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 musculoskeletal pain | 35% | 15% |
| Neurological | | |
| Anxiety/nervousness/tremor | 21% | 9% |
| Dizziness | 83% | 70% |
| Headache | 83% | 33% |
| Hypesthesia, hyperesthesia, paresthesia | 12% | 2% |
Thrombocytopenia has been reported during uncontrolled clinical trials in patients receiving epoprostenol.
Adverse Events during Chronic Administration for PAH/SSD
In an effort to separate the adverse effects of the drug from the adverse effects of the underlying disease, Table 10 lists adverse events that occurred at a rate at least 10% greater on epoprostenol in the controlled trial.
Table 10: Adverse Events Regardless of Attribution Occurring in Patients with PAH/SSD With ≥10% Difference Between Epoprostenol and Conventional Therapy Alone| Adverse Event | Epoprostenol (n=56) | Conventional Therapy (n=55) |
|---|
| Cardiovascular | | |
| Flushing | 23% | 0% |
| Hypotension | 13% | 0% |
| Gastrointestinal | | |
| Anorexia | 66% | 47% |
| Nausea/vomiting | 41% | 16% |
| Diarrhea | 50% | 5% |
| Musculoskeletal | | |
| Jaw pain | 75% | 0% |
| Pain/neck pain/arthralgia | 84% | 65% |
| Neurological | | |
| Headache | 46% | 5% |
| Skin and Appendages | | |
| Skin ulcer | 39% | 24% |
| Eczema/rash/urticaria | 25% | 4% |
Although the relationship to epoprostenol administration has not been established, pulmonary embolism has been reported in several patients taking epoprostenol and there have been reports of hepatic failure.
Adverse Events Attributable to the Drug Delivery System
Chronic infusions of epoprostenol are delivered using a small, portable infusion pump through an indwelling central venous catheter. During controlled PAH trials of up to 12 weeks' duration, the local infection rate was about 18%, and the rate for pain was about 11%. During long-term follow-up, sepsis was reported at a rate of 0.3 infections/patient per year in patients treated with epoprostenol. This rate was higher than reported in patients using chronic indwelling central venous catheters to administer parenteral nutrition, but lower than reported in oncology patients using these catheters. Malfunctions in the delivery system resulting in an inadvertent bolus of or a reduction in epoprostenol were associated with symptoms related to excess or insufficient epoprostenol, respectively
Risk Summary
Limited published data from case series and case reports with VELETRI have not established a drug associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes when used during pregnancy. There are risks to the mother and fetus from untreated pulmonary arterial hypertension (see Clinical Considerations). In animal reproduction studies, pregnant rats and rabbits received epoprostenol sodium during organogenesis at exposures of 2.5 and 4.8 times the maximum recommended human dose (MRHD), respectively, and there was no effect on the fetus (see Data).
The estimated 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% to 4% and 15% to 20%, respectively.
Clinical Considerations
Disease-Associated Maternal and/or Embryo/Fetal Risk
Pregnant women with untreated pulmonary arterial hypertension are at risk for heart failure, stroke, preterm delivery, and maternal and fetal death.
Data
Animal Data
Embryo-fetal development studies have been performed in rats and rabbits during organogenesis. Epoprostenol sodium doses up to 100 mcg/kg/day, a dose that was maternally toxic in rabbits but not in rats, (600 mcg/m2/day in rats, 2.5 times the MRHD, and 1,180 mcg/m2/day in rabbits, 4.8 times the MRHD based on body surface area), had no effect on the fetus.
In a postnatal development study, epoprostenol sodium was administered subcutaneously to female rats for 2 weeks prior to mating through weaning and to male rats for 60 days prior to and through mating at a male and female toxic dose of up to 100 mcg/kg/day (600 mcg/m2/day, 2.5 times the MRHD based on body surface area). There was no effect on growth and development of the offspring.
