Noxivent 102

INDICATIONS AND USAGE Noxivent™ is a vasodilator indicated to improve oxygenation and reduce the need for extracorporeal membrane oxygenation in term and near-term (>34 weeks gestation) neonates with hypoxic respiratory failure associated with clinical or echocardiographic evidence of pulmonary hypertension in conjunction with ventilatory support and other appropriate agents. 1. INDICATIONS AND USAGE Noxivent™ is indicated to improve oxygenation and reduce the need for extracorporeal membrane oxygenation in term and near-term (>34 weeks gestation) neonates with hypoxic respiratory failure associated with clinical or echocardiographic evidence of pulmonary hypertension in conjunction with ventilatory support and other appropriate agents.

DOSAGE AND ADMINISTRATION The recommended dose is 20 ppm, maintained for up to 14 days or until the underlying oxygen desaturation has resolved ( 2.1 ). Doses greater than 20 ppm are not recommended ( 2.1 , 5.2 ) Administration: • Avoid abrupt discontinuation ( 2.2 , 5.1 ). 2. DOSAGE AND ADMINISTRATION 2.1 Dosage Term and near-term neonates with hypoxic respiratory failure The recommended dose of Noxivent™ is 20 ppm. Maintain treatment up to 14 days or until the underlying oxygen desaturation has resolved and the neonate is ready to be weaned from Noxivent™ therapy. Doses greater than 20 ppm are not recommended [see Warnings and Precautions (5.2) ]. 2.2 Administration Nitric Oxide Delivery Systems Noxivent™ must be administered using a calibrated FDA-cleared Nitric Oxide Delivery System (NODS). There are various FDA-cleared NODS; refer to the NODS labeling to determine which NODS to use with this drug product and for needed information on training and technical support for users of this drug product with the NODS. Do not use Noxivent with Inomax DSIR Plus and DSIP MRI NODS. Do not use Noxivent in the MPI suite. Keep available a backup battery power supply and an independent reserve nitric oxide delivery system to address power and system failures. Monitoring Measure methemoglobin within 4-8 hours after initiation of treatment with Noxivent™ and periodically throughout treatment [see Warnings and Precautions (5.2 )]. Monitor for PaO 2 and inspired NO 2 during Noxivent™ administration [see Warnings and Precautions 5.3 )]. Weaning and Discontinuatio n Avoid abrupt discontinuation of Noxivent™ [see Warnings and Precautions (5.1 )]. To wean Noxivent™, downtitrate in several steps, pausing several hours at each step to monitor for hypoxemia.

WARNINGS AND PRECAUTIONS Rebound: Abrupt discontinuation of Noxivent™ may lead to worsening oxygenation and increasing pulmonary artery pressure ( 5.1 ). Methemoglobinemia: Methemoglobin increases with the dose of nitric oxide; following discontinuation or reduction of nitric oxide, methemoglobin levels return to baseline over a period of hours ( 5.2 ). Elevated NO 2 Levels: Monitor NO 2 levels ( 5.3 ). Heart Failure: In patients with pre-existing left ventricular dysfunction, Noxivent™ may increase pulmonary capillary wedge pressure leading to pulmonary edema ( 5.4 ). 5. WARNINGS AND PRECAUTIONS 5.1 Rebound Pulmonary Hypertension Syndrome following Abrupt Discontinuation Wean from Noxivent™ [see Dosage and Administration (2.2 )]. Abrupt discontinuation of Noxivent™ may lead to worsening oxygenation and increasing pulmonary artery pressure, i.e., Rebound Pulmonary Hypertension Syndrome. Signs and symptoms of Rebound Pulmonary Hypertension Syndrome include hypoxemia, systemic hypotension, bradycardia, and decreased cardiac output. If Rebound Pulmonary Hypertension occurs, reinstate Noxivent™ therapy immediately. 5.2 Hypoxemia from Methemoglobinemia Nitric oxide combines with hemoglobin to form methemoglobin, which does not transport oxygen. Methemoglobin levels increase with the dose of Noxivent™; it can take 8 hours or more before steady-state methemoglobin levels are attained. Monitor methemoglobin and adjust the dose of Noxivent™ to optimize oxygenation. If methemoglobin levels do not resolve with decrease in dose or discontinuation of Noxivent™, additional therapy may be warranted to treat methemoglobinemia [see Overdosage (10 )]. 5.3 Airway Injury from Nitrogen Dioxide Nitrogen dioxide (NO 2 ) forms in gas mixtures containing NO and O 2 . Nitrogen dioxide may cause airway inflammation and damage to lung tissues. If there is an unexpected change in NO 2 concentration, or if the NO 2 concentration reaches 3 ppm when measured in the breathing circuit, then the delivery system should be assessed in accordance with the Nitric Oxide Delivery System O&M Manual troubleshooting section, and the NO 2 analyzer should be recalibrated. The dose of Noxivent™ and/or FiO 2 should be adjusted as appropriate. 5.4 Worsening Heart Failure Patients with left ventricular dysfunction treated with Noxivent™ may experience pulmonary edema, increased pulmonary capillary wedge pressure, worsening of left ventricular dysfunction, systemic hypotension, bradycardia and cardiac arrest. Discontinue Noxivent™ while providing symptomatic care.

CONTRAINDICATIONS Neonates dependent on right-to-left shunting of blood ( 4 ). 4. CONTRAINDICATIONS Noxivent™ is contraindicated in neonates dependent on right-to-left shunting of blood.

