Pharmacology, clinical efficacy and safety of terlipressin in esophageal varices bleeding, septic shock and hepatorenal syndrome

A Review of Terlipressin in Hepatorenal Syndrome: Targeting Endothelial Dysfunction and Subsequent Cardiovascular Adverse Events

Hepatorenal syndrome (HRS) is a serious complication of decompensated liver cirrhosis that results in acute kidney injury (AKI). The mortality rate is high. Endothelial dysfunction secondary to liver cirrhosis is a key driver of the development of portal hypertension, which is eventually complicated by ascites and HRS. Ultimately, splanchnic vasodilation and excess gut lymph production result in ascites, low effective arterial blood volume, and maladaptive compensatory mechanisms that contribute to renal hypoperfusion and injury. While the only curative treatment is liver transplantation, vasoconstrictors and albumin have been the mainstay of treatment for candidates who are ineligible or waiting for transplantation. On September 14, 2022, terlipressin, a V1 vasopressin receptor agonist, was approved by the Food and Drug Administration for the treatment of HRS-AKI. In clinical trials, terlipressin plus albumin have been superior to albumin alone and equivocal to noradrenaline plus albumin in renal function improvement. Terlipressin, however, does not improve survival, is costly, and is associated with severe adverse events-including severe cardiac and vascular complications. The aim of this review is to provide an overview of terlipressin pharmacology, adverse events-with a focus on cardiovascular complications-and comparative randomized controlled trials that resulted in the Food and Drug Administration's approval of terlipressin. New literature since its approval and ongoing clinical trials will also be highlighted.

Effect of different infusion approaches on safety and efficacy of terlipressin: Current controversies

Terlipressin, a synthetic analog of vasopressin, has been widely used to treat acute variceal bleeding, hepatorenal syndrome, and other complications of cirrhosis. However, among different infusion approaches of terlipressin, its safety and efficacy are also heterogeneous. Previous studies have demonstrated that continuous infusion of terlipressin is more effective with a lower incidence of adverse events than intermittent intravenous infusion. This paper aims to review the relevant literature and summarize the data regarding the safety and effectiveness of different infusion approaches of terlipressin to guide clinical practice.

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.

Computational basis of SARS-CoV 2 main protease inhibition: an insight from molecular dynamics simulation based findings

The coronavirus disease 2019 (COVID-19) pandemic is caused by newly discovered severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). One of the striking targets amongst all the proteins in coronavirus is the main protease (M^pro), as it plays vital biological roles in replication and maturation of the virus, and hence the potential target. The aim of this study is to repurpose the Food and Drug Administration (FDA) approved molecules via computer-aided drug designing against M^pro (PDB ID: 6Y2F) of SARS CoV-2 due to its high x-ray resolution of 1.95 Å as compared to other published M^prostructures. High Through Virtual Screening (HTVS) of 2456 FDA approved drugs using structure-based docking were analyzed. Molecular Dynamics simulations were performed to check the overall structural stability (RMSD), Cα fluctuations (RMSF) and protein-ligand interactions. Further, trajectory analysis was performed to assess the binding quality by exploiting the protein-residue motion cross correlation (DCCM) and binding free energy (MM/GBSA). Tenofovir, an antiretroviral for HIV-proteases and Terlipressin, a vasoconstrictor show stable RMSD, RMSF, better MM/GBSA with good cross correlation as compared to the Apo and O6K. Moreover, the results show concurrence with Nelfinavir, Lopinavir and Ritonavir which have shown significant inhibition in in vitro studies. Therefore, we conclude that Tenofovir and Terlipresssin might also show protease inhibition but are still open to clinical validation in case of SARS-CoV 2 treatment.Communicated by Ramaswamy H. Sarma.

Terlipressin has stood the test of time: Clinical overview in 2020 and future perspectives

Vasoactive drugs form the mainstay of therapy for two of the most important complications of liver disease: hepatorenal syndrome (HRS) and acute variceal bleed (AVB). With cumulative evidence supporting the use in cirrhosis, terlipressin has been recommended for the management of HRS and AVB. However, owing to the safety concerns, terlipressin was not approved by food and drug administration (FDA) until now. In this review, we discuss the pharmacology and the major practice-changing studies on the safety and efficacy of terlipressin in patients with cirrhosis particularly focusing on existing indications like AVB and HRS and reviewing new data on the expanding indications in liver disease. The references for this review were identified from PUBMED with MeSH terms such as "terlipressin," "hepatorenal syndrome," "varices, esophagal and gastric," "ascites" and "cirrhosis." Terlipressin, a synthetic analogue of vasopressin, was introduced in 1975 to overcome the adverse effects of vasopressin. Terlipressin is an effective drug for HRS reversal in patients with liver cirrhosis and acute-on-chronic liver failure. There is documented mortality benefit with terlipressin therapy in HRS and AVB. Adverse effects are common with terlipressin and need to be monitored strictly. There is some evidence to support the use of this drug in refractory ascites, hepatic hydrothorax, paracentesis-induced circulatory dysfunction and perioperatively during liver transplantation. However, terlipressin is not yet recommended for such indications. In conclusion, terlipressin has stood the test of time with expanding indications and clear prerequisites for clinical use. Our review warrants a fresh perspective on the efficacy and safety of terlipressin.

