimus (Systemic): Danazol may increase the serum concentration of Tacrolimus (Systemic). Monitor therapy
Tacrolimus (Topical): Danazol may increase the serum concentration of Tacrolimus (Topical). Monitor therapy
Vitamin D Analogs: Danazol may enhance the hypercalcemic effect of Vitamin D Analogs. Exceptions: Calcipotriene; Calcitriol (Topical); Tacalcitol. Monitor therapy
Vitamin K Antagonists (eg, warfarin): Androgens may enhance the anticoagulant effect of Vitamin K Antagonists. Consider therapy modification
Estradiol (Kishino 2010); danazol may interfere with laboratory tests for testosterone, androstenedione, and dehydroepiandrosterone
Frequency not defined.
Cardiovascular: Edema, flushing, hypertension, myocardial infarction, palpitations, syncope, tachycardia
Central nervous system: Depression, dizziness, emotional lability, fatigue, headache, nervousness, paresthesia, sleep disorder, voice disorder (deepening of the voice, hoarseness, instability, sore throat)
Dermatologic: Acne vulgaris, alopecia, diaphoresis, maculopapular rash, papular rash, pruritus, seborrhea, urticaria, vesicular eruption
Endocrine & metabolic: Amenorrhea (may continue post-therapy), change in libido, decreased glucose tolerance (and glucagon changes), decreased HDL cholesterol, decreased thyroxine binding globulin, hirsutism (mild), increased LDL cholesterol, increased thyroxine binding globulin, menstrual disease (altered timing of cycle, spotting), weight gain
Gastrointestinal: Constipation, gastroenteritis, nausea, vomiting
Genitourinary: Asthenospermia, breast atrophy, decreased ejaculate volume, hematuria, inhibition of spermatogenesis, spermatozoa disorder (changes in sperm count and semen viscosity), vaginal dryness, vaginal irritation
Hematologic & oncologic: Abnormal erythrocytes (increased), decreased sex hormone binding globulin, eosinophilia, increased sex hormone-binding globulin, leukocytosis, leukopenia, malignant neoplasm (after prolonged use), petechial rash, polycythemia, purpuric rash, thrombocythemia, thrombocytopenia
Hepatic: Cholestatic jaundice, hepatic adenoma, hepatic neoplasm (malignant; after prolonged use), increased liver enzymes, jaundice, peliosis hepatitis
Neuromuscular & skeletal: Ankylosing spondylitis, arthralgia, back pain, increased creatine phosphokinase, joint swelling, limb pain, muscle cramps, muscle spasm, neck pain, tremor, weakness
Ophthalmic: Visual disturbance
Respiratory: Interstitial pneumonitis
<1%, postmarketing, and/or case reports: Anxiety, carpal tunnel syndrome, cataract, change in appetite, chills, clitoromegaly, convulsions, erythema multiforme, fever, gingival hemorrhage, Guillain-Barre syndrome, hepatotoxicity (idiosyncratic) (Chalasani 2014), nasal congestion, nipple discharge, pancreatitis, pelvic pain, pseudotumor cerebri, purpura (splenic peliosis), skin photosensitivity, Stevens-Johnson syndrome
Concerns related to adverse effects:
• Androgenic effects: May cause nonreversible androgenic effects.
• Blood lipid changes: Anabolic steroids may cause blood lipid changes (decreased high density lipoproteins and increased low density lipoproteins) with increased risk of arteriosclerosis and coronary artery disease.
• Hepatotoxicity: [US Boxed Warning]: Peliosis hepatis and benign hepatic adenoma have been reported with long-term use. Peliosis hepatis and hepatic adenoma may be silent until complicated by acute, potentially life-threatening intraabdominal hemorrhage. Use the lowest effective dose. When used for hereditary angioneurotic edema, if danazol was initiated during an exacerbation due to trauma, stress or other cause, consider periodic attempts to decrease or withdraw therapy. Monitor liver function tests and monitor closely for potential hepatotoxicity during therapy. Use is contraindicated in patients with marked hepatic impairment.
