Prostacyclins in PH
The intravenous prostacyclins have the greatest efficacy as treatments for PH and are often effective in patients who have failed all other treatments. Favourable properties include vasodilation, platelet inhibition, inhibition of vascular smooth-muscle growth, and inotropic effects. Prostacyclins epoprostenol (Flolan®), treprostinil (Remodulin®) and iloprost (Ventavis®) are indicated for PH.
Epoprostenol (prostaglandin PGI2 or prostacyclin) is administered intravenously and requires placement of a permanent central venous catheter and infusion through an ambulatory infusion pump system. Side effects include flushing, jaw pain, and diarrhea, which are generally tolerated by most patients.
Treprostinil, an analogue of epoprostenol, and has a longer half-life than epoprostenol (4h), and may be given intravenously or subcutaneously through a small infusion pump. The major problem with the subcutaneous administration has been local pain at the infusion site, which has caused many patients to discontinue therapy. Side effects are similar to those seen with epoprostenol.
Iloprost, also a prostacyclin analogue, is administered via inhalation, which results in less systemic side effects. It has been shown to improve symptoms and exercise tolerance. The most common side effects are flushing and cough. Because of the very short half-life (<30 min) it is recommended to administer treatments as often as every 2h.
EPAR of iloprost.