Hydralazine Hydrochloride And Isosorbide Dinitrate

Contraindications

4 CONTRAINDICATIONS BiDil is contraindicated in patients who are allergic to organic nitrates. Do not use BiDil in patients who are taking PDE-5 inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil. Concomitant use can cause severe hypotension, syncope, or myocardial ischemia [see Drug Interactions (7.1) ] . Do not use BiDil in patients who are taking the soluble guanylate cyclase (sGC) stimulator riociguat. Concomitant use can cause hypotension. Patients who are allergic to organic nitrates ( 4 ) Use of phosphodiesterase type 5 (PDE5) inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil, or soluble guanylate cyclase (sGC) stimulator (riociguat). ( 4 )

Pregnancy & Breastfeeding

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.