Macitentan and tadalafil

Strong CYP3A4 Inducers/Inhibitors: Avoid concomitant use ( 7.2 , 7.3 ) Moderate Dual or Combined CYP3A4 and CYP2C9 Inhibitors: Avoid concomitant use ( 7.4 )

7.1 Nitrates Administration of nitrates within 48 hours after the last dose of OPSYNVI is contraindicated [see Contraindications (4.3) ] .

7.2 Strong CYP3A4 Inducers Strong inducers of CYP3A4 such as rifampin significantly reduce macitentan exposure. Use of OPSYNVI with strong CYP3A4 inducers should be avoided [see Clinical Pharmacology (12.3) ].

7.3 Strong CYP3A4 Inhibitors Concomitant use of strong CYP3A4 inhibitors like ketoconazole increase exposure to both macitentan and tadalafil. Avoid concomitant use of OPSYNVI with strong CYP3A4 inhibitors such as ritonavir, ketoconazole and itraconazole. Use other PAH treatment options when strong CYP3A4 inhibitors are needed [see Clinical Pharmacology (12.3) ].

7.4 Moderate Dual or Combined CYP3A4 and CYP2C9 Inhibitors Concomitant use of moderate dual inhibitors of CYP3A4 and CYP2C9 such as fluconazole is predicted to increase macitentan exposure approximately 4-fold. Avoid concomitant use of OPSYNVI with moderate dual inhibitors of CYP3A4 and CYP2C9 (such as fluconazole and amiodarone) [see Clinical Pharmacology (12.3) ]. Concomitant treatment of both a moderate CYP3A4 inhibitor and moderate CYP2C9 inhibitor with OPSYNVI should also be avoided [see Clinical Pharmacology (12.3) ].

7.5 Alpha-Blockers PDE5 inhibitors, including tadalafil, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. In patients who are taking alpha 1 blockers, concomitant administration of tadalafil may lead to symptomatic hypotension in some patients. Therefore, the combination of OPSYNVI and doxazosin is not recommended [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.2) ].

7.6 Antihypertensives PDE5 inhibitors, including tadalafil, are mild systemic vasodilators. Clinical pharmacology studies were conducted to assess the effect of tadalafil on the potentiation of the blood–pressure–lowering effects of selected antihypertensive medications (amlodipine, angiotensin II receptor blockers, bendroflumethiazide, enalapril, and metoprolol). Small reductions in blood pressure occurred following coadministration of tadalafil with these agents compared with placebo [see Clinical Pharmacology (12.2) ].

7.7 Alcohol Both alcohol and tadalafil, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure–lowering effects of each individual compound may be increased. Substantial consumption of alcohol (e.g., 5 units or greater) in combination with OPSYNVI can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache. Tadalafil (10 mg or 20 mg) did not affect alcohol plasma concentrations and alcohol did not affect tadalafil plasma concentrations [see Clinical Pharmacology (12.2) ].

8.1 Pregnancy Risk Summary Based on data from animal reproduction studies, OPSYNVI is contraindicated during pregnancy. Macitentan, a component of OPSYNVI, may cause embryo-fetal toxicity, including birth defects and fetal death, when administered to a pregnant female. Available data from postmarketing reports and published literature over decades of use with ERAs in the same class as OPSYNVI have not identified an increased risk of major birth defects; however, these data are limited. Methodological limitations of these postmarketing reports and published literature include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and missing data.

These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal ERA use. Macitentan was teratogenic in rabbits and rats at all doses tested. Available data from a randomized controlled trial, observational studies, and case series with tadalafil use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes.

In tadalafil animal reproduction studies, no adverse developmental effects were observed with oral administration of tadalafil to pregnant rats and mice during organogenesis at exposures 7 times the maximum recommended human dose (MRHD) of 40 mg/day (see Data ) . There are risks to the mother and the fetus associated with PAH in pregnancy (see Clinical Considerations ) . If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, advise pregnant women of the potential risk to a fetus [see Contraindications (4.1) and Warnings and Precautions (5.1) ]. The background risk of major birth defects and miscarriage for the indicated population is unknown.

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 In patients with PAH, pregnancy is associated with an increased rate of maternal and fetal morbidity and mortality, including heart failure, stroke, spontaneous abortion, intrauterine growth restriction, premature labor, and preterm birth. Data Animal Data Macitentan In both rabbits and rats, there were cardiovascular and mandibular arch fusion abnormalities.

Administration of macitentan to female rats from late…