The effects of chronic administration of indomethacin and misoprostol on renal function in cirrhotic patients with and without ascites

Selective cyclooxygenase inhibition by SC-560 improves hepatopulmonary syndrome in cirrhotic rats

Objective

Hepatopulmonary syndrome (HPS) is characterized by hypoxia in patients with chronic liver disease. The mechanism of HPS includes pulmonary vasodilatation, inflammation, and angiogenesis. Prostaglandins synthesized by cyclooxygenases (COX) participate in vascular responsiveness, inflammation and angiogenesis, which can be modulated by COX inhibitors. We therefore evaluated the impact of COX inhibition in rats with common bile duct ligation (CBDL)-induced liver cirrhosis and HPS.

Methods

Cirrhotic rats were randomly allocated to receive non-selective COX inhibitor (indomethacin), selective COX-1 inhibitor (SC-560), or COX-2 inhibitor (celecoxib) for 14 days. After that, hemodynamic parameters, severity of hypoxia and intrapulmonary shunts, liver and renal biochemistry parameters, histological finding and protein expressions were evaluated.

Results

Non-selective COX inhibition by indomethacin improved hepatic fibrosis and pulmonary inflammation in cirrhotic rats with HPS. It also decreased mean arterial blood pressure, portal pressure, and alleviated hypoxia and intrapulmonary shunts. However, indomethacin increased mortality rate. In contrast, selective COX inhibitors neither affected hemodynamics nor increased mortality rate. Hypoxia was improved by SC-560 and celecoxib. In addition, SC-560 decreased intrapulmonary shunts, attenuated pulmonary inflammation and angiogenesis through down-regulating COX-, NFκB- and VEGF-mediated pathways.

Conclusion

Selective COX-1 inhibitor ameliorated HPS by mitigating hypoxia and intrapulmonary shunts, which are related to anti-inflammation and anti-angiogenesis.

Minimizing risks of NSAIDs: cardiovascular, gastrointestinal and renal

Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in treating inflammation, pain and fever, but their cardiovascular, renal and gastrointestinal toxicity can result in significant morbidity and mortality to patients. Techniques for minimizing the adverse risks of NSAIDs include avoiding use of NSAIDs where possible, particularly in high-risk patients; keeping NSAID dosages low; prescribing modified-release and enteric-coated NSAIDs; prescribing cyclooxygenase-2-selective inhibitors where appropriate; monitoring for early signs of side effects; prescribing treatments designed to minimize NSAID side effects; and developing new therapeutic strategies beyond the inhibition of cyclooxygenase. All of the above strategies can be useful in reducing the risk of NSAID complications. The optimal use and management of NSAIDs involves an individualized paradigm approach to establish efficacy with optimal tolerability given the patient risk factors for adverse events.

Renal failure in patients with cirrhosis

Renal failure in cirrhosis poses unique diagnostic and therapeutic challenges. Laboratory values and predictive equations grossly overestimate renal function in patients with cirrhosis. Development of renal failure connotes a worse prognosis; mortality is especially high with hepatorenal syndrome. Classification of the causes of renal failure in patients with cirrhosis is provided with more extensive discussion of selected causes. Finally, a suggested diagnostic approach to renal failure in cirrhosis is given.

Chronic indomethacin treatment enhances the portal-systemic collateral vascular response to vasopressin in bile-duct ligated rats

BACKGROUND

Liver cirrhosis is often accompanied by portal-systemic collateral formation with hemorrhage and encephalopathy. Prostacyclin participates in hyperdynamic circulation and vascular hyporeactiveness to vasoconstrictors in cirrhosis. It has been shown that arginine vasopressin (AVP) induces direct collateral vasoconstriction in portal hypertensive rats, which is potentiated by indomethacin preincubation. However, the influence of chronic indomethacin administration in cirrhosis remains unexplored.