In vitro binding and receptor-mediated activity of terlipressin at vasopressin receptors V1 and V2

Terlipressin, a synthetic, systemic vasoconstrictor with selective activity at vasopressin-1 (V₁) receptors, is a pro-drug for the endogenous/natural porcine hormone [Lys₈]-vasopressin (LVP). We investigated binding and receptor-mediated cellular activities of terlipressin, LVP, and endogenous human hormone [Arg₈]-vasopressin (AVP) at V₁ and vasopressin-2 (V₂) receptors. Cell membrane homogenates of Chinese hamster ovary cells expressing human V₁ and V₂ receptors were used in competitive binding assays to measure receptor-binding activity. These cells were used in functional assays to measure receptor-mediated cellular activity of terlipressin, LVP, and AVP. Binding was measured by [³H]AVP counts, and the activity was measured by fluorometric detection of intracellular calcium mobilization (V₁) and cyclic adenosine monophosphate (V₂). Binding potency at V₁ and V₂ was AVP>LVP>>terlipressin. LVP and terlipressin had approximately sixfold higher affinity for V₁ than for V₂. Cellular activity potency was also AVP>LVP>>terlipressin. Terlipressin was a partial agonist at V₁ and a full agonist at V₂; LVP was a full agonist at both V₁ and V₂. The in vivo response to terlipressin is likely due to the partial V₁ agonist activity of terlipressin and full V₁ agonist activity of its metabolite, LVP. These results provide supportive evidence for previous findings and further establish terlipressin pharmacology for vasopressin receptors.

Impact of terlipressin infusion during and after live donor liver transplantation on incidence of acute kidney injury and neutrophil gelatinase-associated lipocalin serum levels: A randomized controlled trial

BACKGROUND AND AIM

Acute kidney injury (AKI) with liver transplantation (LT) is not uncommon. Impact of terlipressin infusion on AKI, hemodynamics, and plasma concentration of neutrophil gelatinase-associated lipocalin (NGAL) was studied.

METHODS

Patients (n=50) were randomized (NCT02059460, USA) into two equal groups: terlipressin vs Controls. Terlipressin (1-4 μg/kg/h) was administrated for 5 days. Intraoperative transesophageal Doppler for hemodynamic management. Renal functions, peak portal vein blood flow velocity (PPV), and hepatic artery resistive index (HARI) were recorded. Plasma NGAL (pNGAL) was measured baseline, 2 and 24 hours postreperfusion.

RESULTS

Hepatitis C virus (HCV) was the main etiology. Age, sex, model of end-stage liver disease (MELD), and renal functions were comparable. Postoperative AKI incidence and NGAL concentrations were comparable (P>.05) between terlipressin and controls groups (44% vs 48% and 112.5±9 vs 93.1±8 ng/mL), respectively, but intraoperative NGAL in both groups increased significantly 2 hours postreperfusion (P<.05). The three NGAL readings were comparable (P>.05) between AKI (n=23) and non-AKI developers (n=27). Mean arterial blood pressure (MAP) was maintained in both groups with less systemic vascular resistance (SVR) fluctuations with terlipressin. Median norepinephrine consumption was lower in terlipressin vs controls (8 vs 12 mg; P=.04). The PPV and HARI were not affected by terlipressin at any stage (P>.05).

CONCLUSION

Postliver transplant AKI was not prevented by terlipressin use nor predicted by NGAL levels.

Terlipressin Induced Severe Hyponatremia

Terlipressin is a vasopressin analogue used for its vasoconstrictor effect in the treatment of variceal bleeding. Despite its good safety profile compared to vasopressin, some adverse reactions may occur during its use - e.g. hyponatremia. We describe a case of a cirrhotic patient with active variceal bleeding treated during two separate hospitalizations with terlipressin. In both drug treatment periods, severe laboratory hyponatremia developed. After terlipressin discontinuation, mineral disbalance corrected rapidly. Positive dechallenge and rechallenge corresponding to the drug administration schedule confirms the causality between terlipressin administration and hyponatremia. Hyponatremia was preceded with substantial fluid retention in both episodes. In this case report we want to highlight the need for fluid balance monitoring immediately after first terlipressin dose, which may individually predict the patient risk for the development of hyponatremia as other risk factors have rather limited predictive value in real clinical settings.

