We're building a better ClinicalTrials.gov. Check it out and tell us what you think!
Try the New Site
We're building a modernized ClinicalTrials.gov! Visit Beta.ClinicalTrials.gov to try the new functionality.
ClinicalTrials.gov Menu

A Study to Determine the Pharmacokinetic Profile, Safety and Tolerability of Sildenafil (REVATIO®) in Cardiac Surgery (Revaki-001)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT02136329
Recruitment Status : Completed
First Posted : May 13, 2014
Last Update Posted : January 30, 2020
British Heart Foundation
Information provided by (Responsible Party):
University of Leicester

Brief Summary:

The objectives of the study are the following:

  • To evaluate the pharmacokinetic profile of Sildenafil in cardiac surgery patients at risk of acute kidney injury
  • To determine the safety and tolerability of Sildenafil in cardiac surgery patients at risk of acute kidney injury

Condition or disease Intervention/treatment Phase
Acute Kidney Injury Drug: Sildenafil Phase 1

Detailed Description:

Acute kidney injury occurs in up to one third of all patients following cardiac surgery. It is manifested by an acute decline in kidney function and results in significant increases in postoperative complications as well as an almost fourfold increase in the risk of postoperative death. Our understanding of the underlying processes is poor and recent systematic reviews have concluded that there is no effective treatment.

Experimental studies have demonstrated that preservation of endogenous Nitric Oxide (NO) bioavailability is reno-protective in response to a variety of injurious stimuli. Endogenous NO activity is increased by administration of the phosphodiesterase type 5 (PDE-5) inhibitor sildenafil citrate. This is used clinically in the treatment of erectile dysfunction (Viagra®, Pfizer) and more recently, pulmonary hypertension and acute right ventricular failure (Revatio®, Pfizer). We have developed a preclinical swine model of extracorporeal circulation (cardiopulmonary bypass) mediated acute kidney injury that shows significant homology to that which occurs in post cardiac surgery patients. Administration of intravenous sildenafil prevents acute kidney injury in this model in association with an increase in NO bioavailability. There is a recognized clinical need for developing prevention and treatment strategies for AKI and results obtained in this preclinical study indicate that Sildenafil is suitable for further development as a potential prevention strategy for post cardiac surgery AKI.

Prior to conducting a safety and efficacy trial however we intend to first establish a dose of Sildenafil that is tolerated by cardiac surgery patients and compare the pharmacokinetics of this dose to the effective dose identified in our preclinical work. We therefore propose to evaluate the pharmacokinetic profile, safety and tolerability of sildenafil in 36 patients undergoing cardiac surgery, in an open label, dose escalation Phase I study. This study will inform the design of a subsequent randomized Phase IIb trial that will determine efficacy and safety

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 36 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: A Phase I Study to Determine the Pharmacokinetic Profile, Safety and Tolerability of Sildenafil (REVATIO®) in Cardiac Surgery
Study Start Date : June 2013
Actual Primary Completion Date : December 2014
Actual Study Completion Date : December 2014

Arm Intervention/treatment
Experimental: Sildenafil
All subjects in groups 1-6 will receive SIldenafil but in escalating doses.
Drug: Sildenafil

The active study drug, Revatio®, is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type-5 (PDE5). Sildenafil citrate is designated chemically as 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4,3-d] pyrimidin-5-yl)-4-ethoxyphenyl] sulfonyl]-4-methylpiperazine citrate.

The active study medication is supplied in single use glass vials and as a clear, colourless, sterile, ready-to-use solution containing 10 mg (12.5 mL) of sildenafil. Each mL of solution contains 1.124 mg sildenafil citrate, 50.5 mg dextrose and water for injection.

Sildenafil is manufactured under Good Manufacturing Practice (EU-GMP) by Pfizer Inc

Other Name: REVATIO®

Primary Outcome Measures :
  1. Area under the plasma concentration versus time curve and Plasma Concentration of Sildenafil [ Time Frame: 48 Hours ]
    There will be Pharmacokinetic sample collection pre and post dose to look at plasma concentration of sildenafil. Sample collection timepoints are post dose at 10 mins, 15 mins, 30 mns, 45 mins 2 hours, 4 hours, 12 hours, 24 hours and 48 hours.

Secondary Outcome Measures :
  1. Serum creatinine and Biochemical markers of AKI [ Time Frame: 5 Days ]

    Serum creatinine measured from blood samples collected pre-operatively and at 6 hours, 24 hours, 48 hours and 96 hours after the operation.

    Biochemical markers of acute kidney injury measured in urine pre-operatively, 0mins, 6 houts, 24 hours and 48 hours.

Other Outcome Measures:
  1. Adverse Events [ Time Frame: 6 Weeks ]
    Adverse Events will be captured from from time of consent to 6 weeks post operation

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Adult cardiac surgery patients (>18 years) undergoing cardiac surgery with moderately hypothermic CPB (32-34°C) and blood cardioplegia
  2. Identified as representing a high risk group for acute kidney injury using a modified risk score based on the variables of Age, Sex, BMI, Smoking Status, NHYA class, Previous Operations, Peripheral Vascular Disease, Diabetes, Hypertension, Pre-operative Haemoglobin level, Pre-operative eGFR, Operative Priority, Operation Type, Ejection Fraction and Presence of Pre-Operative Critical Events.
  3. Female subjects of childbearing potential are not to be pregnant (to be confirmed by urine human chorionic gonadotropin pregnancy test prior to dosing). Women are considered not to be of childbearing potential if they have been surgically sterilised (eg, tubal ligation, oophorectomy or hysterectomy) or are postmenopausal (defined as serum follicle-stimulating hormone level of ≥30 IU/mL) in the absence of hormone replacement therapy and complete absence of menses for at least 24 consecutive months.

Exclusion Criteria:

  1. Emergency or salvage procedure
  2. Ejection fraction <30%
  3. CKD Stage 5, defined as eGFR<15ml/min or renal replacement therapy.
  4. Administration of potent CYP 3A4 inhibitors within 1 month prior to study participation (e.g. HIV protease inhibitors, imidazole antifungals and erythromycin, please see Appendix 1 for a full list of prohibited medications).
  5. Administration of nitrate medicines (e.g. glyceryl trinitrate within 24 hours of surgery.
  6. Any ongoing malignancy, or prior malignancy that currently requires treatment.
  7. Patients allergic to any other PDE-5 Inhibitor
  8. Patients who are participating in another interventional clinical study


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02136329

Layout table for location information
United Kingdom
Department of Cardiovascular Sciences.
Leicester, Leicestershire, United Kingdom, LE3 9QP
Sponsors and Collaborators
University of Leicester
British Heart Foundation
Layout table for investigator information
Principal Investigator: Gavin Murphy, Prof University of Leicester
Layout table for additonal information
Responsible Party: University of Leicester
ClinicalTrials.gov Identifier: NCT02136329    
Other Study ID Numbers: 0359
First Posted: May 13, 2014    Key Record Dates
Last Update Posted: January 30, 2020
Last Verified: December 2014
Additional relevant MeSH terms:
Layout table for MeSH terms
Acute Kidney Injury
Renal Insufficiency
Kidney Diseases
Urologic Diseases
Female Urogenital Diseases
Female Urogenital Diseases and Pregnancy Complications
Urogenital Diseases
Male Urogenital Diseases
Sildenafil Citrate
Vasodilator Agents
Phosphodiesterase 5 Inhibitors
Phosphodiesterase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Urological Agents