Pharmacology of propranolol in patients with cirrhosis and portal hypertension

Propranolol can correct prolonged QT intervals in patients with cirrhosis

Background

Prolonged QT intervals are extremely common in patients with cirrhosis and affect their treatment outcomes. Propranolol is often used to prevent gastroesophageal variceal hemorrhage in patients with cirrhosis; however, it is uncertain whether propranolol exerts a corrective effect on QT interval prolongation in patients with cirrhosis.

Aim

The study aimed to investigate the therapeutic effects of propranolol on patients with cirrhosis and prolonged QT intervals.

Methods

A retrospective cohort study approach was adopted. Patients with cirrhosis complicated by moderate-to-severe gastroesophageal varices, who were hospitalized at the Affiliated Hospital of Guangdong Medical University between 1 December 2020 and 31 November 2022, were included in the study. The patients were divided into the propranolol and control groups based on whether they had received propranolol. Upon admission, the patients underwent tests on liver and kidney functions, electrolytes, and coagulation function, as well as abdominal ultrasonography and electrocardiography. In addition to conventional treatment, the patients were followed up after the use or non-use of propranolol for treatment and subsequently underwent reexamination of the aforementioned tests.

Results

The propranolol group (26 patients) had an average baseline corrected QT (QTc) interval of 450.23 ± 37.18 ms, of which 14 patients (53.8%) exhibited QTc interval prolongation. Follow-up was continued for a median duration of 7.00 days after the administration of propranolol and conventional treatment. Electrocardiographic reexamination revealed a decrease in the QTc interval to 431.04 ± 34.64 ms (p = 0.014), and the number of patients with QTc interval prolongation decreased to five (19.2%; p < 0.001). After treatment with propranolol and multimodal therapy, QTc interval normalization occurred in nine patients with QTc interval prolongation, leading to a normalization rate of 64.3% (9/14). The control group (n = 58) had an average baseline QTc interval of 453.74 ± 30.03 ms, of which 33 patients (56.9%) exhibited QTc interval prolongation. After follow-up for a median duration of 7.50 days, the QTc interval was 451.79 ± 34.56 ms (p = 0.482), and the number of patients with QTc interval prolongation decreased to 30 (51.7%; p = 0.457). The QTc interval normalization rate of patients in the control group with QTc interval prolongation was merely 10.0% (3/33), which was significantly lower than that in the propranolol group (p < 0.001).

Conclusion

In patients with cirrhosis complicated by QT interval prolongation, the short-term use of propranolol aids in correction of a long QT interval and provides positive therapeutic value for cirrhotic cardiomyopathy.

Polypharmacy in chronic liver disease patients: Implications for disease severity, drug-drug interaction, and quality of life

Multiple prescriptions for different medications may be needed for chronic conditions, increasing the risk of polypharmacy. The WHO defined polypharmacy as "the administration of many drugs at the same time or the administration of an excessive number of drugs". The primary goal of this study was to evaluate polypharmacy in patients with chronic liver disease and to identify potential drug-drug interactions associated with it. A cross-sectional study was conducted at a tertiary care hospital in Mangalore, Karnataka, for six months, from November 2020 to April 2021. The study involved 118 patients with chronic liver disease from various age groups. Data was gathered by analyzing patients' medical records kept on the ward and interviewing them individually. In admission and discharge prescriptions, polypharmacy was examined. Online interaction checkers from Drugs.com and Medscape were used to interpret potential drug-drug interactions. The SF-36 and Chronic Liver Disease Questionnaire were used to measure the quality of life. The data obtained were analyzed statistically to determine the significant correlation. The number of prescribed drugs was significantly correlated (P = 0.018) with the severity of liver disease in Child-Pugh categories B and C. Additionally, moderate polypharmacy reduced quality of life (P < 0.05), and the physical health category was significantly associated with disease severity (P < 0.05). Drug-drug interactions were found in 108 out of the 118 examined prescriptions, totaling 586 interactions in the admission list and 405 interactions in the discharge list. If the potentially serious main drug interaction identified in this study is not well monitored, it could lead to a serious, potentially fatal health condition. Despite being advised, safety is not always guaranteed by liver enzyme monitoring. Therefore, healthcare providers must take additional precautions to avoid inappropriate prescribing, minimize side effects, and ensure drug safety.

