Effect of the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan on the pharmacokinetics and pharmacodynamics of a single dose of furosemide

Bioanalytical HPLC method with fluorescence detector for determination of Entresto™ when co-administered with ibuprofen and fexofenadine: a pharmacokinetic study

Entresto™ (LCZ696) has been approved globally for heart failure management. However, its lifelong use alongside over-the-counter (OTC) drugs like ibuprofen (IBU) and fexofenadine (FEX) necessitates an in-depth investigation of potential pharmacokinetic interactions, as they share the same metabolic and elimination pathways. This study aimed to develop a bioanalytical HPLC method with a fluorescence detector (FLD) to quantify LCZ696 analytes (valsartan, VAL; sacubitril, SAC; and sacubitril active metabolite, LBQ657) in rat plasma. Additionally, an in vivo study was performed to investigate the pharmacokinetic interactions of LCZ696 with IBU and FEX. Utilizing HPLC with a gradient-mode mobile phase of acetonitrile and 0.025 M phosphate buffer (pH 3), the study demonstrated a significant increase in the bioavailability of LCZ696 analytes (VAL and LBQ657) when co-administered with IBU (C max 0.23 ± 0.07 and 0.53 ± 0.21 μg mL-1, respectively) compared to the control (0.17 ± 0.03 and 0.33 ± 0.14 μg mL-1). A more significant increase in C max was noticed with FEX (0.38 ± 0.01 and 0.77 ± 0.18 μg mL-1, respectively). Moreover, a decrease in the clearance (Cl/F) of VAL and LBQ657 was observed (18.05 ± 1.94 and 12.42 ± 2.97 L h-1 kg, respectively) with a more pronounced effect in the case of FEX (30.87 ± 4.29 and 33.14 ± 9.57 L h-1 kg, respectively) compared to the control (49.99 ± 7.31 and 51.19 ± 9.12 L h-1 kg, respectively). In conclusion, our study underscores the importance of cautious administration and appropriate dose spacing of IBU and FEX in patients treated with LCZ696 to prevent elevated serum concentrations and potential toxicity. The novelty of this work lies in its dual contribution: developing a highly sensitive HPLC-FLD method and comprehensively elucidating significant pharmacokinetic interactions between LCZ696 and common OTC drugs.

Effect of sacubitril/valsartan on brain natriuretic peptide level and prognosis of acute cerebral infarction

BACKGROUND AND PURPOSE

Previous studies demonstrated that elevated brain natriuretic peptide (BNP) level is associated with adverse clinical outcomes of acute cerebral infarction (ACI). Researchers hypothesized that BNP might be a potential neuroprotective factor against cerebral ischemia because of the antagonistic effect of the natriuretic peptide system on the renin-angiotensin system and regulation of cardiovascular homeostasis. However, whether decreasing the BNP level can improve the prognosis of ACI has not been studied yet. The main effect of sacubitril/valsartan is to enhance the natriuretic peptide system. We investigated whether the intervention of plasma BNP levels with sacubitril/valsartan could improve the prognosis of patients with ACI.

METHODS

In a randomized, controlled, parallel-group trial of patients with ACI within 48 hours of symptom onset and need for antihypertensive therapy, patients have randomized within 24 hours to sacubitril/valsartan 200mg once daily (the intervention group) or to conventional medical medication (the control group). The primary outcome was a change in plasma BNP levels before and after sacubitril/valsartan administration. The secondary outcomes included plasma levels of brain-derived neurotrophic factor (BDNF), Corin and neprilysin (NEP) before and after medication, the modified Rankin scale, and the National Institutes of Health Stroke Scale (at onset, at discharge, 30 days, and 90 days after discharge).

RESULTS

We evaluated 80 eligible patients admitted to the Stroke Center of Lianyungang Second People's Hospital between 1st May, 2021 and 31st June, 2022. Except for 28 patients excluded before randomization and 14 patients who did not meet the criteria or dropped out or lost to follow-up during the trial, the remaining 38 patients (intervention group: 17, control group: 21) had well-balanced baseline features. In this trial, we found that plasma BNP levels (P = 0.003) decreased and NEP levels (P = 0.006) increased in enrolled patients after treatment with sacubitril/valsartan. There were no differences in plasma BDNF and Corin levels between the two groups. Furthermore, no difference in functional prognosis was observed between the two groups (all P values>0.05).

CONCLUSIONS

Sacubitril/valsartan reduced endogenous plasma BNP levels in patients with ACI and did not affect their short-term prognosis.