Risk Summary
There are no data on the presence of epoprostenol in either human or animal milk, the effects on the breastfed infant, or the effect on milk production.
The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VELETRI and any potential adverse effects on the breastfed child from epoprostenol or from the underlying maternal condition.
Acute Hemodynamic Effects
Acute intravenous infusions of epoprostenol for up to 15 minutes in patients with idiopathic or heritable PAH or PAH associated with scleroderma spectrum of diseases (PAH/SSD) produce dose-related increases in cardiac index (CI) and stroke volume (SV) and dose-related decreases in pulmonary vascular resistance (PVR), total pulmonary resistance (TPR), and mean systemic arterial pressure (SAPm). The effects of epoprostenol on mean pulmonary arterial pressure (PAPm) were variable and minor.
Chronic Infusion in Idiopathic or Heritable PAH
Hemodynamic Effects
Chronic continuous infusions of epoprostenol in patients with idiopathic or heritable PAH were studied in 2 prospective, open, randomized trials of 8 and 12 weeks' duration comparing epoprostenol plus conventional therapy to conventional therapy alone. Dosage of epoprostenol was determined as described in Dosage and Administration (2) and averaged 9.2 ng/kg/min at study's end. Conventional therapy varied among patients and included some or all of the following: anticoagulants in essentially all patients; oral vasodilators, diuretics, and digoxin in one half to two thirds of patients; and supplemental oxygen in about half the patients. Except for 2 New York Heart Association (NYHA) functional Class II patients, all patients were either functional Class III or Class IV. As results were similar in the 2 studies, the pooled results are described.
Chronic hemodynamic effects were generally similar to acute effects. Increases in CI, SV, and arterial oxygen saturation and decreases in PAPm, mean right atrial pressure (RAPm), TPR, and systemic vascular resistance (SVR) were observed in patients who received epoprostenol chronically compared to those who did not. Table 11 illustrates the treatment-related hemodynamic changes in these patients after 8 or 12 weeks of treatment.
Table 11: Hemodynamics during Chronic Administration of Epoprostenol in Patients with Idiopathic or Heritable PAH | Baseline | Mean Change from Baseline at End of Treatment Period At 8 weeks: Epoprostenol N=10, conventional therapy N=11 (N is the number of patients with hemodynamic data). At 12 weeks: Epoprostenol N=38, conventional therapy N=30 (N is the number of patients with hemodynamic data). |
|---|
| Hemodynamic Parameter | Epoprostenol (N=52) | Standard Therapy (N=54) | Epoprostenol (N=48) | Standard Therapy (N=41) |
|---|
| CI=cardiac index, PAPm=mean pulmonary arterial pressure, PVR=pulmonary vascular resistance, SAPm=mean systemic arterial pressure, SV=stroke volume, TPR=total pulmonary resistance. |
| CI (L/min/m2) | 2.0 | 2.0 | 0.3 Denotes statistically significant difference between Epoprostenol and conventional therapy groups. | -0.1 |
| PAPm (mmHg) | 60 | 60 | -5 | 1 |
| PVR (Wood U) | 16 | 17 | -4 | 1 |
| SAPm (mmHg) | 89 | 91 | -4 | -3 |
| SV (mL/beat) | 44 | 43 | 6 | -1 |
| TPR (Wood U) | 20 | 21 | -5 | 1 |
These hemodynamic improvements appeared to persist when epoprostenol was administered for at least 36 months in an open, nonrandomized study.
Clinical Effects
Statistically significant improvement was observed in exercise capacity, as measured by the 6-minute walk test in patients receiving continuous intravenous epoprostenol plus conventional therapy (N=52) for 8 or 12 weeks compared to those receiving conventional therapy alone (N=54). Improvements were apparent as early as the first week of therapy. Increases in exercise capacity were accompanied by statistically significant improvement in dyspnea and fatigue, as measured by the Chronic Heart Failure Questionnaire and the Dyspnea Fatigue Index.
