BACKGROUND Favorable results of treatment with bosentan in patients with Eisenmenger syndrome are available. However, data in Down patients are lacking. In this study, we evaluate the therapeutic role of bosentan treatment in Down patients with Eisenmenger syndrome. METHODS In this open-label study, 24 Down patients (>18 years) with Eisenmenger syndrome (17 males) were treated with bosentan. ...

BACKGROUND Endothelin-1 is a potent vasoconstrictor and smooth-muscle mitogen. In a preliminary study, the orally administered dual endothelin-receptor antagonist bosentan improved exercise capacity and cardiopulmonary hemodynamics in patients with pulmonary arterial hypertension. The present trial investigated the effect of bosentan on exercise capacity in a larger number of patients and compa...

Bile acid accumulation in hepatocytes due to inhibition of the canalicular bile salt export pump (BSEP/ABCB11) has been proposed as a mechanism for bosentan-induced hepatotoxicity. The observation that bosentan does not induce hepatotoxicity in rats, although bosentan has been reported to inhibit rat Bsep and cause elevated serum bile acids, challenges this mechanism. The lack of hepatotoxicity...

Bosentan is a competitive inhibitor of endothelin receptors. In vitro, bosentan potently inhibits binding of endothelin-1 to human ET-A and ET-B receptors. Potency on ET-A receptors was only slightly greater than potency on ET-B receptors. Functionally, bosentan inhibits contractile effects of endothelin-1 in rat aorta and human blood internal mammary artery and vein. Oral administration of bos...

Bosentan, an endothelin-1 (ET) receptor antagonist is an important drug for the effective management of patients with pulmonary arterial hypertension. Bosentan has a rather complicated pharmacokinetics in humans involving multiple physiological components that have a profound influence on its drug disposition. Bosentan is mainly metabolized by cytochrome P450 (CYP) 3A4 and 2C9 enzymes with the ...

BACKGROUND We aimed to investigate the extent of pharmacokinetic drug interactions between bosentan and a fixed combination of lopinavir/ritonavir. METHODS This was a three-way crossover study in 12 healthy male participants treated with bosentan (125 mg twice daily) and lopinavir/ritonavir (400/100 mg twice daily) alone or in combination for 9.5 days. RESULTS Combination treatment resulted...

Recurrent digital ulcers are manifestations of vascular disease in patients with systemic sclerosis (SSc). We report six patients with severe digital ulcers who were treated with bosentan administered p.o., 62.5-125 mg daily. The mean duration from the diagnosis of SSc to the initiation of bosentan was 9.5 years, and the observation period after bosentan administration was from 7 months to 4.5 ...

Endothelin (ET) receptor antagonism protects from ischemia-reperfusion injury. We hypothesized that the cardioprotective effect is related to nitric oxide (NO) bioavailability. Buffer-perfused rat and mouse hearts were subjected to ischemia and reperfusion. At the onset of ischemia, the rat hearts received vehicle, the dual endothelin type A/type B (ETA/ETB) receptor antagonist bosentan (10 mic...

PURPOSE Bosentan is a drug currently taken orally for the treatment of pulmonary arterial hypertension. However, the water solubility of bosentan is very low, resulting in low bioavailability. The aim of this study was preparation and optimization of bosentan nanosuspension to improve solubility and dissolution rate. METHODS The different formulations designed by Design Expert® software. Nano...