GENOSYL

5 WARNINGS AND PRECAUTIONS Rebound Pulmonary Hypertension: Abrupt discontinuation of GENOSYL 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, GENOSYL may increase pulmonary capillary wedge pressure leading to pulmonary edema ( 5.4 ). 5.1 Rebound Pulmonary Hypertension Syndrome following Abrupt Discontinuation Wean from GENOSYL [see Dosage and Administration (2.2) ]. Abrupt discontinuation of GENOSYL 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 GENOSYL 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 GENOSYL; it can take 8 hours or more before steady-state methemoglobin levels are attained. Monitor methemoglobin and adjust the dose of GENOSYL to optimize oxygenation. If methemoglobin levels do not resolve with decrease in dose or discontinuation of GENOSYL, 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 0.5 ppm when measured in the breathing circuit, then the delivery system should be assessed in accordance with the GENOSYL Delivery System Operator's Manual troubleshooting section, and the NO 2 analyzer should be recalibrated. The dose of GENOSYL and/or FiO 2 should be adjusted as appropriate. 5.4 Worsening Heart Failure Patients with left ventricular dysfunction treated with GENOSYL may experience pulmonary edema, increased pulmonary capillary wedge pressure, worsening of left ventricular dysfunction, systemic hypotension, bradycardia and cardiac arrest. Discontinue GENOSYL while providing symptomatic care.

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) ] The most common adverse reaction is hypotension ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Vero Biotech at 1-877-337-4118 and http://www.vero-biotech.com/ or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 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 gas for inhalation, 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 gas for inhalation and placebo-treated groups. From all controlled studies, at least 6 months of follow-up is available for 278 patients who received nitric oxide gas and 212 patients who received placebo. Among these patients, there was no evidence of an adverse effect of treatment on the need for re-hospitalization, special medical services, pulmonary disease, and 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 gas for inhalation than on placebo) was hypotension (14% vs. 11%). 6.2 Postmarketing Experience Post marketing reports of accidental exposure to nitric oxide for inhalation in hospital staff have been associated with chest discomfort, dizziness, dry throat, dyspnea, and headache.