Riociguat, a guanylate cyclase stimulator for the treatment of pulmonary hypertension

Pulmonary hypertension (PH) is a rare disease and it is classified into five major categories as per WHO classification. Pulmonary arterial hypertension (category 1) is the increased resistance of pulmonary vasculature due to familial; idiopathic or associated with other connective tissue disorders. The medical therapy forms the major treatment of pulmonary arterial hypertension and inoperable chronic thromboembolic pulmonary hypertension (category 4). Despite the medical therapy available the prognosis remains poor and there is a need for new drugs with novel mechanism of action. Riociguat is an oral guanylate cyclase stimulator with dual mechanism of action recently approved for pulmonary hypertension. The clinical trials have shown that the drug is efficacious in improving 6 minute walking distance and other hemodynamic parameters. The drug was efficacious at doses of 1-2.5 mg and it was well tolerated in most of the patients. The adverse effects observed were hypotension, head ache, dizziness, vomiting.