DRUG INTERACTIONS Nitric oxide donor compounds may increase the risk of developing methemoglobinemia ( 7 ). Revised: 08/2023 7. DRUG INTERACTIONS 7.1 Nitric Oxide Donor Agents Nitric oxide donor agents such as prilocaine, sodium nitroprusside and nitroglycerine may increase the risk of developing methemoglobinemia.

ADVERSE REACTIONS The most common adverse reaction is hypotension. ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Linde, Inc. at 1-800-772-9247 and www.linde.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6. ADVERSE REACTIONS The following adverse reactions are discussed elsewhere in the label; Hypoxemia [see Warnings and Precautions (5.2 )] Worsening Heart Failure [see Warnings and Precautions (5.4 )] 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction information from the clinical studies does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates. Controlled studies have included 325 patients on nitric oxide doses of 5 to 80 ppm and 251 patients on placebo. Total mortality in the pooled trials was 11% on placebo and 9% on nitric oxide, a result adequate to exclude nitric oxide mortality being more than 40% worse than placebo. In both the NINOS and CINRGI studies, the duration of hospitalization was similar in nitric oxide and placebo-treated groups. From all controlled studies, at least 6 months of follow-up is available for 278 patients who received nitric oxide and 212 patients who received placebo. Among these patients, there was no evidence of an adverse effect of treatment on the need for rehospitalization, special medical services, pulmonary disease, or neurological sequelae. In the NINOS study, treatment groups were similar with respect to the incidence and severity of intracranial hemorrhage, Grade IV hemorrhage, periventricular leukomalacia, cerebral infarction, seizures requiring anticonvulsant therapy, pulmonary hemorrhage, or gastrointestinal hemorrhage. In CINRGI, the only adverse reaction (>2% higher incidence on nitric oxide than on placebo) was hypotension (14% vs. 11%). 6.2 Post-Marketing Experience Post marketing reports of accidental exposure to nitric oxide for inhalation in hospital staff has been associated with chest discomfort, dizziness, dry throat, dyspnea, and headache.

12. CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Nitric oxide relaxes vascular smooth muscle by binding to the heme moiety of cytosolic guanylate cyclase, activating guanylate cyclase and increasing intracellular levels of cyclic guanosine 3',5'-monophosphate, which then leads to vasodilation. When inhaled, nitric oxide selectively dilates the pulmonary vasculature, and because of efficient scavenging by hemoglobin, has minimal effect on the systemic vasculature. Noxivent™ appears to increase the partial pressure of arterial oxygen (PaO 2 ) by dilating pulmonary vessels in better ventilated areas of the lung, redistributing pulmonary blood flow away from lung regions with low ventilation/perfusion (V/Q) ratios toward regions with normal ratios. 12.2 Pharmacodynamics Effects on Pulmonary Vascular Tone in PPHN Persistent pulmonary hypertension of the newborn (PPHN) occurs as a primary developmental defect or as a condition secondary to other diseases such as meconium aspiration syndrome (MAS), pneumonia, sepsis, hyaline membrane disease, congenital diaphragmatic hernia (CDH), and pulmonary hypoplasia. In these states, pulmonary vascular resistance (PVR) is high, which results in hypoxemia secondary to right-to-left shunting of blood through the patent ductus arteriosus and foramen ovale. In neonates with PPHN, Noxivent™ improves oxygenation (as indicated by significant increases in PaO 2 ). 12.3 Pharmacokinetics The pharmacokinetics of nitric oxide has been studied in adults. Absorption and Distribution Nitric oxide is absorbed systemically after inhalation. Most of it traverses the pulmonary capillary bed where it combines with hemoglobin that is 60% to 100% oxygen-saturated. At this level of oxygen saturation, nitric oxide combines predominantly with oxyhemoglobin to produce methemoglobin and nitrate. At low oxygen saturation, nitric oxide can combine with deoxyhemoglobin to transiently form nitrosylhemoglobin, which is converted to nitrogen oxides and methemoglobin upon exposure to oxygen. Within the pulmonary system, nitric oxide can combine with oxygen and water to produce nitrogen dioxide and nitrite, respectively, which interact with oxyhemoglobin to produce methemoglobin and nitrate. Thus, the end products of nitric oxide that enter the systemic circulation are predominantly methemoglobin and nitrate. Metabolism Methemoglobin disposition has been investigated as a function of time and nitric oxide exposure concentration in neonates with respiratory failure. The methemoglobin (MetHb) concentration-time profiles during the first 12 hours of exposure to 0, 5, 20, and 80 ppm nitric oxide are shown in Figure 1. Figure 1: Methemoglobin Concentration-Time Profiles Neonates Inhaling 0, 5, 20 or 80 ppm Nitric Oxide Hours of Nitric Oxide Administration Methemoglobin concentrations increased during the first 8 hours of nitric oxide exposure. The mean methemoglobin level remained below 1% in the placebo group and in the 5 ppm and 20 ppm nitric oxide groups, but reached approximately 5% in the 80-ppm nitric oxide group. Methemoglobin levels >7% were attained only in patients receiving 80 ppm, where they comprised 35% of the group. The average time to reach peak methemoglobin was 10 ± 9 (SD) hours (median, 8 hours) in these 13 patients, but one patient did not exceed 7% until 40 hours. Elimination Nitrate has been identified as the predominant nitric oxide metabolite excreted in the urine, accounting for >70% of the nitric oxide dose inhaled. Nitrate is cleared from the plasma by the kidney at rates approaching the rate of glomerular filtration. hrs admin