Tratamiento farmacológico de la hipertensión portal

RESUMO

Variceal bleeding is the most lethal complication of portal hypertension. Recent estimates have shown worldwide 50 million people with this entity, of which 60 percent have varices at the time of diagnosis and 20 percent bleeds each year. The mortality of each bleeding episode approaches 50 percent, the rate of recurrence in the first year after the initial hemorrhage is 60 percent and even higher in the first six weeks after bleeding. Treatment of portal hypertension must include the following aspects 1)Treatment of active bleeding, 2)Prevention of recurrence and 3)Prevention of the first bleeding episode. Variceal bleeding never occurs with portal pressure below 12 mmHg, which means that although portal pressure is only one of the factors that determines the incidence of bleeding, reduction of portal pressure is the goal of the treatment. Pharmacologic treatment is based on vasoactive drugs that decrease portal pressure by a reduction of the blood flow that reaches the portal circulation (splanchnic vasoconstrictors), or through a reduction of the portal vein resistance (venodilators). Many drugs can reduce portal pressure, but few have received clinical evaluation. Vasopressin and somatostatin have been used successfully in the treatment of active variceal bleeding, the latter has shown absence of significant cardiovascular side effects commonly seen with the former. Addition of nitrates have increased the positive effects of vasopressin with a salutary reduction of side effects. Non selective batablockers such as propanolol and other compounds have been proved effective by several controlled studies and recent metaanalysis in the control of the recurrence of bleeding and the initial bleeding episode.