METHODS

This study was performed on male Sprague-Dawley rats with liver cirrhosis induced by common bile duct ligation. They received subcutaneous indomethacin (5 mg/kg/day) or distilled water (control) injection from the 36th to 42nd day after operation. On the 43rd day, systemic and portal hemodynamics were evaluated and the following experiments were performed with an in situ collateral perfusion model: in the first series, concentration-response curves to AVP (10(-10) to 10(-7) M) were obtained; in the second series, flow-pressure curves were plotted (Krebs solution, 6-18 mL/min), where the slope represents an index of collateral vascular resistance (the higher the resistance, the smaller the amount of shunting vessels, that is, the lower the degree of shunting).

RESULTS

The mean arterial pressure and portal pressure were similar between indomethacin and control groups (p > 0.05). Indomethacin elevated the collateral perfusion pressure to AVP (3 x 10(-9), 10(-8) M, p < 0.05) but did not influence the slope of the flow-pressure curve (p > 0.05).

CONCLUSION

In bile duct-ligated cirrhotic rats, indomethacin improves the portal-systemic collateral vascular responsiveness to AVP without alleviating the severity of shunting.

Effects of vasopressin on portal-systemic collaterals of cirrhotic rats

OBJECTIVE

Arginine vasopressin (AVP) exerts a constrictive effect on the portal-systemic collaterals of non-cirrhotic portal hypertensive rats, but its effect on cirrhotic rats is unknown. The aim of this study was to investigate the response of AVP and the modulatory roles of nitric oxide and prostaglandin on collaterals of common bile duct-ligated (BDL) cirrhotic rats.

MATERIAL AND METHODS

The collateral vascular responsiveness to graded concentrations of AVP (10(-10) - 3 x 10(-7) M) was tested by an in situ collateral perfusion system pretreated with Nomega-nitro-L-arginine (L-NNA, 100 microM), indomethacin (INDO, 10 microM), or both. The collateral responses to AVP with the pretreatment of a vasopressin V1 receptor antagonist d(CH2)5Tyr(Me) arginine vasopressin or a V2 receptor agonist 1-desamino-8-D-arginine vasopressin (DDAVP, 10(-10) - 3 x 10(-7) M) were also evaluated.

RESULTS

The perfusion pressure of collaterals was significantly increased by AVP, and this effect was inhibited by the addition of the V1 receptor antagonist. DDAVP had no effect on the collaterals. Incubation with L-NNA or L-NNA plus INDO, but not INDO alone, significantly potentiated the constrictive effects of AVP. The constrictive effect of AVP in the combination group was similar to that in the L-NNA alone group.

CONCLUSIONS

The results show that AVP produces a direct vasoconstrictive effect on the portal-systemic collaterals of BDL cirrhotic rats. The constrictive effect of AVP is mediated by the vasopressin V1, instead of V2, receptors. Nitric oxide may play a more important role than prostaglandin in modulating the collateral vascular response to AVP in BDL cirrhotic rats.

Plasma erythropoietin level in patients with cirrhosis and its relationship to the severity of cirrhosis and renal function

BACKGROUND AND AIM

The level of plasma erythropoietin (EPO) in patients with cirrhosis is controversial. It is known that overproduction of nitric oxide (NO) plays, in part, a role for the development of peripheral arterial vasodilatation in cirrhosis with portal hypertension. It has also been hypothesized that a possible interaction is noted between endogenous EPO and NO production. The current study was undertaken to evaluate the relationship between plasma EPO levels and the severity of liver disease, hemodynamic values, renal functions, and plasma nitrate/nitrite levels in patients with cirrhosis.

METHODS

The authors measured the biochemistry, plasma EPO and nitrate/nitrite levels in 67 patients with cirrhosis (Child-Pugh class A in 23 and Child-Pugh class B and C in 44) and compared their values with those in 34 healthy subjects. Systemic and splanchnic hemodynamic measurements and effective renal plasma flow were obtained from cirrhotic patients.

