Terlipressin: vasopressin analog and novel drug for septic shock

FDA's stamp of approval: Unveiling peptide breakthroughs in cardiovascular diseases, ACE, HIV, CNS, and beyond

Peptides exhibit significant specificity and effective interaction with therapeutic targets, positioning themselves as key players in the global pharmaceutical market. They offer potential treatments for a wide range of diseases, including those that pose significant challenges. Notably, the peptide trofinetide (Daybue) marked a groundbreaking achievement by providing the first-ever cure for Rett syndrome, and several peptides have secured FDA approval as first-in-class medications. Furthermore, peptides are expanding their presence in areas traditionally dominated by either small or large molecules. A noteworthy example is the FDA approval of motixafortide (Aphexda) as the first peptide-based chemokine antagonist. Here, the focus will be on the analysis of FDA-approved peptides, particularly those targeting cardiovascular diseases, human immunodeficiency, central nervous system diseases, and various other intriguing classes addressing conditions such as osteoporosis, thrombocytopenia, Cushing's disease, and hypoglycemia, among others. The review will explore the chemical structures of the peptides, their indications and modes of action, the developmental trajectory, and potential adverse effects.

Efficacy and Safety of Terlipressin Infusion in Hepatorenal Syndrome-Acute Kidney Injury (HRS-AKI): A Retrospective Observational Study

Background Hepatorenal syndrome-acute kidney injury (HRS-AKI) is an event that occurs in chronic liver disease (CLD) and is associated with high morbidity and mortality. Terlipressin, a vasopressin analog, is used for the treatment of portal hypertension-related gastrointestinal (GI) bleeding and is found to be effective in the management of HRS-AKI. Continuous infusion of terlipressin maintains a high mean arterial pressure while reducing adverse events. It is better tolerated and equally effective at lower doses than intravenous boluses in patients with HRS-AKI. Aim of the study This study aimed to evaluate the safety and efficacy of terlipressin infusion at the rate of 4 mg/day in the treatment of HRS-AKI. Methods This retrospective study included patients who had HRS-AKI according to the modified International Club of Ascites (ICA) definition. Patients were started on a continuous intravenous infusion. The included patients received terlipressin 1 mg stat followed by a 4 mg infusion over 24 hours, and the infusion was continued until specific response criteria were met or for a maximum of seven days. Results In total, 136 patients were included in this study. The mean age of the study group was 45 years, the mean Child-Turcotte-Pugh (CTP) score was 11, the mean model for end-stage liver disease (MELD) score was 30, and the mean serum creatinine was 2.46 mg/dl. A response to treatment in the form of reduction of serum creatinine was observed in 94 (69.1%) patients, 30 (22%) patients showed no response, and worsening of creatinine was seen in 12 (8.8%) patients. The mean duration of hospital stay was 7.6 days, the mean serum creatinine was 1.17 mg/dl at the end of treatment, and the mean CTP and MELD scores in treatment responders were nine and 27, respectively. A total of 29 (21.3%) of 136 patients had adverse events during the terlipressin infusion therapy.  Conclusion Terlipressin infusion has sustained effects on splanchnic hemodynamics with fewer and less severe adverse events than intravenous bolus doses. Terlipressin infusion at a dose of 4 mg/day appeared to be well tolerated, with similar outcomes to that of 2 mg/day with a significantly lower albumin dose. These findings emphasize the importance of optimizing treatment protocols, particularly those favoring infusion methods, to enhance efficacy and minimize adverse effects.

Long-Circulating Vasoactive 1,18-Octadecanedioic Acid-Terlipressin Conjugate

Hepatorenal syndrome (HRS) is a life-threatening complication of end-stage liver disease first reported over a century ago, but its management still poses an unmet challenge. A therapeutic agent found to stabilize the condition is a short cyclic peptide, vasopressin analogue, terlipressin (TP). While TP is commonly prescribed for HRS patients in most parts of the world, it was only recently approved for use in the United States. TP exhibits short circulation half-lives and adverse side effects associated with the dose required. Herein, we present a 1,18-octadecanedioic acid (ODDA) conjugate of the cyclic peptide (ODDA-TP), which enables noncovalent binding to serum albumin via native fatty acid binding modes. ODDA-TP is demonstrated to outperform TP alone in studies including in vitro cellular receptor activation, stability in plasma, pharmacokinetics, and performance in vivo in rats. Specifically, ODDA-TP had an elimination half-life 20 times that of TP alone while exhibiting a superior safety profile.