Similarities and distinctions between acetazolamide and sodium-glucose cotransporter 2 inhibitors in patients with acute heart failure: Key insights into ADVOR and EMPULSE

Both acetazolamide and sodium-glucose cotransporter 2 (SGLT2) inhibitors block sodium reabsorption in the proximal renal tubule primarily through inhibition of sodium-hydrogen exchanger isoform 3 (NHE3), but neither SGLT2 inhibitors nor acetazolamide produce a sustained natriuresis due to compensatory upregulation of sodium reabsorption at distal nephron sites. Nevertheless, acetazolamide and SGLT2 inhibitors have been used as adjunctive therapy to loop diuretics in states where NHE3 is upregulated, e.g. acute heart failure. Two randomized controlled trials have been carried out with acetazolamide in acute heart failure (DIURESIS-CHF and ADVOR). In ADVOR, acetazolamide improved physical signs of fluid retention, but this finding could not be explained by the modest observed diuretic effect. Acetazolamide did not produce a natriuresis in the DIURESIS-CHF trial, and in ADVOR, immediate effects on symptoms and body weight were not reported, and the drug had no effect on morbidity or mortality after 90 days. Three randomized controlled trials have been carried out with empagliflozin (EMPAG-HF, EMPA-RESPONSE-AHF and EMPULSE) in acute heart failure. The EMPULSE trial did not report effects on diuresis or in changes in physical signs of congestion during the first week of treatment, but in EMPAG-HF and EMPA-RESPONSE-AHF, empagliflozin had no effect of dyspnoea, urinary sodium excretion or body weight during the first 4 days. In the EMPULSE trial, empagliflozin improved health status at 15 days and reduced the risk of worsening heart failure events at 90 days, but these effects are similar in magnitude and time course to the early statistical significance on the risk of heart failure hospitalizations achieved within 14-30 days in the major trials of SGLT2 inhibitors in patients with chronic heart failure. Neurohormonal inhibitors produce this early effect in the absence of a diuresis. Additionally, in numerous randomized controlled trials, in-hospital diuretic intensification has not reduced the risk of major heart failure events, even when treatment is sustained. These findings, taken collectively, suggest that any immediate diuretic effects of acetazolamide and SGLT2 inhibitors in acute heart failure are not likely to influence the short- or long-term clinical course of patients.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.

Development, validation, and implementation of an UHPLC-MS/MS method for the quantitation of furosemide in infant urine samples

Furosemide is a diuretic drug used to increase urine flow in order to reduce the amount of salt and water in the body. It is commonly utilized to treat preterm infants with chronic lung disease of prematurity. There is a need for a simple and reliable quantitation of furosemide in human urine. We have developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometry method for furosemide quantitation in human urine with an assay range of 0.100-50.0 μg/ml. Sample preparation involved solid-phase extraction with 10 μl of urine. Intra-day accuracies and precisions for the quality control samples were 94.5-106 and 1.86-10.2%, respectively, while inter-day accuracies and precision were 99.2-102 and 3.38-7.41%, respectively. Recovery for furosemide had an average of 23.8%, with an average matrix effect of 101%. Furosemide was stable in human urine under the assay conditions. Stability for furosemide was shown at 1 week (room temperature, 4, -20 and -78°C), 6 months (-78°C), and through three freeze-thaw cycles. This robust assay demonstrates accurate and precise quantitation of furosemide in a small volume (10 μl) of human urine. It is currently being implemented in an ongoing pediatric clinical study.

Contribution of Uptake and Efflux Transporters to Oral Pharmacokinetics of Furosemide

Furosemide is a widely used diuretic for treating excessive fluid accumulation caused by disease conditions like heart failure and liver cirrhosis. Furosemide tablet formulation exhibits variable pharmacokinetics (PK) with bioavailability ranging from 10 to almost 100%. To explain the variable absorption, we integrated the physicochemical, in vitro dissolution, permeability, distribution, and the elimination parameters of furosemide in a physiologically-based pharmacokinetic (PBPK) model. Although the intravenous PBPK model reasonably described the observed in vivo PK data, the reported low passive permeability failed to capture the observed data after oral administration. To mechanistically justify this discrepancy, we hypothesized that transporter-mediated uptake contributes to the oral absorption of furosemide in conjunction with passive permeability. Our in vitro results confirmed that furosemide is a substrate of intestinal breast cancer resistance protein (BCRP), multidrug resistance-associated protein 4 (MRP4), and organic anion transporting polypeptide 2B1 (OATP2B1), but it is not a substrate of P-glycoprotein (P-gp) and MRP2. We then estimated the net transporter-mediated intestinal uptake and integrated it into the PBPK model under both fasting and fed conditions. Our in vitro data and PBPK model suggest that the absorption of furosemide is permeability-limited, and OATP2B1 and MRP4 are important for its permeability across intestinal membrane. Further, as furosemide has been proposed as a probe substrate of renal organic anion transporters (OATs) for assessing clinical drug-drug interactions (DDIs) during drug development, the confounding effects of intestinal transporters identified in this study on furosemide PK should be considered in the clinical transporter DDI studies.