Development and Evaluation of a Physiologically Based Pharmacokinetic Drug-Disease Model of Propranolol for Suggesting Model Informed Dosing in Liver Cirrhosis Patients

AIM

The study was aimed to understand the underlying causes for the differences in propranolol pharmacokinetics (PK) between healthy and cirrhosis populations by using a systematic whole-body physiologically based pharmacokinetic (PBPK) model-building approach for suggesting model informed propranolol dosing in liver cirrhosis patients with different stages of disease severity.

METHODS

A whole-body PBPK model was developed by using population simulator PK-Sim® by using reported physicochemical and clinical data for propranolol in healthy and liver cirrhosis populations. The model evaluation was done by visual verification and comparison of PK parameters using their observed/predicted ratios (Robs/pred).

RESULTS

The developed model has effectively described the disposition of propranolol after intravenous and oral application in healthy and liver cirrhosis populations. All the model predictions were comparable to the observed clinical data and the Robs/pred for all the PK parameters were within a 2-fold range. A significant increase in plasma concentration of propranolol and decrease in drug clearance was observed in progressive stages of liver cirrhosis. The developed model after evaluation with the reported clinical PK data was used for suggesting model informed propranolol dosing in different stages of liver cirrhosis based on systemic unbound drug concentration.

CONCLUSION

The developed PBPK model has successfully described propranolol PK in healthy and cirrhosis populations after IV and oral administration. The evaluated PBPK propranolol-cirrhosis model can have many implications in predicting propranolol dosing in liver cirrhosis patients with different stages of disease severity.

Non-selective beta-blockers increase overall and liver mortality in alcoholic cirrhosis with MELD ≥ 12 over 5 years of follow-up

BACKGROUND & AIMS

Non-cardioselective beta-blocker (NSBB) effects on mortality in cirrhosis are controversial. We evaluated the impact of NSBBs on mortality according to liver severity and mortality cause.

METHODS

Two hundred and fifty-eight patients with alcoholic cirrhosis were included in a retroprospective cohort: 129 NSBB-treated and 129 controls. The NSBB group had the following significant baseline differences: higher MELD, more frequent previous gastrointestinal bleeding, large oesophageal varices (OV) and lower heart rate. Propranolol dose was 160 mg/d in 81% of NSBB patients.

RESULTS

(i) Liver function: during 5.3 ± 2.6 years of follow-up, MELD progression was higher in NSBB patients: 1 (-1-4) than in controls: 0 (-1-1) (P = .017). (ii) Overall survival: no significant differences were observed between NSBBs and controls (Kaplan-Meier curves: P = .291). In multivariate Cox analysis, baseline MELD interacted with NSBB (P = .011). Thus, the NSBB hazard ratio (HR) was 0.99 (0.50-1.98) in MELD < 12 vs 3.17 (1.19-8.42) in MELD ≥ 12. (iii) Liver survival: NSBB decreased liver survival (Kaplan-Meier: P = .031). In multivariate Cox analysis, baseline MELD interacted with NSBB (P < .001). The NSBB HR was 0.81 (0.30-2.19) in MELD < 12 vs 6.23 (1.94-20.0) in MELD ≥ 12. In competing risk multivariate analysis for liver mortality, the MELD-NSBB interaction was significant (P < .001): the NSBB HR was 1.02 (0.36-2.91) in MELD < 12 vs 9.24 (3.18-26.9) in MELD ≥ 12. 4) Non-liver survival: contrastingly, non-liver survival was increased by NSBBs, especially in MELD ≥ 12 (competing Kaplan-Meier: P = .044). These results were confirmed in propensity risk score (PRS)-matched patients.

CONCLUSION

In alcoholic cirrhosis with rather high propranolol doses, overall and liver survival are significantly aggravated when MELD is ≥12.