Terlipressin for the Prevention and Treatment of Renal Decline in Hepatorenal Syndrome: A Drug Profile

Hepatorenal syndrome stands as one of several potential triggers of acute kidney injury in individuals grappling with either acute or persistent liver ailments. The nature of the decline in kidney function has led to the identification of two variants of hepatorenal syndrome. In cases where terlipressin therapy is accessible, the initial approach involves administering terlipressin alongside albumin. Terlipressin, a synthetic analog of vasopressin, boasts double the preference for vasopressin V1 receptors compared to V2 receptors. The FDA granted approval to terlipressin in September 2022, demonstrating its intrinsic activity, although a significant portion of its function arises from its transformation into lysine vasopressin. This article provides a comprehensive examination of terlipressin's various pharmacodynamic and pharmacokinetic facets, as well as its clinical utility, aiming to keep the scientific community well informed about its safe and efficient utilization.

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.

Synthesis and clinical application of new drugs approved by FDA in 2022

The pharmaceutical industry had a glorious year in 2022, with a total of 37 new drugs including 20 new chemical entities (NCEs) and 17 new biological entities (NBEs) approved by the Food and Drug Administration (FDA). These drugs are mainly concentrated in oncology, central nervous system, antiinfection, hematology, cardiomyopathy, dermatology, digestive system, ophthalmology, MRI enhancer and other therapeutic fields. Of the 37 drugs, 25 (68%) were approved through an expedited review pathway, and 19 (51%) were approved to treat rare diseases. These newly listed drugs have unique structures and new mechanisms of action, which can serve as lead compounds for designing new drugs with similar biological targets and enhancing therapeutic efficacy. This review aims to outline the clinical applications and synthetic methods of 19 NCEs newly approved by the FDA in 2022, but excludes contrast agent (Xenon Xe-129). We believe that an in-depth understanding of the synthetic methods of drug molecules will provide innovative and practical inspiration for the development of new, more effective, and practical synthetic techniques. According to the therapeutic areas of these 2022 FDA-approved drugs, we have classified these 19 NCEs into seven categories and will introduce them in the order of their approval for marketing.

Terlipressin in the management of liver disease

INTRODUCTION

Terlipressin is a synthetic vasopressin analog which has been recently approved in the United States by the Food and Drug Administration for the treatment of hepatorenal syndrome. Terlipressin stimulates vasopressin receptors located on the smooth muscle vasculature of the splanchnic circulation and renal tubules which results in splanchnic vasoconstriction with improved renal perfusion and antidiuretic activity, respectively.

AREAS COVERED

In this review, we discuss available data regarding the FDA approved use of terlipressin, safety, and tolerability, as well as highlight alternative uses in chronic liver disease currently still under investigation.

EXPERT OPINION

Terlipressin is more efficacious compared to other vasoactive agents including midodrine octreotide and norepinephrine in reversal of hepatorenal syndrome and improves short-term survival. Other potential applications of terlipressin's vasoconstrictor actions reported in the literature include management of variceal hemorrhage and other complications of portal hypertension.

2022 FDA TIDES (Peptides and Oligonucleotides) Harvest

A total of 37 new drug entities were approved in 2022; although that year registered the lowest number of drug approvals since 2016, the TIDES class consolidated its presence with a total of five authorizations (four peptides and one oligonucleotide). Interestingly, 23 out of 37 drugs were first-in-class and thus received fast-track designation by the FDA in categories such as breakthrough therapy, priority review voucher, orphan drug, accelerated approval, and so on. Here, we analyze the TIDES approved in 2022 on the basis of their chemical structure, medical target, mode of action, administration route, and common adverse effects.

Clinical characteristics and treatment of terlipressin-induced ischemic skin necrosis: A synthesis of 35 literature reported cases

WHAT IS KNOWN AND OBJECTIVE

The clinical features of terlipressin-induced ischemic skin necrosis are unknown. The purpose of this study is to explore the clinical features of terlipressin-induced skin necrosis.

METHODS

We searched Chinese and English databases to collect case reports of terlipressin-induced skin necrosis for retrospective analysis.

RESULTS AND DISCUSSION

A total of 42 patients (31 males and 11 females) from 35 studies were included, with a median age of 54 years (range 0.17-84). The onset of skin ischemia ranged from a few hours to 21 days. The most common clinical manifestations were bulla (15 cases, 35.7%), cyanosis (12 cases, 28.6%), necrosis (11 cases, 26.2%), and purpura (10 cases, 23.8%). The following were often affected: the legs (26 cases), 61.9%), abdomen (13, 31.0%), scrotum (10 cases, 23.8%), feet (10 cases, 23.8%), upper extremities (8 cases, 19.0%), and hands (7 cases, 16.7%). Skin biopsy showed fibrin thrombus (7 cases, 38.9%), nonspecific inflammation (6 cases, 33.3%), and necrosis (10 cases, 55.6%). After discontinuation of terlipressin, skin symptoms improved in most patients.

