Epoprostenol

1 INDICATIONS AND USAGE Epoprostenol for injection is indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) to improve exercise capacity. Studies establishing effectiveness included predominantly patients with NYHA Functional Class III-IV symptoms and etiologies of idiopathic or heritable PAH or PAH associated with connective tissue diseases. Epoprostenol for injection is a prostacyclin vasodilator indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) to improve exercise capacity. Studies establishing effectiveness included predominantly patients with NYHA Functional Class III-IV symptoms and etiologies of idiopathic or heritable PAH or PAH associated with connective tissue diseases. ( 1 )

12.1 Mechanism of Action Epoprostenol has 2 major pharmacological actions: (1) direct vasodilation of pulmonary and systemic arterial vascular beds, and (2) inhibition of platelet aggregation.

2 DOSAGE AND ADMINISTRATION Important Note: Reconstitute Epoprostenol for Injection only as directed with Sterile Water for Injection, USP, or Sodium Chloride 0.9% Injection, USP. Do not dilute reconstituted solutions of epoprostenol for injection or administer it with other parenteral solutions or medications [see Dosage and Administration (2.4) ]. • Dosage - Infusion of epoprostenol for injection should be initiated at 2 ng/kg/min and increased in increments of 2 ng/kg/min every 15 minutes or longer until dose-limiting pharmacologic effects are elicited or until a tolerance limit to the drug is established. ( 2.1 ) - If symptoms of pulmonary hypertension persist or recur after improving - the infusion should be increased by 1 ng/kg/min to 2 ng/kg/min increments at intervals sufficient to allow assessment of clinical response; these intervals should be at least 15 minutes. ( 2.2 ) • Administration - Epoprostenol for injection is administered by continuous intravenous infusion via a central venous catheter using an ambulatory infusion pump. ( 2.3 ) - Do not mix with any other parenteral medications or solutions prior to or during administration. ( 2.4 ) • Reconstitution - Reconstituted in vial with only 5 mL of either Sterile Water for Injection or Sodium Chloride 0.9% Injection. - Epoprostenol for injection solution reconstituted and immediately diluted to the final concentration in the drug delivery reservoir can be administered per the conditions of use as outlined in Table 1. ( 2.4 ) - Solution for chronic delivery should be prepared in a drug delivery reservoir appropriate for the infusion pump. ( 2.4 ) 2.1 Dosage Prepare continuous chronic infusion of epoprostenol for injection as directed, and administer through a central venous catheter. Temporary peripheral intravenous infusion may be used until central access is established. Initiate chronic infusion of epoprostenol for injection at 2 ng/kg/min and increase in increments of 2 ng/kg/min every 15 minutes or longer until a tolerance limit to the drug is established or further increases in the infusion rate are not clinically warranted. If dose-limiting pharmacologic effects occur, then decrease the infusion rate until epoprostenol for injection is tolerated. In clinical trials, the most common dose-limiting adverse events were nausea, vomiting, hypotension, sepsis, headache, abdominal pain, or respiratory disorder (most treatment-limiting adverse events were not serious). If the initial infusion rate of 2 ng/kg/min is not tolerated, use a lower dose. In the controlled 12-week trial in PAH/SSD, for example, the dose increased from a mean starting dose of 2.2 ng/kg/min. During the first 7 days of treatment, the dose was increased daily to a mean dose of 4.1 ng/kg/min on day 7 of treatment. At the end of week 12, the mean dose was 11.2 ng/kg/min. The mean incremental increase was 2 ng/kg/min to 3 ng/kg/min every 3 weeks. 2.2 Dosage Adjustments Base changes in the chronic infusion rate on persistence, recurrence, or worsening of the patient’s symptoms of pulmonary hypertension and the occurrence of adverse events due to excessive doses of epoprostenol for injection. In general, expect increases in dose from the initial chronic dose. Consider increments in dose if symptoms of pulmonary hypertension persist or recur. Adjust the infusion by 1 ng/kg/min to 2 ng/kg/min increments at intervals sufficient to allow assessment of clinical response; these intervals should be at least 15 minutes. In clinical trials, incremental increases in dose occurred at intervals of 24 to 48 hours or longer. Following establishment of new chronic infusion rate, observe the patient, and monitor standing and supine blood pressure and heart rate for several hours to ensure that the new dose is tolerated. During chronic infusion, the occurrence of dose-limiting pharmacological events may necessitate a decrease in infusion rate, but the adverse event may occasionally resolve without dosage adjustment.

