Riociguat: a review of its use in patients with chronic thromboembolic pulmonary hypertension or pulmonary arterial hypertension.

Riociguat (Adempas(®)), a soluble guanylate cyclase stimulator, is a new, first-in-class drug approved for the treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) [inoperable or persistent/recurrent following surgery] or pulmonary arterial hypertension (PAH). It has been designated an orphan medicine by the European Medicines Agency and the US FDA. This article reviews the available pharmacological properties of oral riociguat and its clinical efficacy and tolerability in adults with CTEPH or PAH. Riociguat is effective and well tolerated in patients with inoperable CTEPH or persistent/recurrent CTEPH following pulmonary endarterectomy, and in patients with PAH. It has a positive result on exercise capacity and pulmonary haemodynamics, and improves WHO functional class. Most adverse events can be attributed to the vasodilatory mechanism of riociguat; however, there is a potential for serious bleeding and fetal harm, and riociguat use is contraindicated in pregnant patients. Pulmonary endarterectomy remains the first treatment of choice for CTEPH, as it is potentially curative. Head-to-head trials comparing riociguat with the approved phosphodiesterase type 5 inhibitors in patients with PAH would be of value for the placement of riociguat in the management of this disease. Riociguat is a promising addition to the treatment options for patients with CTEPH or PAH.