A study of the relationship between serum bile acids and propranolol pharmacokinetics and pharmacodynamics in patients with liver cirrhosis and in healthy controls

The main objectives of the study were to determine the exposure and bioavailability of oral propranolol and to investigate their associations with serum bile acid concentration in patients with liver cirrhosis and in healthy controls. A further objective was to study the pharmacodynamics of propranolol. An open-label crossover study was performed to determine the pharmacokinetics and pharmacodynamics of propranolol after oral (40 mg) and intravenous (1 mg) administration as well as the concentration of total and individual fasting serum bile acids in 15 patients with liver cirrhosis and 5 healthy controls. After intravenous propranolol, patients showed a 1.8-fold increase in the area under the plasma concentration-time curve (AUC_0–∞), a 1.8-fold increase in volume of distribution and a 3-fold increase in the elimination half-life (mean ± SEM: 641±100 vs. 205±43 minutes) compared to controls. After oral application, AUC_0–∞ and elimination half-life of propranolol were increased 6- and 4-fold, respectively, and bioavailability 3-fold (83±8 vs. 27±9.2%). Maximal effects on blood pressure and heart rate occurred during the first 4 and first 2 hours, respectively, after intravenous and oral application in both patients and controls. Total serum bile acid concentrations were higher in patients than controls (42±11 vs. 2.7±0.3 µmol/L) and were linearly correlated with the serum chenodeoxycholic acid concentration. There was a linear correlation between the SBA concentration and propranolol oral AUC_0–∞ in subjects not receiving interacting drugs (r² = 0.73, n = 18). The bioavailability of and exposure to oral propranolol are increased in patients with cirrhosis. Fasting serum bile acid concentration may be helpful in predicting the exposure to oral propranolol in these patients.

H3 Propranolol serum levels following lidocaine administration in rats with CCL4 — induced liver damage

Liver disease alters the pharmacokinetic and pharmacodynamic properties of hepatically eliminated drugs. The main factors influenced are plasma albumin levels, enzyme balance (induction & inhibition) and drug binding to tissue proteins. The influence of lidocaine on serum, heart and liver propranolol levels in Wistar rats after liver injury induced by carbon tetrachloride CCl4 0.4 ml/kg x 2/wkl, was investigated. 40 male Wistar rats were divided into four groups (I, II, III, IV; n=10), Group I animals received only propranolol (labelled + cold substance) 40 mg/kg/12 h p.o., group II propranolol plus lidocaine in a single dose of 4mg/kg s.c., group III was treated with CCl4 for 6 weeks and received propranolol x2 at the same dosage as group I, while group VI was treated with CCl4 and the same drug dosage as group II. The simultaneous administration of H3-propranolol and lidocaine increased propranolol levels in the serum and tissues. The liver in damaged animals showed an increase of propranolol level under lidocaine co-administration, probably due to CCl4 induced liver enzyme activity, resulting in a rapid propranolol metabolism or to competition between both drug protein binding sites. The increased propranolol levels in the heart after lidocaine administration were probably due to attributed to its high affinity for heart tissue. Consequently, as regards the therapeutic approach for patients with liver disease receiving propranolol their propranolol dosage should be reduced when lidocaine is co-administered.

The Pharmacokinetics of Single Dose vs Steady-State Doses of Propranolol in Cirrhotic Malay Patients

