Review: pharmacotherapeutic agents in the treatment of portal hypertension

Drug therapies in liver disease

The likelihood of a general physician encountering a patient with compensated and decompensated liver disease is increasing. This article provides an overview of pharmaceutical agents currently used in the management of cirrhosis and is designed to allow a better understanding of the rationale for using certain drugs in patients with often complex pathology.

Inhibition of glucagon improves splanchnic hyporesponse to terlipressin in cirrhotic rats with blood retention in the gastric lumen

BACKGROUND/AIMS

Portal hypotensive effect of terlipressin is less effective when given during hemorrhage than in stable state. Blood retention in the stomach can induce splanchnic hyperemia which is mainly a consequence of an increased glucagon release. This study was undertaken to evaluate whether gastric blood retention contributes to the splanchnic hyporesponse to terlipressin.

METHODS

Plasma glucagon determination was performed under basal conditions and after intragastric blood gavage in sham-operated and cirrhotic rats. Additionally, splanchnic hemodynamic effects to terlipressin were measured in blood-gavaged cirrhotic rats with or without glucagon antiserum or octreotide infusion. Another set of air-gavaged cirrhotic rats was included for comparison.

RESULTS

Plasma glucagon level increased in both sham-operated and cirrhotic rats following blood gavage. Compared to air-gavaged cirrhotic rats, splanchnic hyporesponse to terlipressin was observed in cirrhotic rats receiving intragastric blood gavage. However, this splanchnic hyporesponse to terlipressin in blood-gavaged cirrhotic rats was overcome by glucagon antiserum or octreotide infusion.

CONCLUSIONS

Intragastric blood gavage induced an elevation of plasma glucagon level and led to a splanchnic hyporesponse to terlipressin. Glucagon antiserum or octreotide administration overcame this hyporesponse. Excessive release of circulating glucagon may be an important factor for splanchnic hyporesponse to terlipressin in cirrhotic portal hypertension during hemorrhage.

Pharmacologic efficacy in gastric variceal rebleeding and survival: including multivariate analysis

BACKGROUND

Therapy with beta-blocker and nitrate has been reported to improve survival of patients with bleeding esophageal varices and to decrease esophageal rebleeding. However, there is little information available concerning the efficacy of these medications on rebleeding risk and survival in gastric variceal bleeding after initial hemostasis.

METHODS

We conducted an open trial to observe the roles of beta-blocker and nitrate in the long-term outcome of bleeding gastric varices. Eighty-three patients were included and evaluated on the basis of age, gender, gastric variceal size, associated esophageal variceal size, Child-Pugh classification, existence of hepatoma and portal vein thrombosis, beta-blocker or nitrate therapy, and follow-up histoacryl injection. Survival analysis and multivariate analysis with the Cox proportional hazards model were performed to evaluate independent risk factors.

RESULTS

Larger gastric varices have been shown to be the only risk factor for rebleeding (adjusted odds ratio, 4.50; 95% CI, 1.30-15.59). beta-Blocker and nitrate did not significantly reduce the incidence of rebleeding (adjusted odds ratio, 0.37; 95% CI, 0.08-1.66). Although medical treatment was shown to improve the overall survival by Kaplan-Meier method (p < 0.01), multivariate analysis showed Child-Pugh class B or C and advanced hepatoma with portal vein thrombosis to be the real independent risk factors that influence survival (Child-Pugh class B or C odds ratio, 2.72; 95% CI, 1.53-4.84; portal vein thrombosis odds ratio, 6.99; 95% CI, 2.42-20.16). beta-Blocker and nitrate did not significantly prolong survival independently.

CONCLUSIONS

beta-Blocker and nitrate did not decrease the risk of rebleeding and did not improve the overall survival independently. The poor prognosis was correlated with Child-Pugh class B or C, and the advance hepatoma, with portal vein thrombosis.