Survival was improved in NYHA functional Class III and Class IV patients with idiopathic or heritable PAH treated with epoprostenol for 12 weeks in a multicenter, open, randomized, parallel study. At the end of the treatment period, 8 of 40 (20%) patients receiving conventional therapy alone died, whereas none of the 41 patients receiving epoprostenol died (p=0.003).
Chronic Infusion in PAH/Scleroderma Spectrum of Diseases (SSD)
Hemodynamic Effects
Chronic continuous infusions of epoprostenol in patients with PAH/SSD were studied in a prospective, open, randomized trial of 12 weeks' duration comparing epoprostenol plus conventional therapy (N=56) to conventional therapy alone (N=55). Except for 5 NYHA functional Class II patients, all patients were either functional Class III or Class IV. Dosage of epoprostenol was determined as described in Dosage and Administration (2) and averaged 11.2 ng/kg/min at study's end. Conventional therapy varied among patients and included some or all of the following: anticoagulants in essentially all patients, supplemental oxygen and diuretics in two thirds of the patients, oral vasodilators in 40% of the patients, and digoxin in a third of the patients. A statistically significant increase in CI, and statistically significant decreases in PAPm, RAPm, PVR, and SAPm after 12 weeks of treatment were observed in patients who received epoprostenol chronically compared to those who did not. Table 12 illustrates the treatment-related hemodynamic changes in these patients after 12 weeks of treatment.
Table 12: Hemodynamics during Chronic Administration of Epoprostenol in Patients with PAH/SSD | Baseline | Mean Change from Baseline at 12 Weeks |
|---|
| Hemodynamic Parameter | Epoprostenol (N=56) | Conventional Therapy (N=55) | Epoprostenol (N=50) | Conventional Therapy (N=48) |
|---|
| CI=cardiac index, PAPm=mean pulmonary arterial pressure, RAPm=mean right atrial pressure, PVR=pulmonary vascular resistance, SAPm=mean systemic arterial pressure. |
| CI (L/min/m2) | 1.9 | 2.2 | 0.5 Denotes statistically significant difference between Epoprostenol and conventional therapy groups (N is the number of patients with hemodynamic data). | -0.1 |
| PAPm (mmHg) | 51 | 49 | -5 | 1 |
| RAPm (mmHg) | 13 | 11 | -1 | 1 |
| PVR (Wood U) | 14 | 11 | -5 | 1 |
| SAPm (mmHg) | 93 | 89 | -8 | -1 |
Clinical Effects
Statistically significant improvement was observed in exercise capacity, as measured by the 6-minute walk, in patients receiving continuous intravenous epoprostenol plus conventional therapy for 12 weeks compared to those receiving conventional therapy alone. Improvements were apparent in some patients at the end of the first week of therapy. Increases in exercise capacity were accompanied by statistically significant improvements in dyspnea and fatigue, as measured by the Borg Dyspnea Index and Dyspnea Fatigue Index. At week 12, NYHA functional class improved in 21 of 51 (41%) patients treated with epoprostenol compared to none of the 48 patients treated with conventional therapy alone. However, more patients in both treatment groups (28/51 [55%] with epoprostenol and 35/48 [73%] with conventional therapy alone) showed no change in functional class, and 2/51 (4%) with epoprostenol and 13/48 (27%) with conventional therapy alone worsened. Of the patients randomized, NYHA functional class data at 12 weeks were not available for 5 patients treated with epoprostenol and 7 patients treated with conventional therapy alone.
No statistical difference in survival over 12 weeks was observed in PAH/SSD patients treated with epoprostenol as compared to those receiving conventional therapy alone. At the end of the treatment period, 4 of 56 (7%) patients receiving epoprostenol died, whereas 5 of 55 (9%) patients receiving conventional therapy alone died.
No controlled clinical trials with epoprostenol have been performed in patients with pulmonary hypertension associated with other diseases.
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