Pharmacokinetics of propranolol (PRN) given orally were studied in twelve cirrhotic Malay patients [10 males, 2 females], aged 33-62 years [49.83±9.17], body weight 39-72 kg [58.0±8.46] and height 142-168 cm [158.8±7.89] following single 20 mg and steady-state 20 mg tds for 7 days dosing of PRN. Blood samples were withdrawn hourly up to 48 hours. PRN concentrations in the plasma were assayed by HPLC with oxprenolol as the internal standard. Pharmacokinetic parameters were analysed using a non-linear regression program MultiForte. Area under the curve (AUC) as performed using the linear trapezoidal rule. Student's t-test was used to test for statistical significance and AUC in Malay cirrhotic patients was found to be much bigger than that observed in Caucasians. Steady-state AUC was significantly increased following multiple dosing (961.31±7.47 vs 2954.19±1153.34 ng.hr/ml), however, the volume of distribution (V(d)) declined (543.89±292.91 vs 224.14±1003.12 L) significantly compared to that of a single dose. The apparent systemic clearance (CL) was significantly reduced at steady-state (436.04±209.4 vs 129.51±48.42 ml/min) in comparison to single dose therapy. The peak plasma concentration (Cp(max)) was greatly increased at steady-state (54.32±22.37 vs 136.10±38.63 ng/ml). Based on the AUC, PRN bioavailability was greater in cirrhotic Malay patients compared to Caucasians who took only 20 mg instead of 80 mg doses. The decline in drug clearance following steady-state was due to saturation of the metabolizing capacity of hepatic enzymes and a decreased portal blood flow. Reduced V(d) was believed to be caused by increased drug-receptor interactions and decreased tissue/protein binding of PRN in these patients.

Haemodynamic effects of propranolol, octreotide and their combination during fasting and post-prandial splanchnic hyperaemia in patients with cirrhosis

BACKGROUND/AIMS

This double-blind study was designed to evaluate the haemodynamic effect of two drugs, propranolol and octreotide, and their combination in patients with cirrhosis.

METHODS

Fifteen patients with cirrhosis were randomly assigned to two groups receiving either octreotide subcutaneously at 100 microg ('octreotide' group, n = 9) or propranolol orally at 40 mg followed by a subcutaneous dose of octreotide (100 microg) after 1 h ('propranolol + octreotide' group, n = 6); then, after 30 min, a standard meal was administered to both groups. The hepatic vein pressure gradient by hepatic vein catheterization, portal and superior mesenteric artery blood flow velocity, superior mesenteric artery pulsatility index by the echo-Doppler duplex system were recorded at baseline, 1 h after propranolol in the 'propranolol + octreotide' group, and in both groups 30 min after octreotide and 30 min after meal.

RESULTS

At fast, propranolol was more active in decreasing portal pressure (from 16 +/- 2.2 to 12.7 +/- 3.8 mmHg, -20%, P < 0.05) as compared to octreotide (from 18.6 +/- 4.8 to 16.6 +/- 4.3 mmHg, -11%, P < 0.05). Conversely, octreotide was more active on the mean blood flow velocity of superior mesenteric artery (from 22.8 +/- 5 to 19 +/- 4.5 cm/ s, -17%; P< 0.05). Octreotide administration in patients receiving beta-blockers showed, also, a trend to increase the mesenteric vascular resistances (pulsatility index from 3.14 +/- 0.69 to 3.68 +/- 1.29, +17%, not significant (NS)) which had not been affected by previous treatment with propranolol. After the meal, a reduction of the expected hyperaemic response occurred in both groups.

CONCLUSIONS

The combined acute haemodynamic effect of this association suggests the possible combination of these two drugs in critical situations, such as variceal bleeding in patients receiving beta-blockers. The simultaneous use of echo-Doppler and hepatic vein catheterization permitted us a more complete analysis of the acute haemodynamic events.

Propranolol stereoisomer plasma concentrations and portal haemodynamic response in patients with liver cirrhosis

BACKGROUND

The haemodynamic effect of propranolol on portal pressure in patients with portal hypertension is highly variable and does not correlate with propranolol racemate plasma concentrations.

AIM

To investigate the stereoselective metabolism of the propranolol enantiomers and its impact on portal haemodynamics in patients with liver cirrhosis since only S-propranolol is haemodynamically active.

METHODS

Twenty patients with liver cirrhosis and portal hypertension received 40 mg propranolol orally. Portal blood velocity (PBV) and propranolol stereoisomer plasma concentrations were determined.