WHAT IS NEW AND CONCLUSION

Ischemic skin necrosis is a rare and serious adverse effect of terlipressin. Patients receiving terlipressin therapy should be monitored closely for terlipressin-related ischemic complications. Terlipressin should be discontinued immediately if ischemic complications occur.

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.

Pathophysiology and Prevention of Paracentesis-induced Circulatory Dysfunction: A Concise Review

Annually, 10% of cirrhotic patients with ascites develop refractory ascites for which large-volume paracentesis (LVP) is a frequently used therapeutic procedure. LVP, although a safe method, is associated with circulatory dysfunction in a significant percentage of patients, which is termed paracentesis-induced circulatory dysfunction (PICD). PICD results in faster reaccumulation of ascites, hyponatremia, renal impairment, and shorter survival. PICD is diagnosed through laboratory results, with increases of >50% of baseline plasma renin activity to a value ≥4 ng/mL/h on the fifth to sixth day after paracentesis. In this review, we discuss the pathophysiology and prevention of PICD.

Terlipressin infusion for prevention of vasoplegic syndrome in patients treated with angiotensin II receptor antagonist undergoing coronary artery bypass graft surgery: a randomized controlled study

Background and objectives

Preoperative use of renin angiotensin system antagonists has been considered an independent risk factor for development of vasoplegic syndrome. The aim of this study was to demonstrate efficacy of prophylactic terlipressin infusion for prevention of vasoplegic syndrome in patients treated with angiotensin receptor blocker undergoing coronary artery bypass graft surgery.

Patients and methods

One hundred patients on angiotensin II receptor antagonist [losartan] scheduled for coronary artery bypass surgery were enrolled into this prospective randomized controlled study. Anesthetic technique, surgical technique, and cardiopulmonary bypass management were standardized for all patients. With the start of rewarming, patients were randomized to receive either terlipressin infusion 1.3 μg.kg−1.hour−1, or normal saline infusion. Incidence of vasoplegic syndrome score was used as primary outcome. Hemodynamic parameters, inotropic score, and vasopressor dependency index were used as secondary outcome.

Results

Incidence of vasoplegic syndrome was significantly lower in terlipressin group compared to placebo group. Norepinephrine was required in 2 patients of terlipressin versus 15 patients of placebo group. Mean arterial blood pressure was significantly higher in terlipressin group compared to placebo group (81.7 ± 18.5 versus 69.3 ± 20.2 at 60 min after weaning from CBP). Cardiac index was significantly lower in terlipressin group compared to placebo group (2.52 ± 1.48 versus 3.2 ± 1.55). Systemic vascular resistance was significantly higher in terlipressin group compared to placebo group (2438.09 ± 735.13 versus 1575.05 ± 753.54). Inotropic score and vasopressor dependency index were significantly lower in terlipressin group compared to placebo group.

Conclusion

Prophylactic terlipressin infusion could prevent development of vasoplegic syndrome in patients treated with angiotensin II receptor antagonist undergoing coronary artery bypass graft surgery.

Trial registration

PACTR, PACTR201804003249274, Registered 25/03/2018—retrospectively registered, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=3249.

Terlipressin plus albumin for treatment of type 1 hepatorenal syndrome: A meta-analysis

AIM

to assess the efficacy of terlipressin plus albumin in the treatment of hepatorenal syndrome (HRS).

METHODS

Cochrane strategy was used to identify randomized controlled trials published before July 2016 by searching PubMed, The Cochrane Library, Web of Science and LILACS, Medline, EMBASE, Chinese Biomedical Literature Database, Chongqing VIP Information Co., Ltd, China National Knowledge Internet Database, and Wanfang Data.

RESULTS

Six randomized controlled trials involving 542 cases were selected for this meta-analysis. The HRS remission rate and the survival rate were increased by terlipressin plus albumin, with OR = 5.25 (95%CI: 2.77-6.52) and 2.33 (95%CI: 1.11-4.88) compared with albumin alone, respectively. Blood creatinine was decreased by the combination treatment, and mean arterial pressure was increased significantly, while there was no difference in urine output. Side effects due to systemic circulation congestion and peripheral vasoconstriction were reported, such as stomach ache and extremity cyanosis. No fatal side effect was reported.

CONCLUSION

compared with albumin alone, terlipressin plus albumin is effective in the treatment of HRS, as demonstrated by increased remission rate and survival rate and no occurrence of fatal side effect.

Vasoactive agents for the treatment of sepsis

The article describes some commonly used vasoactive agents in patients with septic shock. Depending on their distinct pharmacological properties, their effects on vascular bed and cardiac function are different. For example, dopamine has equivalent effect on heart and vasculature, which can result in increases in cardiac output, mean arterial pressure and heart rate. Dobutamine is considered as inodilator because it has potent effect on cardiac systole and vasculature. Patients with sepsis and septic shock sometimes have coexisting cardiac dysfunction that justifies the use of dobutamine. Levosimendan is a relatively new agent exerting its inodilator effect by increasing sensitivity of myocardium to calcium. Some preliminary studies showed a promising result of levosimendan on reducing mortality.

