Pulmonary hypertension is a severe cardiovascular disorder characterized by abnormally elevated pulmonary arterial pressure. The disease often progresses insidiously and is associated with a poor prognosis, significantly impairing patients’ exercise capacity and quality of life.
Riociguat tablets, as a novel targeted therapeutic agent, offer a new treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH) through a unique mechanism of action. DengyueMed provides a comprehensive overview of the clinical value and appropriate use of riociguat, covering its mechanism of action, approved indications, and clinical application.

Unique Mechanism of Action: Dual Activation of Soluble Guanylate Cyclase

The primary pharmacological target of riociguat is soluble guanylate cyclase (sGC), a key signaling molecule widely expressed in vascular smooth muscle cells and essential for the regulation of vasodilation. Unlike conventional therapies, riociguat features a dual mode of action, combining both nitric oxide (NO)–dependent and NO–independent mechanisms.

On one hand, riociguat stabilizes the binding of endogenous NO to sGC, significantly enhancing the sensitivity of sGC to NO and amplifying NO-mediated vasodilatory effects. On the other hand, riociguat can directly bind to a specific site on sGC and stimulate its activity independently of NO, thereby promoting the production of cyclic guanosine monophosphate (cGMP).

As a critical intracellular second messenger, cGMP effectively relaxes pulmonary vascular smooth muscle, reduces vascular resistance, and exerts anti-proliferative, anti-fibrotic, and anti-inflammatory effects. Through these multi-dimensional actions, riociguat improves pulmonary vascular remodeling, lowers pulmonary arterial pressure, and ultimately enhances cardiac function and exercise tolerance in patients.

Clearly Defined Indications: Addressing Two Major Forms of Pulmonary Hypertension

Riociguat tablets are currently the only targeted therapy in China approved for both CTEPH and PAH. Their efficacy and safety have been validated in multiple clinical trials, with indications specifically limited to adult patients classified as WHO functional class II–III.

In the treatment of CTEPH, riociguat is indicated in two clinical scenarios:

1. patients with persistent or recurrent pulmonary hypertension following pulmonary endarterectomy, and

2. patients who are not eligible for surgical intervention due to complex disease characteristics or physical limitations.
   The primary therapeutic goals in these populations are to improve exercise capacity and slow disease progression.

In PAH, riociguat may be used as monotherapy or in combination with endothelin receptor antagonists or prostacyclin analogues. Pivotal clinical trials primarily enrolled patients with idiopathic or heritable PAH, as well as PAH associated with connective tissue diseases, demonstrating significant improvements in exercise tolerance and WHO functional class.

Conclusion and Outlook

With its distinctive dual activation mechanism and clearly defined dual indications, riociguat tablets represent an important therapeutic option for patients with CTEPH and PAH, particularly in improving exercise capacity and delaying disease progression. However, strict adherence to dosing and administration guidelines is essential. Individualized dose titration, careful management of contraindications, and monitoring of adverse events are critical to ensuring safe and effective treatment.

The approval and market availability of domestically manufactured riociguat tablets have further improved drug accessibility, offering renewed hope to a broader population of patients with pulmonary hypertension. Looking ahead, continued accumulation of real-world evidence and optimization of dosing strategies will be essential to maximize the clinical benefits of this targeted therapy and further improve patient outcomes.