RESULTS

During the 4 h examination period we observed a significant reduction in PBV (18.3 +/- 2.2%, P < 0.0001) vs. baseline. The area under the curve (AUC) during the study period was significantly different for the two isomers (S-propranolol 1217.0 +/- 118.5 nmol.h/L; R-propranolol 728.8 +/- 103.8 nmol.h/L, P < 0.0001). Seven patients (35%) were portal haemodynamic non-responders to propranolol. Propranolol stereoisomer AUC values were no different between responders (S-propranolol 1133. 3 +/- 132.0 nmol.h/L; R-propranolol 718.0 +/- 129.7 nmol.h/L) and non-responders (S-propranolol 1371.8 +/- 250.5 nmol.h/L; R-propranolol 746.9 +/- 200.3 nmol.h/L); neither was there a correlation between propranolol enantiomer plasma concentrations and the portal haemodynamic effect.

CONCLUSIONS

Our data demonstrate a stereoselective metabolism of propranolol enantiomers in liver cirrhosis. However, following oral propranolol administration, stereoisomer plasma concentrations do not predict the portal haemodynamic effect.

A randomized study of propranolol on postprandial portal hyperemia in cirrhotic patients

Propranolol, a nonselective beta-adrenergic blocker, has been shown to reduce portal pressure and the risk fo variceal bleeding. The portal pressure-reducing effect of propranolol is mediated by splanchnic arterial constriction, which decreases portal flow. A double-blind randomized control study (crossover on 2 consecutive days) was designed to compare the effects of propranolol vs. placebo on portal flow in cirrhotic patients during fasting and after a standardized meal. Portal flow was measured with an ATL Ultramark 8 echo-Doppler system (Advanced Technological Laboratories, Bothel, WA) in 23 cirrhotic patients. Fasting portal flow and heart rate were obtained at baseline and 2 hours after the administration of propranolol or placebo. A standard test meal was then given, and measurements were repeated 30 minutes later. Thirteen patients (group 1) received placebo on day 1 and propranolol on day 2, whereas 10 patients (group 2) received propranolol on day 1 and placebo on day 2. In group 1 patients, heart rate declined by 20% (P less than 0.0001) and portal flow decreased by 12% (P less than 0.05) after propranolol administration. Similar reductions were found in heart rate (-21%, P less than 0.0001) and portal flow (-17%, P less than 0.001) for group 2 patients. For all 23 patients, 2 hours after propranolol administration, heart rate declined by 21% (P less than 0.0001) and portal blood flow was reduced by 14% (P less than 0.0001). The 10 patients who received propranolol on day 1 (group 2) showed a carryover effect of propranolol on day 2. On day 2, baseline portal flow and heart rate values were significantly lower than baseline values on day 1. This long-lasting effect of a single dose of propranolol may be caused by the longer half-life of propranolol in cirrhotic patients. The postprandial portal blood flow percentage increase after the meal was similar for both placebo and propranolol. Propranolol did not blunt postprandial hyperemia. However, whereas the absolute value of blood flow after the meal increased significantly in comparison with baseline in placebo-treated patients (P less than 0.001), this did not occur with propranolol. Furthermore, in propranolol-treated patients the absolute value of blood flow after the meal was lower than in placebo-treated patients. This may constitute a protective effect of propranolol in portal hypertension.

Pharmacodynamic and pharmacokinetic study of propranolol in patients with cirrhosis and portal hypertension

1. The aim of this study was to investigate the pharmacokinetics and the beta-adrenoceptor blocking activity according to time of conventional (C) and long acting (LA) propranolol in cirrhotic patients. Twenty-four patients with alcoholic cirrhosis and oesophageal varices were randomly assigned to receive either 160 mg C propranolol, 160 mg LA propranolol or placebo acutely and then following repeated administration (acute and chronic phases). Thereafter propranolol concentrations and beta-adrenoceptor blockade (resting and exercise heart rates) were measured at different intervals. 2. The Cmax was significantly higher with C propranolol in both phases. The time of Cmax was significantly later with LA propranolol in both phases. The AUCs were significantly higher after chronic administration with both formulations of propranolol. 3. The exercise peaks of beta-adrenoceptor blockade were similar between the two formulations and between the two phases of administration of propranolol. The duration of effective beta-adrenoceptor blockade was significantly longer in the chronic phase and seemed to be longer with LA than with C propranolol although this was not significant (72 +/- 31 vs 48 +/- 18 h, respectively). 4. There was a significant correlation between the log propranolol concentration and exercise heart rate but not with resting heart rate. No correlation could be demonstrated between pharmacological data and the Child Pugh score. 5. We conclude that in cirrhotic patients exercise testing was a reliable method in the assessment of beta-adrenoceptor blockade. Pharmacology of propranolol was found to be different according to the formulation or to the phase of administration.