Vasopressin and its analogues for the treatment of refractory hypotension in neonates

BACKGROUND

Neonatal hypotension that is refractory to volume expansion, catecholamines, or corticosteroids has a mortality of about 50%. Optimization of blood pressure and tissue perfusion in refractory hypotension may be crucial to improve clinical outcomes. Vasopressin, a neuropeptide hormone, or its analogue terlipressin has been used to treat refractory hypotension in neonates and may be effective.

OBJECTIVES

Our primary objective was to evaluate the efficacy and safety of vasopressin and its synthetic analogues (e.g. terlipressin) in decreasing mortality and adverse neurodevelopmental outcomes, and improving survival in neonates with refractory hypotension. Our secondary objectives were to determine the effects of vasopressin and its analogues (terlipressin) on improvement in blood pressure, increase in urine output, decrease in inotrope score, necrotizing enterocolitis (NEC), periventricular leukomalacia, intraventricular hemorrhage, chronic lung disease, and retinopathy of prematurity (ROP) in neonates with refractory hypotension.

SEARCH METHODS

We searched the literature in January 2012, using the search strategy recommended by the Cochrane Neonatal Group. We searched electronic databases (CENTRAL (The Cochrane Library), MEDLINE, CINAHL, EMBASE), abstracts of the Pediatric Academic Societies, web sites for registered trials at www.clinicaltrials.gov and www.controlled-trials.com and in the reference list of identified articles.

SELECTION CRITERIA

Randomized or quasi-randomized trials evaluating vasopressin or its analogues, at any dosage or duration used as an adjunct to standard therapy (any combination of volume expansion, inotropic agents and corticosteroids) to treat refractory hypotension in neonates.

DATA COLLECTION AND ANALYSIS

We followed the standard methods of The Cochrane Collaboration for conducting a systematic review. Two review authors (BS and MP) independently assessed the titles and abstracts of studies identified by the search strategy for eligibility for inclusion. We obtained the full text version if eligibility could not be done reliably by title and abstract. We resolved any differences by mutual discussion. We designed electronic forms for trial inclusion/exclusion, data extraction, and for requesting additional published information from authors of the original reports.

MAIN RESULTS

Our search did not identify any completed or ongoing trials that met our inclusion criteria. Three studies that did not include neonates and one study where the objective was not to treat neonates with refractory hypotension were excluded.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend or refute the use of vasopressin or its analogues in the treatment of refractory hypotension in neonates. Well-designed, adequately powered, randomized controlled studies are necessary to address efficacy, optimal dosing, safety and long-term neurodevelopmental and pulmonary outcomes. 

Terlipressin in brain-death donors

BACKGROUND

Metabolic management of brain-death organ donors includes correction of the hormonal perturbations that occur after cerebral death and impair circulatory function. Vasopressin is a hormone secreted by the posterior pituitary gland, which contributes to maintain systemic blood pressure by regulating urine secretion and small arteriole tonus. During brain death, the pituitary gland is damaged and hormone secretion rapidly ceases. Low-dose vasopressin increases systemic blood pressure and decreases the need for catecholamines in brain-dead organ donors but it is not available in many countries. Terlipressin is a synthetic analog of vasopressin characterized by greater selectivity for the V1 receptor than vasopressin. To date, the efficacy of terlipressin as a pressor agent in humans has been reported in a few studies.

METHOD

Pharmacology and literature about the use of terlipressin in shock and in particularly in neurogenic shock following brain death is summarized and our personal experience is reported.

RESULTS AND CONCLUSION

Terlipressin is helpful in controlling severe hypotension; its use allowed to reduce the infusion rate of norepinephrine about 50% in two of three brain-death organ donors, but there are not yet enough data to define its therapeutic range and incidence of collateral effects on the grafts.

Effects of terlipressin on pulmonary artery pressure in a septic cooled infant: an echocardiographic assessment

Experience with terlipressin (TP) in the neonatal field is scarce. We describe the effects of TP on pulmonary circulation, studied with echocardiography, in an asphyxiated septic cooled infant with pulmonary hypertension (PH) who developed catecholamine-resistant hypotension and exacerbation of PH shortly after the beginning of the rewarming. TP was added to norephinephine and adrenaline infusions at the dose of 0.02 mg kg(-1) every 6 h, because of refractory hypotension and oliguria. After 10 min, blood pressure dramatically and definitely increased, and urinary output was re-established after 60 min. Echocardiographic evaluation 30 min after the second bolus of TP showed unchanged velocity of the tricuspidal valve regurgitation and improved biventricular functional indexes respect to the pre-treatment assessment. TP was continued for 12 h (three doses) without significant adverse effect except for a transient increase in troponin levels. Addition of TP boluses to catecholamine infusion in our newborn was effective in increasing systemic vascular resistance without increasing pulmonary vascular resistance, successfully reversing the hemodynamics of severe PH, and suggesting a potential primary vasodilator effect on pulmonary circulation. Transient increase of troponin levels during TP treatment confirms the risk of excessive coronary vasoconstriction when TP boluses are added to high dose catecholamines.