6 ADVERSE REACTIONS • Most common adverse reactions during: - Dose Initiation and Escalation: Nausea, vomiting, headache, hypotension, flushing, chest pain, anxiety, dizziness, bradycardia, dyspnea, abdominal pain, musculoskeletal pain, and tachycardia ( 6.1 ) - Chronic Dosing: Headache, jaw pain, flushing, diarrhea, nausea and vomiting, flu-like symptoms, and anxiety/nervousness ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mylan at 1-877-446-3679 (1-877-4-INFO-RX) 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. During clinical trials, adverse events were classified as follows: (1) adverse events during dose initiation and escalation, (2) adverse events during chronic dosing, and (3) adverse events associated with the drug delivery system. Adverse Events during Dose Initiation and Escalation During early clinical trials, epoprostenol was increased in 2 ng/kg/min increments until the patients developed symptomatic intolerance. The most common adverse events and the adverse events that limited further increases in dose were generally related to vasodilation, the major pharmacologic effect of epoprostenol. The most common dose-limiting adverse events (occurring in > 1% of patients) were nausea, vomiting, headache, hypotension, and flushing, but also include chest pain, anxiety, dizziness, bradycardia, dyspnea, abdominal pain, musculoskeletal pain, and tachycardia. Table 8 lists the adverse events reported during dose initiation and escalation in decreasing order of frequency. Table 8: Adverse Events during Dose Initiation and Escalation Adverse Events Occurring in > 1% of Patients Epoprostenol (n=391) Flushing 58% Headache 49% Nausea/vomiting 32% Hypotension 16% Anxiety, nervousness, agitation 11% Chest pain 11% Dizziness 8% Bradycardia 5% Abdominal pain 5% Musculoskeletal pain 3% Dyspnea 2% Back pain 2% Sweating 1% Dyspepsia 1% Hypesthesia/paresthesia 1% Tachycardia 1% Adverse Events during Chronic Administration Interpretation of adverse events is complicated by the clinical features of PAH, which are similar to some of the pharmacologic effects of epoprostenol (e.g., dizziness, syncope). Adverse events which may be related to the underlying disease include dyspnea, fatigue, chest pain, edema, hypoxia, right ventricular failure, and pallor. Several adverse events, on the other hand, can clearly be attributed to epoprostenol. These include hypotension, bradycardia, tachycardia, pulmonary edema, bleeding at various sites, thrombocytopenia, headache, abdominal pain, pain (unspecified), sweating, rash, arthralgia, jaw pain, flushing, diarrhea, nausea and vomiting, flu-like symptoms, anxiety/nervousness, and agitation. In addition, chest pain, fatigue, and pallor have been reported during epoprostenol therapy, and a role for the drug in these events cannot be excluded. Adverse Events during Chronic Administration for Idiopathic or Heritable PAH In an effort to separate the adverse effects of the drug from the adverse effects of the underlying disease, Table 9 lists adverse events that occurred at a rate at least 10% greater on epoprostenol than on conventional therapy in controlled trials for idiopathic or heritable PAH. Table 9: Adverse Events Regardless of Attribution Occurring in Patients with Idiopathic or Heritable PAH with ≥10% Difference between Epoprostenol and Conventional Therapy Alone Adverse Event Epoprostenol (n = 52) Conventional Therapy (n = 54) Occurrence More Common With Epoprostenol General Chills/fever/sepsis/flu-like symptoms 25% 11% Cardiovascular Tachycardia 35% 24% Flushing 42% 2% Gastrointestinal Diarrhea 37% 6% Nausea/vomiting 67% 48% Musculoskeletal Jaw pain 54% 0% Myalgia 44% 31% Nonspecific musculoskelet

