Udenafil

(Dosing Study)

Study Summary

Udenafil is a medication used to treat erectile dysfunction in adult men. It belongs to a class of drugs thought to be effective in improving heart performance in patients with pulmonary hypertension and heart muscle dysfunction. As a potential therapy for individuals after the Fontan surgery, this study tested different doses of udenafil for safety and possible benefit.

This is the first udenafil study in children or teens that have had Fontan surgery. It is important to determine which dose of udenafil is best. This study enrolled 36 patients and identified the best dose to use for the FUEL Trial.


36 Patients

36 patients were enrolled in this study.

87.5 mg Dosing

The 87.5 mg twice each day dose achieved the highest plasma drug level and was associated with a suggestion of improvement in myocardial performance.

Additional Research Needed

The FUEL Trial was designed to continue to evaluate the use of udenafil in hundreds of participants after Fontan surgery.

Who was in the study?

Males and females ages 14-18 years of age with Fontan physiology who agreed to participate in the study were enrolled.

What happened during the study?

Study participants took oral Udenafil at different dose levels for five days and completed the following assessments:
  • Medical Record Review: for information about surgeries, tests, hospitalizations, medications and services received such as physical or speech therapy.
  • Exercise Testing: to evaluate heart function during exercise. Study participants were asked to pedal on a stationary bike while various measurements of breathing, heart rate and blood pressure were taken.
  • Vascular Function Test (also called an EndoPAT): to assess function of blood vessels.
  • Echocardiograms and blood samples were also done.

What were the results of the study?

Udenafil was well-tolerated at all dosing levels. The 87.5 mg twice daily cohort achieved the highest plasma drug level and was associated with a suggestion of improvement in myocardial performance. The FUEL Trial was designed with this dosage, to continue to evaluate udenafil in hundreds of participants after Fontan surgery.

Study Publications

  • Results of a phase I/II multi-center investigation of udenafil in adolescents after fontan palliation

    D. Goldberg, Am Heart J. 2017; 188:42-52.

    The purpose of this study was to identify a safe dose of udenafil in teens with single ventricle heart disease. The participants were assigned to placebo or once-a-day or twice-a-day dosing, at different strengths. The 87.5 mg twice-a-day dosing regimen was well tolerated and showed the most consistent drug levels in the blood. This dose was used for the phase III FUEL (Fontan Udenafil Exercise Longitudinal) clinical trial.

    Read Publication