Propranolol does not alter cerebral blood flow and functions in cirrhotic patients without previous hepatic encephalopathy

Since it has been suggested that propranolol could lead to hepatic encephalopathy, we undertook a study to assess the effects of propranolol on cerebral blood flow and cerebral functions. Sixteen patients with alcoholic cirrhosis and large esophageal varices and without major hepatic dysfunction (Child-Pugh score less than 14) or previous hepatic encephalopathy were randomized to receive either propranolol or placebo. The following measurements were performed before and 15 min after single intravenous administration of 15 mg propranolol or placebo and again 1 week after chronic oral administration of propranolol 160 mg per day or placebo: cerebral blood flow by the xenon-133 inhalation technique, quantitative electroencephalogram, psychometric test (number connection test), arterial ammonia, pH and pCO2, resting and exercise heart rates (after single administration, electroencephalogram, number connection test and biochemical measurements were not performed). Cerebral blood flow was not significantly modified by treatment (propranolol group: 80 +/- 23 vs. 76 +/- 11 and 83 +/- 9; placebo group: 73 +/- 10 vs. 75 +/- 11 and 81 +/- 18 ml per 100 gm per min, respectively, before and after single and repeated administration). Likewise, neither of the two treatments significantly altered number connection test, quantitative electroencephalogram index, arterial ammonia, pH and pCO2. We conclude that, in this population of cirrhotic patients, propranolol did not alter cerebral blood flow or neuropsychological functions. As a consequence, hemodynamic alterations cannot be considered as causes of possible cerebral side effects of propranolol in cirrhotic patients without severe hepatic dysfunction and previous hepatic encephalopathy.

Beta-blockade prevents recurrent gastrointestinal bleeding in well-compensated patients with alcoholic cirrhosis: a multicenter randomized controlled trial

To assess the efficacy of beta-blockers in preventing rebleeding in selected cirrhotic patients and to compare the tolerance, safety and patient compliance of a selective and a nonselective beta-blocker, 94 patients were randomly assigned to propranolol (32 patients), atenolol (32 patients) or placebo (30 patients). Randomization was made at least 15 days after the bleeding episode. Propranolol was given orally at increasing doses until the resting pulse rate was reduced by approximately 25%. Atenolol was given at a fixed dose of 100 mg per day. Patients were followed up for a mean of 357 days. Rebleeding occurred in 14 patients in the placebo group, 10 in the atenolol group and eight in the propranolol group. The incidence of rebleeding was significantly lower in patients receiving propranolol than in those on placebo (propranolol vs. placebo: p = 0.01, logrank test). Atenolol was less effective than propranolol (atenolol vs. placebo: p = 0.065, logrank test). Bleeding-free survival was better for patients on active drugs than for those on placebo (propranolol vs. placebo = p = 0.01, atenolol vs. placebo: p = 0.05, logrank test). Retrospective analysis revealed that, whatever the type of treatment, abstinence from alcohol was crucial in preventing rebleeding. We conclude that beta-blocker treatment is effective in preventing rebleeding from esophageal varices in carefully selected alcoholic cirrhotic patients who survive at least 2 weeks after acute variceal hemorrhage and stop drinking.

Safety of propranolol in portal hypertension. Conventional and long acting formulations

Propranolol is likely to be widely used to prevent variceal haemorrhage in patients with cirrhosis. Adverse reactions to propranolol in this group of patients are unusual, although the treatment group as a whole appears to tolerate drug therapy poorly. Therefore, compliance is likely to be a limiting factor, particularly in the prophylactic setting, and the use of once-daily long acting propranolol, which appears to be equally effective, has distinct advantages over the conventional, shorter acting formulation.

