Absorption behavior of riociguat: bioavailability, food effects, and dose-proportionality

Background Riociguat, an oral soluble guanylate cyclase (sGC) stimulator, is currently being investigated for the treatment of pulmonary hypertension. Riociguat has a novel dual mode of action, directly stimulating sGC, independent of nitric oxide (NO), and increasing sensitivity of sGC to NO. Riociguat thereby restores the NO–sGC– cGMP pathway, which is impaired in pulmonary hypertension. Three pharmacokinetic studies were performed to characterize the absorption behavior of riociguat including absolute bioavailability, food effects, and dose-proportionality.