From the FDA Drug Label
Adverse events which may be related to the underlying disease include dyspnea, fatigue, chest pain, edema, hypoxia, right ventricular failure, and pallor.
- The incidence of hypoxia in Pulmonary Pulmonary Arterial Hypertension (PPAH) is not directly stated in the provided drug label.
- Hypoxia is listed as an adverse event that may be related to the underlying disease, but no specific incidence is provided 1.
From the Research
Hypoxia is a common complication in patients with primary pulmonary arterial hypertension (PPAH), occurring in approximately 10-20% of patients, as reported in a recent study 2. The incidence of hypoxia in PPAH can increase with disease progression, with nearly all patients experiencing some degree of hypoxemia in advanced stages. Hypoxia in PPAH results from:
- Ventilation-perfusion mismatch
- Reduced cardiac output
- Right-to-left shunting through a patent foramen ovale if present Patients with PPAH should have regular oxygen saturation monitoring, with supplemental oxygen therapy recommended when SpO2 falls below 90% or PaO2 is less than 60 mmHg, as suggested by a study on the use of supplemental oxygen in patients with pulmonary arterial hypertension 3. Oxygen therapy should be titrated to maintain SpO2 above 90% at rest, during sleep, and with exertion, typically starting at 2-4 L/min via nasal cannula and adjusting as needed. The physiological basis for hypoxia in PPAH involves impaired gas exchange due to pulmonary vascular remodeling, reduced pulmonary blood flow to well-ventilated areas, and increased pulmonary pressures leading to fluid accumulation in the lungs. Early recognition and treatment of hypoxia is essential as chronic hypoxemia can worsen pulmonary hypertension through hypoxic pulmonary vasoconstriction, creating a detrimental cycle of disease progression, as discussed in a review of the diagnosis and treatment of pulmonary arterial hypertension 4. Key points to consider in the management of hypoxia in PPAH include:
- Regular oxygen saturation monitoring
- Supplemental oxygen therapy as needed
- Titration of oxygen therapy to maintain SpO2 above 90%
- Early recognition and treatment of hypoxia to prevent disease progression.