Acute Effects of Benzbromaron on the Pulmonary Circulation


Actual studies suggest that a calcium activated chlorid channel (TMEM16A) may play a relevant role in the pathogenesis of pulmonary arterial hypertension (PAH). The inhibition of this channel led to pulmonary vasorelaxation in preclinical studies. Benzbromarone is a well known inhibitor of the TMEM16A channel and is used in patients with gout.

In this pilot study the investigators plan to investigate if Benzbromarone has an acute effect on the pulmonary arteries in humans. This will be investigated within the frame of a right heart catheterization performed in patients with known PAH due to clinical reasons. The investigators hypothesize that the application of Benzbromarone leads to pulmonary vasodilation, which can be recognized by the decrease in pulmonary vascular resistance. In addition, the change in pulmonary and systemic arterial pressure, pulmonary arterial wedge pressure, heart rate and arterial oxygen saturation will be assessed. Due to clinical reasons patients will receive NO (15 ppm) during right heart catheterization. Hemodynamic changes upon NO and Benzbromarone may be compared.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: August 2016


  • Drug: Benzbromarone
    • 1x200mg Benzbromarone will be applied after baseline measurements during right heart catheterization. The effects of the drug on the pulmonary hemodynamics will be assessed after 2 hours.

Arms, Groups and Cohorts

  • Experimental: Benzbromarone
    • 1x200mg Benzbromarone

Clinical Trial Outcome Measures

Primary Measures

  • Pulmonary vascular resistance (Wood units) assessed by right heart catheterization
    • Time Frame: 2 hours

Secondary Measures

  • Mean pulmonary arterial pressure (mmHg) assessed by right heart catheterization
    • Time Frame: 2 hours
  • Mean systemic arterial pressure (mmHg) assessed by sphygmomanometer
    • Time Frame: 2 hours
  • arterial oxygen saturation 8%) assessed by arterial blood gas analysis
    • Time Frame: 2 hours

Participating in This Clinical Trial

Inclusion Criteria

  • written informed consent
  • known pulmonary arterial hypertension
  • right heart catheterization indicated due to clinical reasons

Exclusion Criteria

  • 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

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Medical University of Graz
  • Collaborator
    • Ludwig Boltzmann Institute Lung Vascular Research
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Horst Olschewski, MD, Principal Investigator, Medical University of Graz

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