[Hepatorenal syndrome: focus]

Hepatorenal syndrome (HRS) is a severe complication of cirrhosis. It develops as a result of abnormal hemodynamics, leading to systemic vasodilatation and renal vasoconstriction. Increased bacterial translocation, various cytokines and systemic inflammatory response system contribute to splanchnic vasodilatation, and altered renal autoregulation. An inadequate cardiac output with systolic incompetence increases the risk of renal failure. Type 1 HRS is usually initiated by a precipitating event associated with an exaggerated systemic inflammatory response, resulting in multiorgan failure. Vasoconstrictors are the basic treatment in patients with type 1 HRS; terlipressin is the superior agent. Norepinephrine can be used as an alternative. Transjugular intrahepatic portosystemic stent shunt may be applicable in a small number of patients with type 1 HRS and in most patients with type 2 HRS. Liver transplantation is the definitive treatment for HRS. The decision to do simultaneous or sequential liver and kidney transplant remains controversial. In general, patients who need more than 8 to 12 weeks of pretransplant dialysis should be considered for combined liver-kidney transplantation.

Recent advances in our understanding of hepatorenal syndrome

Hepatorenal syndrome (HRS) is a serious complication of advanced cirrhosis with ascites. HRS develops as a result of abnormal haemodynamics, leading to splanchnic and systemic vasodilatation, but renal vasoconstriction. Increased bacterial translocation, various cytokines and mesenteric angiogenesis also contribute to splanchnic vasodilatation, and altered renal autoregulation is involved in the renal vasoconstriction. Type 1 HRS is usually initiated by a precipitating event associated with an exaggerated systemic inflammatory response that perturbs haemodynamics, resulting in multiorgan failure. An inadequate cardiac output with systolic incompetence increases the risk of renal failure. Vasoconstrictors are the main treatment in patients with type 1 HRS; terlipressin is the superior agent. Norepinephrine is similar to terlipressin in efficacy and can be used as an alternative. Transjugular intrahepatic portosystemic stent shunt might be applicable in a small number of patients with type 1 HRS and in most patients with type 2 HRS. Liver transplantation is the definitive treatment for HRS, and should be performed after reversal of HRS. In nonresponders to vasoconstrictor therapy, much controversy still exists as to whether to do simultaneous or sequential liver and kidney transplant. In general, patients who have had >8-12 weeks of pretransplant dialysis should be considered for combined liver-kidney transplantation.

The use of terlipressin in cirrhotic patients with refractory ascites and normal renal function: a multicentric study

Ascites is a common complication of liver cirrhosis, occurring in more than 50-60% of the patients within 10 years of the diagnosis. In 5-10% of patients, ascites cannot be mobilized, or its early recurrence cannot be prevented by medical treatment. This condition is known as "refractory ascites". The use of terlipressin in cirrhotic patients with refractory ascites and normal renal function has not been evaluated. This prospective study was aimed at evaluating whether terlipressin in addition to standard therapy (diuretics plus albumin) might improve the outcome of refractory ascites in cirrhotic patients without HRS.

PATIENTS

26 cirrhotic patients with refractory ascites were prospectively enrolled in this study. All the patients had tense (grade 3) ascites, and 10/26 showed also massive peripheral edema. Patients received maximum diuretic treatment plus albumin and terlipressin.

RESULTS

Complete response was seen in 16/26 patients. The higher response to therapy was seen during the 2nd week of treatment. 6 patients showed a decrease of at least two points in the ascites score. No differences in clinical response to treatment were seen according to the etiology of the disease.

CONCLUSIONS

In conclusion, our study shows a synergistic effect of terlipressin vs treatment with albumin plus diuretics in patients with refractory ascites. One could speculate that albumin might enhance the vasoconstrictive response to terlipressin, thus contributing to counterbalance the negative effects of systemic vasodilation, which characterizes the hyperdynamic circulation of cirrhotic patients.