5 WARNINGS AND PRECAUTIONS • Do not abruptly lower the dose or withdraw dosing. All dosing initiation and changes should be closely monitored. ( 5.2 , 5.3 ) 5.1 Dose Initiation Epoprostenol is a potent pulmonary and systemic vasodilator. Initiate epoprostenol in a setting with adequate personnel and equipment for physiologic monitoring and emergency care. Dose initiation has been performed during right heart catheterization and without cardiac catheterization. During dose initiation, asymptomatic increases in pulmonary artery pressure coincident with increases in cardiac output occurred rarely. In such cases, consider dose reduction, but such an increase does not imply that chronic treatment is contraindicated. 5.2 Chronic Use and Dose Adjustment During chronic use, deliver epoprostenol continuously on an ambulatory basis through a permanent indwelling central venous catheter. Unless contraindicated, administer anticoagulant therapy to patients receiving epoprostenol to reduce the risk of pulmonary thromboembolism or systemic embolism through a patent foramen ovale. To reduce the risk of infection, use aseptic technique in the reconstitution and administration of epoprostenol and in routine catheter care. Because epoprostenol is metabolized rapidly, even brief interruptions in the delivery of epoprostenol may result in symptoms associated with rebound pulmonary hypertension including dyspnea, dizziness, and asthenia. Intravenous therapy with epoprostenol will likely be needed for prolonged periods, possibly years, so consider the patient’s capacity to accept and care for a permanent intravenous catheter and infusion pump. Based on clinical trials, the acute hemodynamic response (reduction in pulmonary artery resistance) to epoprostenol did not correlate well with improvement in exercise tolerance or survival during chronic use of epoprostenol. Adjust dosage of epoprostenol during chronic use at the first sign of recurrence or worsening of symptoms attributable to pulmonary hypertension or the occurrence of adverse events associated with epoprostenol [see Dosage and Administration (2.2) ] . Following dosage adjustments, monitor standing and supine blood pressure and heart rate closely for several hours. 5.3 Withdrawal Effects Abrupt withdrawal (including interruptions in drug delivery) or sudden large reductions in dosage of epoprostenol may result in symptoms associated with rebound pulmonary hypertension, including dyspnea, dizziness, and asthenia. In clinical trials, one Class III primary pulmonary hypertension patient’s death was judged attributable to the interruption of epoprostenol. Avoid abrupt withdrawal.

4 CONTRAINDICATIONS A large study evaluating the effect of epoprostenol on survival in NYHA Class III and IV patients with congestive heart failure due to severe left ventricular systolic dysfunction was terminated after an interim analysis of 471 patients revealed a higher mortality in patients receiving epoprostenol plus conventional therapy than in those receiving conventional therapy alone. The chronic use of epoprostenol in patients with congestive heart failure due to severe left ventricular systolic dysfunction is therefore contraindicated. Some patients with pulmonary hypertension have developed pulmonary edema during dose initiation, which may be associated with pulmonary veno-occlusive disease. Epoprostenol should not be used chronically in patients who develop pulmonary edema during dose initiation. Epoprostenol is also contraindicated in patients with known hypersensitivity to the drug or to structurally related compounds. • Congestive heart failure due to severe left ventricular systolic dysfunction ( 4 ) • Pulmonary edema (4) • Hypersensitivity to the drug or to structurally related compounds ( 4 )

10 OVERDOSAGE Signs and symptoms of excessive doses of epoprostenol during clinical trials are the expected dose-limiting pharmacologic effects of epoprostenol, including flushing, headache, hypotension, tachycardia, nausea, vomiting, and diarrhea. Treatment will ordinarily require dose reduction of epoprostenol. One patient with secondary pulmonary hypertension accidentally received 50 mL of an unspecified concentration of epoprostenol. The patient vomited and became unconscious with an initially unrecordable blood pressure. Epoprostenol was discontinued and the patient regained consciousness within seconds. In clinical practice, fatal occurrences of hypoxemia, hypotension, and respiratory arrest have been reported following overdosage of epoprostenol. Single intravenous doses of epoprostenol at 10 and 50 mg/kg (2,703 and 27,027 times the recommended acute phase human dose based on body surface area) were lethal to mice and rats, respectively. Symptoms of acute toxicity were hypoactivity, ataxia, loss of righting reflex, deep slow breathing, and hypothermia.