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

Pulmonary hypertension (PH) is a rare disease and it is classifi ed into fi ve major categories as per WHO classifi cation. Pulmonary arterial hypertension (PAH) (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 PAH and inoperable chronic thromboembolic PH (Category 4). Despite the medical therapy available the prognosis remains poor and there is a need for new drugs with a novel mechanism of action. Riociguat is an oral guanylate cyclase stimulator with dual mechanism of action recently approved for PH. The clinical trials have shown that the drug is effi cacious in improving 6 min walking distance and other hemodynamic parameters. The drug was effi cacious at doses of 1-2.5 mg and it was well tolerated in most of the patients. Observed adverse effects were hypotension, head ache, dizziness, and vomiting.