known allergy against Benzbromaron, Gelborange S or other ingredient of the used drug (Benzbromarone AL) or a drug with similar chemical structure

severe renal insufficiency (GFR\<30ml/min/kg)

renal diathesis

severe hepatic disease (Bilirubin \>1.6 mg% or AST or ALT \> 3x Norm)

known pregnancy

uncontrolled systemic arterial hypertension (\>150 mmHg systolic or 95 mmHg diastolic)

uncontrolled ventricular arrythmia

uncontrolled bradycardic or tachycardic supraventricular arrythmia

myocardiac infarction within the last 12 months

pulmonary embolism within the last 6 months

ongoing iv. or sc. Prostanoid therapy for PAH

Pulmonary hypertension other than PAH

Acute Effects of Benzbromaron on the Pulmonary Circulation