Products
Riociguat is commercially available in the form of film-coated tablets (Adempas). It was approved in many countries in 2013. Riociguat is the first active ingredient from this group of drugs.
Structure and properties
Riociguat (C20H19FN8O2, Mr = 422.4 g/mol) exists as a white to yellow, crystalline, non-hygroscopic substance that is sparingly soluble in water.
Effects
Riociguat (ATC C01DX) has vasodilatory, antihypertensive, and antiproliferative properties. It enhances nitric oxide (NO) binding to soluble guanylate cyclase (sGC) and additionally stimulates guanylate cyclase directly, independently of NO. This leads to increased formation of cGMP in vascular smooth muscle.
Indications
- Chronic thromboembolic pulmonary hypertension (CTEPH).
- Pulmonary arterial hypertension (PAH, not in all countries).
Dosage
According to the professional information. The tablets are taken three times a day, regardless of meals. The dose is slowly increased at intervals of two weeks each and adjusted individually.
Contraindications
- Hypersensitivity
- Pregnancy and lactation
- Combination with certain other medications
Full details of precautions and interactions can be found in the drug label.
Interactions
Riociguat is metabolized by CYP450 isoenzymes (CYP1A1, CYP3A4, CYP2C8, CYP2J2) and is a substrate of P-glycoprotein and BCRP. Corresponding pharmacokinetic drug-drug interactions are possible. Concomitant administration of nitrates, NO donors, phosphodiesterase-5 inhibitors, and nonspecific phosphodiesterase inhibitors is contraindicated because they potentiate the effects and adverse effects of riociguat.
Adverse Effects
The most common possible adverse effects include headache, dizziness, dyspepsia, peripheral edema, low blood pressure, and nausea. Riociguat may increase the risk of bleeding.