Oesophageal varices: assessment of the risk of bleeding and mortality

Patients with oesophageal varices run a high risk of bleeding and even death, however rates of bleeding and mortality vary greatly. Indeed, a number of patients with varices never bleed. Prophylactic therapy is effective, but can be associated with side-effects. It remains to be determined which patients are at high risk of bleeding and require treatment. In addition, since non-response to medical therapy has been reported to occur in 20-40% of patients, the effect of a given prophylactic drug, or combinations of drugs, needs to be tested. A review is given of available methods of assessment. The Hepatic Venous Pressure Gradient, and measurements of the variceal pressure, are two proven methods, and the latter has the advantages of being non-invasive and having value in presinusoidal portal hypertension.

Acute and chronic haemodynamic and renal effects of carvedilol in patients with cirrhosis

BACKGROUND/AIMS

Recent reports have suggested that the vasodilating beta-blocker carvedilol may have beneficial acute haemodynamic effects in cirrhotic portal hypertension. However, no data exist on chronic use or renal effects in this patient group. The aim of this study was to assess the acute and chronic haemodynamic and renal effects of carvedilol in cirrhotic patients.

METHODS

Seventeen cirrhotic patients (mean age 55.2+/-2.8, mean Child-Pugh score 7.4+/-0.5) were studied. Hepatic venous pressure gradient, cardiac output, systemic vascular resistance, mean arterial pressure, heart rate and hepatic blood flow were measured before and 1 h after 25 mg carvedilol. After 4 weeks of therapy with carvedilol 25 mg daily, these measurements were repeated before and after rechallenge with carvedilol. Urine volume, sodium excretion and creatinine clearance were also measured before and after 4 weeks of therapy.

RESULTS

Seven patients did not complete the 4-week carvedilol therapy due to hypotension or poor compliance. Hepatic venous pressure gradient fell by 20.8% acutely (p<0.001) and by 16.3% after 4 weeks of therapy (p<0.002). Heart rate, mean arterial pressure and cardiac output fell after acute administration of carvedilol, but only heart rate fell significantly after 4 weeks of treatment. Hepatic blood flow, urine volume, sodium excretion and creatinine clearance remained unchanged after therapy.

CONCLUSION

Carvedilol has beneficial effects on splanchnic haemodynamics following acute and chronic administration in cirrhosis, without compromising hepatic blood flow or renal function. However, a substantial number of patients cannot tolerate 25 mg daily.

Haemodynamic effects of chronic octreotide and tetrandrine administration in portal hypertensive rats

Octreotide is an effective portal hypotensive drug in the control of variceal bleeding. Tetrandrine is a type of calcium channel blocker recently reported to reduce portal hypertension. The present study was undertaken to investigate the haemodynamic effects of octreotide and tetrandrine, alone and in combination, in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation. Portal hypertensive rats were allocated into one of the four groups: vehicle group (saline, 0.5 mL/day), octreotide group (100 microg/kg per 12 h), tetrandrine group (20 mg/kg per 12 h), and octreotide (100 microg/kg per 12 h) plus tetrandrine (20mg/kg per 12 h) group. Tetrandrine or saline was administered by gavage, and octreotide by subcutaneous injection. The drug was given for 8 consecutive days, starting 1 day before ligation and continuing onwards. Haemodynamic parameters were measured thereafter, using the radioactive microsphere method. The portal venous pressure and portal tributary blood flow were significantly reduced, while portal territory and renal vascular resistances were significantly enhanced, by octreotide, tetrandrine, or octreotide plus tetrandrine in portal hypertensive rats, compared with the vehicle group. Our results showed that long-term administration of octreotide, tetrandrine, or octreotide plus tetrandrine led to portal hypotensive effects in portal hypertensive rats, but octreotide alone exerted better anti-hyperdynamic effects compared with tetrandrine alone. A combination of octreotide and tetrandrine offered no major beneficial anti-hyperdynamic effects compared with octreotide alone.