Beta-blockers in the secondary prevention of gastrointestinal haemorrhage in well-compensated cirrhotics. A multicentre randomised controlled study

To assess the efficacy of beta-blockers in the prevention of rebleeding in selected cirrhotics and to compare the tolerability, safety of, and patient compliance with, a selective and a non-selective beta-blocker, 94 patients were randomly assigned to propranolol (32), atenolol (32), or placebo (30). Randomisation was made at least 15 days after the bleeding episode. Propranolol was given orally in increasing doses until the resting pulse rate was reduced by approximately 25%. Atenolol was given at a fixed dose of 100 mg/day. Patients were followed up for a mean of 357 days. Rebleeding occurred in 14 patients in the placebo group, 10 in the atenolol group and 8 in the propranolol group. The incidence of rebleeding was significantly lower in patients receiving propranolol than in those on placebo (PR vs PL: p less than 0.01, log-rank test). Atenolol was less effective than propranolol (AT vs PL: p = 0.065, log-rank test) but bleeding-free survival was improved for patients on active drugs compared with those patients on placebo (PR vs PL: p = 0.01; AT vs PL: p = 0.05, log-rank test). Retrospective analysis revealed that, whatever the type of treatment, abstinence from alcohol was crucial in preventing rebleeding. It was concluded that beta-blocker treatment is effective in preventing rebleeding from oesophageal varices in carefully selected alcoholic cirrhotics who survive at least 2 weeks after acute variceal haemorrhage and who cease drinking.

Review: the pharmacological control of variceal bleeding

The haemodynamic effects and clinical uses of drugs used in the management of patients with oesophageal variceal bleeding are reviewed. Vasoconstrictor agents (vasopressin, teripressin) alone or in combination with nitrates continue to be used for acute bleeding episodes, while somatostatin is an alternative. Alpha- and beta-adrenergic blocking drugs and vasodilators which lead to a sustained decrease in portal pressure can be used for the prevention of bleeding episodes, but despite numerous studies the pharmacological treatment of variceal bleeding remains controversial.

Long-term effects of beta-adrenergic blockade with nadolol on hepatic and renal haemodynamics and function in cirrhotics

Non-cardioselective beta-blockers are used for prevention of re-bleeding from oesophageal varices in cirrhotics with portal hypertension. Nadolol, a non-cardioselective beta-blocker with a low liposolubility and a low hepatic metabolism, has been demonstrated to decrease portal pressure in cirrhotic patients. Since cirrhotics need long-term treatment, we investigated long-term effects of beta-adrenergic blockade with nadolol on hepatic and renal haemodynamics and function in a group of patients with cirrhosis and portal hypertension. In 19 patients with cirrhosis, after one and six months of treatment with nadolol hepatic venous pressure gradient showed a significant and persistent decrease, averaging 19% and 22%, respectively. Hepatic function and renal haemodynamics and function remained unaffected. Oesophageal varices severity was lowered in 11/19 patients after one month, in 9/16 after six months, in 8/14 after 12 months and in 5/10 after 18 months. Our results showed that, also after long-term treatment, nadolol decreases portal pressure and, in approximately 50% of patients, oesophageal varices severity, without side-effects on liver and renal function.

A comparative pharmacokinetic study of conventional propranolol and long acting preparation of propranolol in patients with cirrhosis and normal controls

1 Six male patients with alcoholic cirrhosis and seven normal control subjects were each given 80 mg twice daily of conventional propranolol for 1 week and 160 mg once daily of a long acting preparation (LA) of propranolol for 1 week. 2 Plasma propranolol levels were measured at regular intervals on the first and seventh days of both weeks and also following an acute intravenous infusion of 10 mg propranolol on a separate occasion. 3 After the single intravenous dose the elimination half-life tended to be prolonged in the cirrhotic group (median 7.15 h) compared with controls (median 2.92 h) (P = 0.055). 4 After multiple oral dosing with 80 mg twice daily of conventional propranolol the steady-state plasma concentration (Css), area under the curve (AUC tau), peak concentration (Cmax) and trough concentration (Cmin) were significantly higher in cirrhotic patients and the peak: trough ratio (Cmax/Cmin) was significantly lower than controls. 5 After multiple oral dosing with 160 mg LA once daily Cmin was significantly higher than Cmax/min significantly lower in cirrhotic patients; Css, AUC and Cmax were higher than controls but not statistically different. 6 Within both subject groups the bioavailability of 80 mg twice daily of conventional propranolol tended to be greater than 160 mg LA once daily. Cmax was significantly higher in both groups and Css higher in the cirrhotic group with conventional propranolol. 7 In the cirrhotic group the mean reduction in supine heart rate in the steady state was 31.8% with conventional 80 mg twice daily propranolol and 23.75% with 160 mg LA once daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacokinetics of beta-adrenoceptor antagonists. An update