Rescue treatment with terlipressin in different scenarios of refractory hypotension in newborns and infants

OBJECTIVE

Terlipressin has been successfully used as rescue treatment in hypotensive adults and children with septic shock, but only exceptionally in neonates. The aim of this study is to describe original clinical scenarios in which terlipressin, in newborns and infants, resolved the catecholamine-refractory hypotension.

DESIGN

Retrospective study.

SETTING

Neonatal intensive care unit.

PATIENTS

All newborns with hypotension unresponsive to volume replacement and catecholamines, and treated with terlipressin, from January 2008 to December 2009. In this study, also an infant (11 months old) born extremely preterm was included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Four hypotensive patients received as rescue therapy terlipressin, which produced a dramatic increase in mean arterial pressure, diuresis, and reduction of lactate levels. In three newborns, hypotension, associated with pulmonary hypertension, was resolved with terlipressin. Two of them (one with systemic inflammatory response syndrome, the other with congenital diaphragmatic hernia) died in the following days for causes unrelated to hypotension; the third (on mild hypothermia for hypoxic-ischemic encephalopathy) recovered. We report furthermore an infant with septic shock and on treatment with β-blockers in whom terlipressin normalized blood pressure. In two patients, cranial Doppler ultrasonography showed the recovery of diastolic cerebral flow in the anterior cerebral artery and the normalization of resistance index within 30 mins from the first dose of terlipressin. In two infants, hyponatremia was detected.

CONCLUSION

Although the number of reported infants is little, terlipressin appears to be an effective rescue treatment in different scenarios of refractory neonatal hypotension. Further controlled studies are required to confirm its efficacy and safety.

Therapeutic response to vasoconstrictors in hepatorenal syndrome parallels increase in mean arterial pressure: a pooled analysis of clinical trials

BACKGROUND

Vasoconstrictor therapy has been advocated as treatment for hepatorenal syndrome (HRS). Our aim was to explore across all tested vasoconstrictors whether achievement of a substantial increase in arterial blood pressure is associated with recovery of kidney function in HRS.

STUDY DESIGN

Pooled analysis of published studies identified by electronic database search.

SETTING & POPULATION

Data pooled across 501 participants in 21 studies.

SELECTION CRITERIA FOR STUDIES

Human studies evaluating the efficacy of a vasoconstrictor administered for 72 hours or longer in adults with HRS type 1 or 2.

INTERVENTION

Vasoconstrictor therapy.

OUTCOMES & MEASUREMENTS

Cohorts' mean arterial pressure (MAP), serum creatinine level, urinary output, and plasma renin activity (PRA) at baseline and subsequent times during treatment. Linear regression models were constructed to estimate mean daily changes in MAP, serum creatinine level, urinary output, and PRA for each study subgroup. Correlations were used to assess for association between variables.

RESULTS

An increase in MAP is associated strongly with a decrease in serum creatinine level, but is not associated with an increase in urinary output. Associations were stronger when analyses were restricted to randomized clinical trials and were not limited to cohorts with either lower baseline MAP or lower baseline serum creatinine level. Most studies tested terlipressin as vasoconstrictor, whereas fewer studies tested ornipressin, midodrine, octreotide, or norepinephrine. Excluding cohorts of participants treated with terlipressin or ornipressin did not eliminate the association. Furthermore, a decrease in PRA correlated with improvement in kidney function.

LIMITATIONS

Studies were not originally designed to test our question. We lacked access to individual patient data.

CONCLUSIONS

An increase in MAP during vasoconstrictor therapy in patients with HRS is associated with improvement in kidney function across the spectrum of drugs tested to date. These results support consideration for a goal-directed approach to the treatment of HRS.

