Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration of riociguat with anticoagulant, antiplatelet, or other antithrombotic therapy may increase the risk of bleeding. Patients with pulmonary hypertension have an underlying risk for respiratory tract bleeding, which can be further exacerbated by riociguat and use of antithrombotic agents, particularly in the presence of additional risk factors such as recent episodes of serious hemoptysis (including those managed by bronchial arterial embolization) or concomitant prostacyclin use (e.g., epoprostenol, iloprost, and treprostinil) due to their inhibitory effect on platelet aggregation. In clinical trials, serious bleeding occurred in 2.4% and hemoptysis in 1% of patients taking riociguat compared to 0% of placebo patients. The proposed mechanism for the bleeding risk associated with riociguat is unknown. However, an in vitro study indicates that riociguat may inhibit von Willebrand factor elongation and platelet adhesion on the surface of pulmonary artery endothelial cells.

MANAGEMENT: Bleeding risk should be carefully evaluated before initiating riociguat in patients on antithrombotic therapy. Close clinical and laboratory monitoring for bleeding complications is recommended if concomitant use is required. Some authorities recommend avoiding riociguat in patients with a history of serious hemoptysis or who have previously undergone bronchial arterial embolization.

Chemical substances present in cigarette smoke may reduce the blood levels of riociguat. This means that the medication may be less effective if you smoke during treatment. Let your doctor know if you are a smoker, or if you start smoking or stop smoking during treatment with riociguat, because the dosage may need to be adjusted. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Food may affect the absorption and blood levels of riociguat. To avoid significant fluctuations in blood levels of the medication, riociguat should be taken about the same time each day consistently either with or without food.