The beta-adrenoceptor antagonists have been widely used clinically for over 20 years and their pharmacokinetics have been more thoroughly investigated than any other group of drugs. Their various lipid solubilities are associated with differences in absorption, distribution and excretion. All are adequately absorbed, and some like atenolol, sotalol and nadolol which are poorly lipid-soluble are excreted unchanged in the urine, accumulating in renal failure but cleared normally in liver disease. The more lipid-soluble drugs are subject to variable metabolism in the liver, which may be influenced by age, phenotype, environment, disease and other drugs, leading to more variable plasma concentrations. Their clearance is reduced in liver disease but is generally unchanged in renal dysfunction. All the beta-adrenoceptor antagonists reduce cardiac output and this may reduce hepatic clearance of highly extracted drugs. In addition, the metabolised drugs compete with other drugs for enzymatic biotransformation and the potential for interaction is great, but because of the high therapeutic index of beta-adrenoceptor antagonists, any unexpected clinical effects are more likely to be due to changes in the kinetics of the other drug. Because satisfactory plasma concentration effect relationships have been difficult to establish for most clinical indications, and little dose-related toxicity is seen, plasma beta-adrenoceptor antagonist concentration measurement is usually unnecessary. The investigation of the clinical pharmacokinetics of the beta-adrenoceptor antagonists has added greatly to our theoretical and practical knowledge of pharmacokinetics and made some contribution to their better clinical use.

Systemic haemodynamics, renal and platelet function during chronic propranolol administration in patients with compensated cirrhosis

Chronic propranolol administration is followed by some haemodynamic alterations, which may impair renal function. It has also been suggested that it may reduce platelet production of proaggregatory thromboxane (TX) A2. We therefore evaluated cardiac index (CI), systemic vascular resistance (SVR), creatinine clearance, daily sodium excretion under controlled sodium intake, platelet aggregation and platelet TXA2 production during whole blood clotting in eight patients with cirrhosis, portal hypertension and no ascites, before and after 3 months of propranolol administration. Liver function was also assessed by evaluating the galactose elimination capacity (GEC) and galactose clearance (Cgal). The expected, significant reduction of CI and increase of SVR was observed. Creatinine clearance and sodium balance were unchanged throughout the study. Furthermore, the renal prostaglandin system, as reflected by urinary prostaglandin E2 and TXB2 excretion, was also unaffected by the drug. No modification of platelet aggregation, platelet TXA2 production during whole blood clotting, GEC and Cgal was observed. We conclude that chronic propranolol administration is followed by alterations of CI and SVR, but it does not impair renal function and platelet aggregation in patients with cirrhosis, portal hypertension and no ascites. The maintenance of renal function during beta-adrenergic blockade is not due to an increased renal production of vasodilating prostaglandins.

Evidence for down-regulation of beta-2-adrenoceptors in cirrhotic patients with severe ascites

The density and affinity of beta-2-adrenoceptors on mononuclear cells from peripheral blood were studied in fifteen patients with cirrhosis of different severity and in thirteen controls. There was no significant difference between cirrhotic patients and controls in density or affinity of beta-2 binding sites. Within the cirrhotic group, however, the number of binding sites per cell was significantly lower in patients with severe ascites than in patients with mild to moderate or no ascites. This down-regulation of beta-adrenoceptors could influence the haemodynamic response to beta-blockers.