Bench-to-bedside review: Vasopressin in the management of septic shock

This review of vasopressin in septic shock differs from previous reviews by providing more information on the physiology and pathophysiology of vasopressin and vasopressin receptors, particularly because of recent interest in more specific AVPR1a agonists and new information from the Vasopressin and Septic Shock Trial (VASST), a randomized trial of vasopressin versus norepinephrine in septic shock. Relevant literature regarding vasopressin and other AVPR1a agonists was reviewed and synthesized. Vasopressin, a key stress hormone in response to hypotension, stimulates a family of receptors: AVPR1a, AVPR1b, AVPR2, oxytocin receptors and purinergic receptors. Rationales for use of vasopressin in septic shock are as follows: first, a deficiency of vasopressin in septic shock; second, low-dose vasopressin infusion improves blood pressure, decreases requirements for norepinephrine and improves renal function; and third, a recent randomized, controlled, concealed trial of vasopressin versus norepinephrine (VASST) suggests low-dose vasopressin may decrease mortality of less severe septic shock. Previous clinical studies of vasopressin in septic shock were small or not controlled. There was no difference in 28-day mortality between vasopressin-treated versus norepinephrine-treated patients (35% versus 39%, respectively) in VASST. There was potential benefit in the prospectively defined stratum of patients with less severe septic shock (5 to 14 μg/minute norepinephrine at randomization): vasopressin may have lowered mortality compared with norepinephrine (26% versus 36%, respectively, P = 0.04 within stratum). The result was robust: vasopressin also decreased mortality (compared with norepinephrine) if less severe septic shock was defined by the lowest quartile of arterial lactate or by use of one (versus more than one) vasopressor at baseline. Other investigators found greater hemodynamic effects of higher dose of vasopressin (0.06 units/minute) but also unique adverse effects (elevated liver enzymes and serum bilirubin). Use of higher dose vasopressin requires further evaluation of efficacy and safety. There are very few studies of interactions of therapies in critical care - or septic shock - and effects on mortality. Therefore, the interaction of vasopressin infusion, corticosteroid treatment and mortality of septic shock was evaluated in VASST. Low-dose vasopressin infusion plus corticosteroids significantly decreased 28-day mortality compared with corticosteroids plus norepinephrine (44% versus 35%, respectively, P = 0.03; P = 0.008 interaction statistic). Prospective randomized controlled trials would be necessary to confirm this interesting interaction. In conclusion, low-dose vasopressin may be effective in patients who have less severe septic shock already receiving norepinephrine (such as patients with modest norepinephrine infusion (5 to 15 μg/minute) or low serum lactate levels). The interaction of vasopressin infusion and corticosteroid treatment in septic shock requires further study.

New, potent, selective, and short-acting peptidic V1a receptor agonists

[Arg(8)]vasopressin (AVP) produces vasoconstriction via V(1a) receptor (V(1a)R)-mediated vascular smooth muscle cell contraction and is being used to increase blood pressure in septic shock, a form of vasodilatory hypotension. However, AVP also induces V(2) receptor (V(2)R)-mediated antidiuresis, vasodilation, and coagulation factor release, all deleterious in septic shock. The V(1a)R agonist terlipressin (H-Gly(3)[Lys(8)]VP) also lacks selectivity vs the V(2)R and has sizably longer duration of action than AVP, preventing rapid titration of its vasopressor effect in the clinic. We designed and synthesized new short acting V(1a)R selective analogues of general structure [Xaa(2),Ile(3),Yaa(4),Zaa(8)]VP. The most potent and selective compounds in in vitro functional assays (e.g., [Phe(2),Ile(3),Asn(Me(2))(4),Orn(8)]VP (31), [Phe(2),Ile(3),Asn((CH(2))(3)OH)(4),Orn(8)]VP (34), [Phe(2),Ile(3),Hgn(4),Orn(iPr)(8)]VP (45), [Phe(2),Ile(3),Asn(Et)(4),Dab(8)]VP (49), [Thi(2),Ile(3),Orn(iPr)(8)]VP (59), [Cha(2),Ile(3),Asn(4),Orn(iPr)(8)]VP (68)) were tested by intravenous bolus in rats for duration of vasopressive action. Analogues 31, 34, 45, and 49 were as short-acting as AVP. Compound 45, FE 202158, is currently undergoing clinical trials in septic shock.

Terlipressin in hepatorenal syndrome

OBJECTIVE

To compare the pharmacology, dosing, and adverse reactions of vasopressin and terlipressin for the treatment of hepatorenal syndrome (HRS) and assess the efficacy of the investigational drug terlipressin for HRS.

DATA SOURCES

Articles evaluating prospective studies for vasopressin and terlipressin were discussed after being identified through PubMed (1966-November 2010), International Pharmaceutical Abstracts (1970-November 2010), and EMBASE (1985-November 2010) with combinations of the following terms: vasopressin, terlipressin, and hepatorenal syndrome. In addition, reference citations from publications identified were reviewed. Thirteen studies were identified for terlipressin, along with 4 meta-analyses and 1 case report. For vasopressin, 2 studies were identified.

STUDY SELECTION AND DATA EXTRACTION

Prospective clinical studies directly comparing terlipressin and vasopressin were evaluated, as well as prospective clinical studies and meta-analyses for terlipressin in HRS.