RESULTS

Plasma EPO and nitrate/nitrite levels were significantly increased in patients with cirrhosis compared with healthy subjects. Additionally, plasma EPO values were higher in cirrhotic patients with ascites or with anemia than in those without ascites or without anemia, respectively. Plasma EPO levels were positively correlated to the hepatic venous pressure gradient (HVPG) and Child-Pugh score, negatively correlated to the renal and hepatic blood flows, but were not correlated to nitrate/nitrite level and systemic vascular resistance in cirrhotic patients. Multiple regression analysis showed that HVPG and renal plasma flow were independent predictors for the elevated EPO level in cirrhotic patients.

CONCLUSIONS

Plasma EPO levels were increased in patients with cirrhosis compared with those in healthy subjects. The increase in plasma EPO levels is related to the degree of portal hypertension, the severity of cirrhosis and the renal plasma flow. In contrast, the EPO levels had no correlation to the nitrate/nitrite levels and systemic vascular resistance in patients with cirrhosis.

Effect of misoprostol on ibuprofen-induced renal dysfunction in patients with decompensated cirrhosis: results of a double-blind placebo-controlled parallel group study

OBJECTIVES

Patients with cirrhosis are prone to develop renal failure upon administration of nonsteroidal anti-inflammatory drugs. The aim of the present study was to determine the safety and efficacy of misoprostol (400 microg) in two repeated doses for the prevention of ibuprofen-induced decrements in renal function in decompensated cirrhotics.

METHODS

Patients were given ibuprofen (800 mg) with either misoprostol (n = 9) or a placebo (n = 10). Sixty minutes later another dose of misoprostol or the placebo was administered. Renal function tests were assessed by clearance techniques.

RESULTS

Administration of ibuprofen with a placebo caused significant decreases in urinary output, inulin clearance, sodium excretion, osmolar clearance, free water clearance, and urinary prostaglandin E2 excretion. Coadministration of ibuprofen and the first misoprostol dose maintained urinary output and sodium excretion, and caused an increase in free water clearance. These changes were maintained only for 1 h. Administration of the second dose of misoprostol temporarily improved inulin and creatinine clearances. Half the patients who received misoprostol suffered from episodes of chills, fever, and diarrhea.

CONCLUSION

Ibuprofen causes renal dysfunction in decompensated cirrhotics, whereas misoprostol may have some protective renal effects, which are, however, short lived and clinically insignificant. Because of side effects, misoprostol should be used with caution in these patients.

Misoprostol therapeutics revisited

Misoprostol, a prostaglandin E1 analog, is a racemate of four stereoisomers. On administration it rapidly de-esterifies to its active form, misoprostolic acid. Misoprostolic acid is 85% albumin bound and has a half-life of approximately 30 minutes. It is excreted in urine as inactive metabolites. No significant drug interactions have been reported. Besides its gastrointestinal protective and uterotonic activities, misoprostol regulates various immunologic cascades. It inhibits platelet-activating factor and leukocyte adherence, and modulates adhesion molecule expression. It protects against gut irradiation injury, experimental gastric cancer, enteropathy, and constipation. It improves nutrient absorption in cystic fibrosis. Misoprostol has utility in acetaminophen and ethanol hepatotoxicity, hepatitis, and fibrosis. It is effective in asthmatics and aspirin-sensitive asthmatic and allergic patients. It lowers cholesterol and severity of peripheral vascular diseases, prolongs survival of cardiac and kidney transplantation, synergizes cyclosporine, and protects against cyclosporine-induced renal damage. It works against drug-induced renal damage, interstitial cystitis, lupus nephritis, and hepatorenal syndrome. It is useful in periodontal disease and dental repair. Misoprostol enhances glycosoaminoglycan synthesis in cartilage after injury. It prevents ultraviolet-induced cataracts and reduces intraocular pressure in glaucoma and ocular hypertension. It synergizes antiinflammatory and analgesic effects of diclofenac or colchicine and has been administered to treat trigeminal neuralgic pain. It reduces chemotherapy-induced hair loss and recovery time from burn injury, and is effective in treating sepsis, multiple sclerosis, and pancreatitis.