• Intracranial hypertension: [US Boxed Warning]: Danazol is associated with cases of benign intracranial hypertension (also known as pseudotumor cerebri). Early signs and symptoms include papilledema, headache, nausea and vomiting, and visual disturbances. Monitor for symptoms; if symptoms occur, screen for papilledema. Discontinue immediately and refer for neurology care if papilledema is present.
• Thromboembolic events: [US Boxed Warning]: Thromboembolism, thrombotic, and thrombophlebitic events have been reported (including sagittal sinus thrombosis and life-threatening or fatal strokes).
• Diabetes: Use with caution in patients with diabetes mellitus; insulin requirements may be increased; monitor carefully.
• Edematous conditions: Use with caution in patients with conditions influenced by edema (eg, cardiovascular disease, migraine, seizure disorder, renal impairment); danazol may cause fluid retention.
• Fibrocystic breast disease: Breast cancer should be ruled out prior to treatment for fibrocystic breast disease, and if fibrocystic nodules persist or enlarge during danazol treatment. The onset of relief of pain and tenderness is 1 month and symptoms are typically relieved within 2 to 3 months of treatment initiation; elimination of nodularity usually requires 4 to 6 months of continuous therapy. Symptoms of fibrocystic breast disease may recur within 1 year following discontinuation of therapy. Ovulation may not be suppressed at doses used for fibrocystic disease, therefore nonhormonal contraception is recommended.
• Porphyria: May cause exacerbations of acute intermittent porphyria; use is contraindicated in patients with porphyria.
Concurrent drug therapy issues:
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
• Pregnancy: [US Boxed Warning]: Danazol use is contraindicated in pregnancy. Pregnancy should be ruled out immediately prior to starting treatment using a sensitive test (eg, beta subunit test if available) capable of determining early pregnancy. A nonhormonal method of contraception should also be used during therapy. If a patient becomes pregnant during danazol treatment, discontinue danazol and apprise the patient 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.
• Appropriate use: Endometriosis: Danazol is generally reserved for the treatment of pain associated with endometriosis when other agents are not available, due to its high incidence of adverse events (Dunselman 2014).
Liver and renal function tests (periodically); hematologic parameters; lipid panel. Signs and symptoms of intracranial hypertension (papilledema, headache, nausea, vomiting), androgenic changes, and/or fluid retention.
Hereditary angioedema, long-term prophylaxis: CBC, urinalysis, liver function test and lipid profile (baseline, every 6 months while on therapy and 6 months after discontinuation); liver ultrasound (baseline and annually); blood pressure (every 6 months) (WAO [Craig 2012])
Pregnancy Risk Factor
[US Boxed Warning]: Danazol use is contraindicated in pregnancy. Pregnancy should be ruled out immediately prior to starting treatment using a sensitive test (eg, beta subunit test if available) capable of determining early pregnancy. A nonhormonal method of contraception should also be used during therapy. If a patient becomes pregnant during danazol treatment, discontinue danazol and apprise the patient 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.
The use of danazol for the management of hereditary angioedema (HAE) in pregnancy that is not responsive to preferred therapy has been described in case reports (Altman 2006; Boulos 1994; González-Quevedo 2016; Milingos 2009). However, danazol is contraindicated during pregnancy; current guidelines recommend use of other agents in pregnant females (WAO/EEACI [Maurer 2018]).
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience flushing, hair loss, emotional instability, acne, or signs of virilization (in females a deep voice, facial hair, acne, or menstrual changes). Have patient report immediately to prescriber signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), signs of severe cerebrovascular disease (change in strength on one side is greater than the other, difficulty speaking or thinking, change in balance, or vision changes), shortness of breath, excessive weight gain, swelling of arms or legs, severe dizziness, passing out, severe headache, nausea, vomiting, seizures, anxiety, mood changes, lump in breast, signs of blood clots (numbness or weakness on one side of the body; pain, redness, tenderness, warmth, or swelling in the arms or legs; change in color of an arm or leg; angina; shortness of breath; tachycardia; or coughing up blood), breast soreness, sexual dysfunction, or amenorrhea (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
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- Drug class: antigonadotropic agents
Other brands: Danocrine