DATA SYNTHESIS

No randomized, placebo-controlled trials using vasopressin for the treatment of type I HRS have been published, and 4 randomized studies involving 197 patients provide the most current outcome data for use of terlipressin in HRS. Terlipressin differs significantly from vasopressin with regard to its pharmacology, dosing, and adverse drug reaction profile. There is a paucity of data on vasopressin for HRS.

CONCLUSIONS

No definitive recommendations can be made for the use of terlipressin for this indication until further, well-conducted studies are performed.

Hepatorenal syndrome: a comprehensive overview for the critical care nurse

Over the past 50 years, the pathophysiology and features of the hepatorenal syndrome have been illuminated. The syndrome can be divided into 2 distinct clinical patterns: a rapidly progressive renal failure with an extremely poor prognosis (type 1) and a slow progressive renal failure that correlates with the degree of cirrhosis (type 2). Although our understanding of hepatorenal syndrome continues to grow, our current methods of treating this condition remain limited in their effectiveness. The only definitive therapy is liver transplantation. This is a review of the definition, pathophysiology, and current recommendations for management of hepatorenal syndrome with the critical care nurse in mind.

Terlipressin: a promising vasoactive agent in hemodynamic support of septic shock

BACKGROUND

At present, terlipressin is predominantly used for the management of bleeding gastric and esophageal varices, as well as hepato-renal syndrome secondary to liver cirrhosis. Owing to its high and relatively selective affinity to vascular V1 receptors, terlipressin is also increasingly used as an adjunct vasopressor agent in the management of vasodilatory hyperdynamic septic shock.

OBJECTIVE

This review article aims to summarize the available knowledge related to hemodynamic support with terlipressin in septic shock.

METHODS

For literature search, PubMed and specific keywords from the MeSH Database were used.

RESULTS/CONCLUSIONS

Terlipressin represents an effective pressor agent in patients with catecholamine-unresponsive septic shock. However, caution should be exercised, as terlipressin may contribute dose-dependently to vasoconstriction and a reflectory decrease in cardiac output. Additional studies are needed to clarify: i) the optimal time of therapy institution; ii) the efficacy and the dosages of continuous infusion versus bolus administration; and iii) the safety and efficacy of this compound in comparison with other nonspecific vasopressinergic drugs, such as arginine vasopressin. Whether or not terlipressin may improve the outcome of septic shock patients compared with standard therapy with catecholamines remains to be determined.

Detecting low-abundance vasoactive peptides in plasma: progress toward absolute quantitation using nano liquid chromatography-mass spectrometry

Profiling changes in the concentration of functionally related peptide hormones is critical to understanding the etiology of many diseases and therapies. We present novel data using nano liquid chromatography-mass spectrometry (LC-MS) to simultaneously measure a select group of vasoactive peptides (angiotensin, bradykinin, and related hormones) in 50-microl plasma samples, enabling repeated sampling in rodent models. By chromatographically resolving target peptides and using multiple reaction monitoring to enhance MS sensitivity, linear responses down to 10(-17) mol were achieved. Purification of plasma peptides by either methanol precipitation or off-line high-performance liquid chromatography (HPLC) fractionation enabled the detection of endogenous peptides and revealed approaches for enhancing recovery. As proof of principle, seven vasoactive peptides were profiled before, during, and after acute angiotensin-converting enzyme (ACE) inhibition in an anesthetized rat. Of note was an apparent 10-fold increase in vasodilatory bradykinin that reversed after drug infusion but relatively minor changes in angiotensin II levels. Targeted MS analysis used to profile functionally related peptides or other analytes will greatly enhance our ability to define the sequence of events regulating complex and dynamic physiological processes.

Role of arginine vasopressin and terlipressin as first-line vasopressor agents in fulminant ovine septic shock

PURPOSE

To compare the effects of first-line therapy with low-dose arginine vasopressin (AVP) or terlipressin (TP) on mesenteric blood flow, plasma AVP levels, organ function and mortality in ovine septic shock.

METHODS

Twenty-four adult ewes were anesthetized and instrumented for chronic hemodynamic monitoring. A flow-probe was placed around the superior mesenteric artery, and feces were extracted from the cecum. Following baseline measurements, feces were injected into the peritoneal cavity. When mean arterial pressure (MAP) decreased to less than 60 mmHg, animals were randomly assigned to receive AVP (0.5 mU kg(-1) min(-1)), TP (1 microg kg(-1) h(-1)) or saline (n = 8 each). A norepinephrine infusion was titrated to maintain MAP at 70 +/- 5 mmHg in all groups.

