In a new study, scientists have established that sildenafil, a drug also sold as Viagra and known for treating erectile dysfunction (male impotence) and pulmonary arterial hypertension (PAH), does not influence blood flow in patients with cirrhosis.
Erectile dysfunction is a common problem affecting about half of all patients with end-stage liver disease.
The scientists found that sildenafil had no effect on the hepatic venous pressure gradient (HVPG).
In the study, the scientists aimed at finding if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis.
The study was conducted on ten patients with biopsy proven cirrhosis and an HVPG above 12 mmHg.
The scientists then measured the splanchnic blood flow and the HVPG during liver vein catheterization before and 80 min after oral administration of 50 mg sildenafil.
Blood flow was estimated by use of indocyanine green clearance technique and Fick's principle, with correction for non-steady state.
Though the scientists saw a decrease in arterial blood pressure80 min after administration of the phosphodiesterase type-5 inhibitor sildenafil, they were unable to demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG.
It was known that selective phosphodiesterase type-5 inhibitors, such as sildenafil, represent an important advance in management of erectile dysfunction.
Scientists measured the HVPG and the estimation of splanchnic blood flow of the participants before and 80 min after oral administration of 50 mg of sildenafil.
This study reports the effects of sildenafil on the splanchnic hemodynamics in patients with biopsy proven cirrhosis and manifest portal hypertension.
Despite a small decrease in mean arterial pressure, the main finding in this study was that the splanchnic blood flow, oxygen consumption and the mean HVPG did not change 80 min after administration of sildenafil, i.e. at a time-point when a therapeutic plasma concentration of sildenafil could be documented.
The study shows that sildenafil does not induce any profound clinically relevant changes in splanchnic blood flow, oxygen consumption and HVPG.
The authors concluded that phosphodiesterase type-5 inhibition is of no use as a therapeutic agent for alleviating portal hypertension in patients with chronic end-stage liver disease.