New pharmacologic options for renal preservation

The understanding of the cause and pathophysiology of renal failure has guided the rational development of pharmacologic renoprotective strategies. Although traditionally anesthesiologists have focused on renal hemodynamic derangements, newer information suggests that cellular interactions amplify and perpetuate the insult. Consequently, the potential renoprotective armamentarium not only encompasses the more traditional vasoactive agents but also therapeutic approaches that may modify the cellular response to injury. Although few of these agents have reached the clinical arena, preliminary work suggests that this new approach to renal injury and protection may be promising.

Selected drug complications and treatment conflicts in the presence of coexistent diseases

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

Hyperglucagonaemia in cirrhotic patients and its relationship to the severity of cirrhosis and haemodynamic values

Plasma glucagon concentrations were measured in 160 cirrhotic patients (Pugh's grade A in 52 patients, Pugh's grade B in 64 patients and Pugh's grade C in 44 patients). These values were compared with plasma glucagon concentrations in 57 age and sex-matched healthy subjects. Systemic and portal haemodynamic measurements, effective renal plasma flow and creatinine clearance were recorded for each patient. Plasma glucagon levels were significantly increased in cirrhotic patients compared with healthy subjects. In addition, plasma glucagon levels were higher in cirrhotic patients with ascites than in those without ascites and were increased in relation to the severity of cirrhosis as assessed by Pugh's score. Multiple linear regression found that only Child-Pugh's score was estimated to be an independent predictor of hyperglucagonaemia in cirrhotic patients. However, in patients with different degrees of oesophageal varices and in patients without oesophageal varices, plasma glucagon concentrations were no different among the different groups of patients, but were still higher than plasma glucagon concentrations in healthy subjects. In contrast, plasma glucagon levels were negatively correlated with mean arterial pressure and systemic vascular resistance. The results of the present study suggest that impairment of liver function plays, in part, a role in increased plasma glucagon levels observed in patients with cirrhosis. In addition, these data support the hypothesis that hyperglucagonaemia may contribute, at least in part, to the pathogenesis of peripheral arterial vasodilatation in cirrhosis with portal hypertension.

Plasma endothelin levels in patients with cirrhosis and their relationships to the severity of cirrhosis and renal function

BACKGROUND/AIMS

Increased plasma endothelin levels have been reported in patients with cirrhosis. However, the relationship between plasma endothelin concentrations and hyperdynamic circulation or renal functions has not been documented.

METHODS

We measured the plasma endothelin-1 and endothelin-3 concentrations using radioimmunoassay in 96 patients with cirrhosis (Pugh's A in 26, Pugh's B in 45 and Pugh's C in 25) and compared these values to 56 age- and sex-matched healthy subjects. Systemic and portal hemodynamic measurements, effective renal plasma flow, creatinine clearance, plasma aldosterone concentration and plasma renin activity were recorded for each patient.

RESULTS

Plasma endothelin-1 and endothelin-3 levels were significantly increased in patients with cirrhosis compared to healthy subjects. Additionally, plasma endothelin-1 and endothelin-3 values were higher in patients with cirrhosis and ascites than in those without ascites. Moreover, plasma endothelin-1 levels increased in relation to the severity of cirrhosis. On the other hand, modest negative correlations were found between endothelin-1 and creatinine clearance or effective renal plasma flow.

CONCLUSIONS

Plasma endothelin-1 and endothelin-3 levels are increased in patients with cirrhosis compared to healthy subjects. The increase in plasma endothelin-1 levels is related at least in part to the severity of cirrhosis. Increased endothelin-1 levels may possibly contribute to renal dysfunction in patients with cirrhosis.