RESULTS

Cardiovascular pressures, cardiac output, mesenteric blood flow, and lung tissue concentrations of 3-nitrotyrosine and hemoxygenase-1 were similar among groups throughout the study period. TP infusion resulted in lower plasma AVP concentrations, reduced positive net fluid balance, increased central venous oxygen saturation and slightly prolonged survival compared to control and AVP-treated animals. However, TP treatment was associated with higher liver transaminases and lactate dehydrogenase versus control animals after 12 h.

CONCLUSIONS

This study provides evidence that the effects of low-dose TP differ from those of AVP, not only as TP has a longer half life, but also because of different mechanisms of action. Although low-dose TP infusion may be superior to sole norepinephrine or AVP therapy in septic shock, the safety of this therapeutic approach should be determined in more detail.

Terlipressin, a provasopressin drug exhibits direct vasoconstrictor properties: consequences on heart perfusion and performance

OBJECTIVE

Terlipressin has been proposed as an alternative treatment to catecholamines to restore blood pressure in septic shock. Terlipressin is considered as a vasopressin prodrug capable of releasing small but sustained amounts of [Lysine] vasopressin (LVP) and to provide prolonged biological effect. However, terlipressin may act as a direct vasopressor beyond its conversion into LVP. We investigated terlipressin direct vasoconstrictive properties and consequences on myocardial perfusion and performance.

DESIGN

Experimental studies.

SETTINGS

National Research Institute Laboratories.

SUBJECTS

Rat aorta and heart, human uterine artery.

INTERVENTIONS

Studies of vasoconstriction on isolated vascular rings obtained either from rat aorta or human uterine artery, and of coronary flow, ventricular performance, and heart rhythm on rat hearts using a modified Langendorff heart apparatus.

MEASUREMENTS AND MAIN RESULTS

Terlipressin induced a rapid, saturable, and dose-dependent contraction of rat aortas and human uterine arteries. Although the maximal terlipressin-induced vasoconstriction observed on rat arteries was weaker than LVP, or arginine-vasopressin, pharmacologic properties on human arteries, such as full agonism and strong maximal effect (900% of the maximal response obtained with phenylephrine), suggest a high potential of terlipressin to directly vasoconstrict human vessels. Similarly, terlipressin induced a saturable and dose-dependent vasoconstriction of coronary arteries that was reversible and antagonized by selective V1a antagonists. Maximum rates of left ventricle pressure rise (dP/dtmax) and fall (dP/dtmin) decreased both only in proportion to the decrease in coronary flow.

CONCLUSIONS

Besides long lasting effect through slow conversion into LVP, terlipressin is a fast acting vasopressor peptide per se that has an impact on coronary circulation and myocardial function.

Vasopressin vs. terlipressin in the treatment of cardiovascular failure in sepsis

BACKGROUND

Arginine vasopressin (AVP) and terlipressin (TP) are increasingly used as adjunct vasopressors in the treatment of septic shock. Despite important pharmacological differences between the two drugs (e.g., receptor selectivity, effective half-life) the use of either substance is determined mainly by local availability and institutional inventory. We briefly describe the pathophysiology and pharmacology of septic shock relevant to the treatment with vasopressin analogues. In addition, differences in pharmacokinetics and pharmacodynamics between AVP and TP are discussed.

DISCUSSION

The current literature suggests that neither AVP nor TP should be administered in high doses in patients with septic shock. Furthermore, increasing evidence indicates that early administration of vasopressin analogues may improve outcome as compared to a last-resort treatment. Low-dose infusion of AVP (0.6-2.4 U/h) has been demonstrated to be a safe adjunct in the management of septic shock. The V2 agonistic effects of AVP may exert favorable effects on hepatosplanchnic, renal, pulmonary, and coronary perfusion. However, the higher V1 receptor selectivity of TP may prove more potent in restoring arterial blood pressure and avoiding rebound hypotension, while carrying the risk of sustained global and regional vasoconstriction after bolus injection.

CONCLUSIONS

Evidence from experimental studies and initial clinical reports suggests that continuous low-dose infusion of TP may stabilize hemodynamics in septic shock with reduced side effects. However, randomized, controlled trials are necessary to determine the role of bolus or continuous infusion of TP in the treatment of septic shock before this approach can be recommended for routine clinical use.

Pharmacologic Interventions for the Management of Critical Bleeding

Hospital pharmacists are often consulted for their knowledge about coagulation and therapeutic interventions for the management of critical bleeding. Many pharmacotherapies are available for this purpose, both systemic and topical, and others are in development. These agents and their mechanisms of action are reviewed, and perspectives are provided regarding their use in various clinical settings. Also provided are associated precautions to promote safe use. Current controversies surrounding pharmacotherapeutic agents used to control serious bleeding (e.g., in various types of surgery, trauma, obstetrics, and intracranial hemorrhage) are also discussed.