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Drug & research development » Clinical trials » NCT02057458

Blood Flow and Vascular Function in Cystic Fibrosis (CF-FLOW)

Official title: Role of Blood Flow and Vascular Function on Exercise Capacity in Cystic Fibrosis

Clinical Trials gov number: NCT02057458

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Purpose: To look at how blood flow and artery function contribute to exercise capacity in CF.

Phase: 2

Type: Interventional, randomized, double-blind, crossover

Study sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

  • Diagnosis of CF and healthy controls
  • Men and women (greater than 18 yrs. old)
  • Resting oxygen saturation (room air) >90%
  • Forced expiratory volume (FEV1) percent predicted >30%
  • Patients with or without CF related diabetes
  • Traditional CF-treatment medications
  • Ability to perform reliable/reproducible pulmonary function tests (PFT)
  • Clinically stable for 2 weeks (no exacerbations or need for antibiotic treatment within 2 weeks of testing or major change in medical status)


Geographical Location
United States

Number of Participants
≤50 (≥18 years)

Primary Endpoint

Exercise capacity (within 1 h after injection and after taking sildenafil three times daily for four weeks)

Secondary Endpoint

At 1 h and 4 weeks

  • Flow-mediated dilation
  • Arterial stiffness evaluation
  • Physio flow

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  • Experimental: Acute (1 hour) Sildenafil & Placebo

In randomized order, on two separate days, exercise capacity and endothelial function will be determined 1 hour following a single dose of either sildenafil (50 mg) or placebo (sugar pill designed to mimic the sildenafil treatment)

  • Experimental: Sub Chronic (4 weeks) Sildenafil

Following the acute study, patients will be instructed to take 20 mg of sildenafil, three times a day, for 4 weeks. Exercise capacity and endothelial function will be determined within 48 hours following the last dose.

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