BiDil

Clinical summary

Indications and usage 1 INDICATIONS AND USAGE BiDil is a combination of isosorbide dinitrate, a nitrate vasodilator, and hydralazine hydrochloride, an arteriolar vasodilator, indicated for: the treatment of heart failure as an adjunct therapy to standard therapy in self-identified black patients to improve survival, prolong time to hospitalization for heart failure and to improve patient-reported functional status ( 1.1 ) Limitations of use: There is little experience in patients with NYHA class IV heart failure ( 1.2 ) 1.1 Treatment of Heart Failure in Self-identified Black Patients BiDil is indicated for the treatment of heart failure as an adjunct to standard therapy in self-identified black patients to improve survival, to prolong time to hospitalization for heart failure, and to improve patient-reported functional status. 1.2 Limitations of Use There is little experience in patients with NYHA class IV heart failure. Dosage and administration 2 DOSAGE AND ADMINISTRATION BiDil should be initiated at a dose of one BiDil Tablet, three times a day. Titrate to a maximum of two tablets three times daily, if tolerated. Although titration of BiDil can be rapid (3-5 days), some patients may experience side effects and may take longer to reach their maximum tolerated dose. The dosage may be decreased to as little as one-half BiDil Tablet three times a day if intolerable side effects occur. Efforts should be made to titrate up as soon as side effects subside. One tablet three times a day titrated to a maximum tolerated dose up to two tablets three times a day ( 2 ) Dosage may be decreased to as little as one-half tablet three times a day if intolerable side effects occur. Efforts should be made to titrate up as soon as side effects subside ( 2 ) Warnings and cautions 5 WARNINGS AND PRECAUTIONS May cause symptomatic hypotension ( 5.1 ) Symptomatic Lupus Erythematosus Syndromes: Consider discontinuation if clinically appropriate ( 5.2 ) Myocardial ischemia and angina ( 5.3 ) Peripheral Neuritis : May be treated with Pyridoxine ( 5.4 ) 5.1 Hypotension Symptomatic hypotension, particularly with upright posture, may occur with even small doses of BiDil. Hypotension is most likely to occur in patients who have been volume or salt depleted; correct prior to initiation of BiDil [see Adverse Reactions (6.1) ] . 5.2 Systemic Lupus Erythematosus Hydralazine hydrochloride has been reported to cause a drug-induced systemic lupus erythematosus (SLE) syndrome. Symptoms and signs usually regress when hydralazine hydrochloride is discontinued. 5.3 Worsening Ischemic Heart Disease Hydralazine hydrochloride can cause tachycardia and hypotension potentially leading to myocardial ischemia and angina, particularly in patients with hypertrophic cardiomyopathy. 5.4 Peripheral Neuritis Hydralazine hydrochloride has been associated with peripheral neuritis, evidenced by paresthesia, numbness, and tingling, which may be related to an antipyridoxine effect. Pyridoxine should be added to BiDil therapy if such symptoms develop. Drug interactions 7 DRUG INTERACTIONS 7.1 Phosphodiesterase Inhibitors BiDil is contraindicated in patients who are using a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), PDE5 inhibitors such as avanafil, sildenafil, vardenafil, and tadalafil have been shown to potentiate the hypotensive effects of organic nitrates. Do not use BiDil in patients who are taking the soluble guanylate cyclase (sGC) stimulator riociguat. Concomitant use can cause hypotension [see Contraindications (4) ] . Pregnancy 8.1 Pregnancy Risk Summary There are no data on BiDil use in pregnant women, and insufficient data on its components (hydralazine and isosorbide dinitrate) to assess a drug-associated risk of major birth defects or miscarriage with first trimester use. Available published data on hydralazine use in pregnancy during the second and third trimesters have not shown an association with adverse pregnancy-related outcomes. Hydralazine hydrochloride is teratogenic in mice at 66 mg/kg and possibly in rabbits at 33 mg/kg (2 and 3 times the MRHD of BiDil on a body surface area basis). Isosorbide dinitrate has been shown to cause a dose-related increase in embryo-toxicity (excess mummified pups) in rabbits at 70 mg/kg (12 times the MRHD of BiDil on a body surface area basis). All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women with heart failure are at increased risk for preterm birth. Clinical classification of heart disease may worsen with pregnancy and lead to maternal death and/or stillbirth.