Differential effects of terlipressin on pulmonary and systemic hemodynamics in patients with cirrhosis and pulmonary hypertension: an echo study

Terlipressin has been associated with pulmonary arterial vasodilation in patients with pulmonary hypertension (PH). We investigated the effects of terlipressin on pulmonary vascular resistance (PVR) in patients with cirrhosis without and with PH. Pulmonary vascular resistance and cardiac output (CO) by Doppler ultrasound, mean arterial pressure (MAP), and systemic vascular resistance (SVR) were evaluated in patients with cirrhosis with PVR -120 dyne s cm⁻⁵ (group 1, n = 20) and PVR >120 dyne s cm⁻⁵ (group 2, n = 10) before and 30 minutes after terlipressin infusion (2 mg). After terlipressin, PVR increased significantly in group 1 (96.1 ± 20.2 vs 85.1 ± 18 dyne s cm⁻⁵; P = .004) but decreased significantly in group 2 (170.4 ± 37.8 vs 157.8 ± 28.1 dyne s cm⁻⁵; P= .04). Pulmonary vascular resistance changes in group 2 correlated significantly with baseline PVR (r = -0.632; P = .04). Terlipressin induced a significant increase in MAP and SVR and a significant decrease in CO in both groups. Terlipressin significantly reduces pulmonary pressures in patients with cirrhosis having PH together with systemic hemodynamic improvement.

Effects of terlipressin and somatostatin on liver and thorax blood volumes in patients with cirrhosis

BACKGROUND

Variceal bleeding in cirrhosis can cause liver ischaemia and deteriorate the hyperdynamic state; thus, the effects of vasoconstrictor therapy on liver blood volume (LBV) and thorax blood volume (ThBV) are important.

AIM

To evaluate and compare the effects of terlipressin and somatostatin on LBV and ThBV in stable patients with cirrhosis and portal hypertension.

METHODS

Twenty patients were studied (Child-Pugh class A/B/C: 5/8/7). The radioactivities in the liver region (LRR) and the thorax region (ThRR) by single-head gamma camera technique, as indicators of LBV and ThBV, respectively, and systemic haemodynamics were measured at baseline and after intravenous infusion of 2 mg of terlipressin (n=10) or somatostatin 250 mg/h after an initial bolus of 250 mg (n=10).

RESULTS

LRR and ThRR decreased significantly with increasing severity of cirrhosis. Thirty minutes after terlipressin infusion, LRR and ThRR increased by 7.8 ± 4.4% (NS) and 14 ± 5.3% (P=0.01) compared with baseline values; the increase in ThRR was significantly related to the increase in LRR (r=0.682, P=0.03). In contrast, somatostatin reduced LRR and ThRR by 13.3 ± 6.5% (P=0.07) and 1 ± 4% (NS) respectively. LRR and ThRR increased significantly in the terlipressin group compared with the somatostatin group (P=0.01 and P=0.02 respectively). Terlipressin reduced cardiac output and heart rate (both P=0.01) and increased the mean arterial pressure (MAP) and systemic vascular resistance (P=0.009 and P=0.002 respectively); MAP decreased after somatostatin infusion (P=0.03).

CONCLUSIONS

Terlipressin, but not somatostatin, maintains LBV, increases ThBV and improves the hyperdynamic state in cirrhosis. These effects can be beneficial in variceal bleeding, particularly in patients with advanced liver disease.

Terlipressin therapy for reversal of type 1 hepatorenal syndrome: a meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Hepatorenal syndrome (HRS) is a serious complication of advanced liver disease and carries a poor prognosis. Recent trials have indicated that terlipressin may be effective in reversing HRS. Our aim was to evaluate the efficacy of terlipressin therapy in reversing type 1 HRS defined as a serum creatinine <1.5 mg/dL during treatment.

METHODS

Randomized controlled trials in which patients with type 1 HRS received at least 3 days of terlipressin therapy and albumin in the intervention arm were included after a systematic search of the published English reports. Studies with other vasoconstrictor therapies in the control group were excluded.

RESULTS

A total of 223 patients with HRS type 1 in four different trials, were included in the final analysis. Alcohol-related cirrhosis was the most common underlying etiology. The risk ratio for reversal in type 1 HRS with terlipressin therapy was 3.66 (95% confidence interval 2.15-6.23). Recurrence of HRS was low (8%). Serious side-effects requiring discontinuation of therapy were seen only in 6.8% of patients on terlipressin therapy. There was a trend towards improved transplant-free survival at 90 days in the terlipressin group (relative risk 1.86 95% confidence interval 1.0-3.4, P = 0.05).

CONCLUSIONS

Terlipressin is effective in reversing HRS type 1. Recurrence of HRS is rare with at least 14 days of therapy. Serious side-effects requiring discontinuation of therapy are less common. There appears to be a survival benefit in patients with HRS treated with terlipressin.