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

"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"