Effect of metoclopramide on portal blood flow in patients with liver cirrhosis, measured by the pulsed Doppler system

Effect of cisapride on portal haemodynamics in patients with liver cirrhosis using duplex Doppler ultrasonography

PURPOSE

Cisapride, a benzimide derivative, is a gastrointestinal prokinetic agent without dopamine-antagonistic or cholinomimetic effects. This study aims at assessing the effect of cisapride oral administration on portal flow in patients with advanced post hepatitic cirrhosis using duplex Doppler ultrasound (US).

METHODS

A total of 12 patients with post-hepatitic liver cirrhosis were included in the study. Duplex Doppler sonographic examinations were performed before and after treatment. The subjects received 10 mg cisapride before starting the measurement procedure and then three times a day for 2 days. Portal haemodynamics including vessel diameters (mm), mean flow velocities (cm/s), blood flows (ml/min) were investigated.

RESULTS

Mean portal vein diameters, mean portal flow velocity and portal blood flow volume showed decreases of 18.6, 22.1 and 43.6% (P<0.001), respectively. After cisapride administration the portal vein diameter did not change in two patients and the portal vein velocity did not change in three patients. No significant change was found in systolic blood pressure, diastolic blood pressure or pulse rate after the administration of cisapride.

CONCLUSION

In this study, it was demonstrated that oral administration of cisapride results in a significant reduction of portal blood flow but there were no changes in heart rate or systolic pressure in patients with cirrhosis of the liver.

Metoclopramide inhibits development of esophageal varices in rat model

We examined the preventive effect of metoclopramide on the development of esophageal varices in a rat model. Thirty rats were divided into three groups: metoclopramide (7.5 mg/kg twice a day, intraperitoneally), control group I (saline 2 ml/kg twice a day, intraperitoneally), and control group II (incised lower esophageal sphincter and metoclopramide 7.5 mg/kg twice a day, intraperitoneally). On the 14th postoperative day, lower esophageal sphincter pressure in the metoclopramide group (8.6 +/- 1.4 cm H2O) increased more than in the control groups (5.4 +/- 0.5, 5.0 +/- 0.5 cm H2O, P < 0.01). Development of small collateral vessels from the spleen to the retroperitoneum was evident only in the metoclopramide group, as seen on the portography (P < 0.01). Histologically, the variceal area of the horizontal cross section of the esophagus in the metoclopramide group (0.62 +/- 0.26 mm2) was significantly smaller than in the controls (2.67 +/- 0.95, 2.78 +/- 0.82 mm2), determined using an image processor-analyzer for photographing histological specimens (P < 0.01). We also investigated the effect of metoclopramide on smooth muscle cells in the rat portal vein, using isometric-tension recording. Metoclopramide relaxed the smooth muscle precontracted with norepinephrine, in a concentration-dependent manner. Thus, metoclopramide inhibits the development of esophageal varices in this rat model due to both an increase in resistance of the lower esophagus and to development of small collaterals.

Pharmacological treatment of portal hypertension: hemodynamic effects and prevention of bleeding

In the past 10 years, it has been clearly shown that vasoactive substances reduce portal pressure in patients or animals with portal hypertension. Some of these substances act by inducing splanchnic vasoconstriction, while others reduce hepatic and porto-systemic collateral vascular resistance and, thus, induce a portal hypotensive effect. Still others induce arterial hypotension, which causes a vasoconstrictive effect in the splanchnic territory. Since these drugs act on different vascular receptors, their combination should have a more marked effect on portal hypertension. Up to now, only nonselective beta-blockers have been used in the prevention of first gastrointestinal bleeding in patients with portal hypertension and esophageal varices and in the prevention of recurrent gastrointestinal bleeding. These trials have shown that propranolol or nadolol significantly reduce either a first episode of bleeding or recurrent bleeding. This pharmacological treatment also improves the survival rate in these patients. All of these studies have helped us to understand, in part, why gastrointestinal hemorrhage occurs in certain patients. Additional studies of beta-blockers or other substances are, nevertheless, necessary to select patients who will respond to this type of treatment. Finally, it is possible that the pharmacological treatment of portal hypertension may also be used before esophageal varices occur.