Organic nitrates in portal hypertension.

In conclusion, chronic administration of organic nitrates, allowing for a nitrate-free interval each day, to cirrhotic patients reduces portal pressure with a variable, dose-dependent effect on azygos blood flow. The mechanisms of portal pressure reduction may vary according to the different doses and severity of liver disease. No studies to date have used dose-titration to determine the optimal beneficial effects in an individual patient, but some have at least compared the effect of different doses. Perhaps an end-point of mean arterial blood pressure reduction to 70 mm Hg could be suggested for future studies. The prophylactic benefit of nitrates for variceal bleeding still remains to be tested by controlled clinical trials. However, several problems in this evaluation need to be addressed, including patient compliance, selection of responders, evaluation of treatment, dose, and the duration of treatment. In contrast to the diminished expectations of propranolol for the prevention of rebleeding, there is mounting evidence of a major role for nitrates.