Clinical pharmacology and efficacy of inhaled iloprost for the treatment of pulmonary arterial hypertension

Similar to other prostanoids, iloprost is a potent vasodilator with considerable antiproliferative and anti-thrombotic properties, although the relevance of its ability to affect platelet aggregation in this subset of patients is unrecognized. The pathogenesis of pulmonary arterial hypertension (PAH) is a multifactorial and complex process secondary to an innate deficiency of substances that induce vasodilation and an overproduction of substances producing vasoconstriction. The production of endothelial vasoactive mediators such as nitric oxide, prostacyclin, endothelin-1, thromboxane and serotonin affect the growth of smooth muscle cells, which facilitate the development of structural remodeling changes that are characteristic of PAH. There have been remarkable advances in understanding the pathologic processes that are responsible for increasing pulmonary vascular resistance and that result in elevated pulmonary artery pressures in order to reverse and prevent progression of the disease process. The goals of treatment in these patients are to alleviate the patients' symptoms, to improve functional capacity and to prevent the progression of the disease. The prostacyclin analogs, such as iloprost, have given hope to these patients who struggle under the burdens of this complex disease.