Plasma Trough Concentrations of Antihypertensive Drugs for the Assessment of Treatment Adherence: A Meta-Analysis

Supplemental Digital Content is available in the text.

Biochemical drug screening by liquid chromatography-tandem mass spectrometry in plasma is an accurate method for the quantification of plasma concentrations of antihypertensive medications in patients with hypertension. Trough concentrations could possibly be used as drug-specific cutoff values in the biochemical assessment of (non-)adherence. We performed a literature review and meta-analysis of pharmacokinetic studies to determine plasma trough concentrations of amlodipine, hydrochlorothiazide, and valsartan. PubMed was searched for pharmacokinetic studies up to September 2020. Eligible studies reported steady-state mean trough concentration and their variance. Pooled trough concentrations were estimated using a three-level random effects meta-analytic model. Moderator analyses were performed to explore sources of heterogeneity. One thousand three hundred eighteen potentially relevant articles were identified of which 45 were eligible for inclusion. The pooled mean trough concentration was 9.2 ng/mL (95% CI, 7.5–10.8) for amlodipine, 41.0 ng/mL (95% CI, 17.4–64.7) for hydrochlorothiazide, and 352.9 ng/mL (95% CI, 243.5–462.3) for valsartan. Substantial heterogeneity was present for all 3 pooled estimates. Moderator analyses identified dosage as a significant moderator for the pooled trough concentration of amlodipine (β₁=0.9; P<0.05), mean age, and mean body weight for the mean trough concentration of hydrochlorothiazide (β₁=2.2, P<0.05, respectively, β₁=−4.0, P<0.05) and no significant moderators for valsartan. Plasma trough concentrations of amlodipine, hydrochlorothiazide, and valsartan, measured with liquid chromatography-tandem mass spectrometry, are highly heterogeneous over the different studies. Use of the pooled trough concentration as a cutoff in the biochemical assessment of adherence can result in inaccurate diagnosis of (non-)adherence, which may seriously harm the patient-physician relationship, and is therefore not recommended.

A Pilot Study of the Maternal-Fetal Pharmacokinetics of Furosemide in Plasma, Urine, and Amniotic Fluid of Hypertensive Parturient Women Under Cesarean Section

The third trimester of pregnancy is related to physiological changes that can modify the process of absorption, distribution, metabolism, and excretion and, consequently, the efficacy and toxicity of drugs. However, little is known about furosemide pharmacokinetics and placental transfer in pregnancy. This study evaluated the maternal-fetal pharmacokinetics and distribution to amniotic fluid of furosemide in hypertensive parturient women under cesarean section. Twelve hypertensive parturient women under methyldopa (250 mg/8 h) and/or pindolol (10 mg/12 h) treatment received a 40-mg single oral dose of furosemide 1 to 10 hours before delivery by cesarean section. Blood and urine samples were collected for 12 hours after furosemide administration. At delivery, samples were obtained from maternal and umbilical cord blood (n = 8) to assess the transplacental transfer. Amniotic fluid (n = 4) was collected at the time of delivery. The following furosemide pharmacokinetic parameters were obtained as median (interquartile range): C_max , 403 ng/mL (229 to 715 ng/mL); T_max , 2.00 hours (1.50 to 4.83 hours); elimination half-life (t_1/2 ), 2.50 hours (1.77 to 2.97 hours); AUC_{0-12 h} , 1366 ng⋅h/mL (927 to 2531 ng⋅h/mL); AUC_0-∞ , 1580 ng⋅h/mL (1270 to 2881 ng⋅h/mL); CL/F 25.3 L/h (13.8 to 31.4 L/h); CLR, 2.50 L/h (1.77 to 2.97 L/h); CLNR, 22.7 L/h (12.1 to 25.6 L/h); and V_d /F 82.8 L (34.4 to 173 L). The transplacental transfer of furosemide was 0.43 (0.10 to 0.73), and the amniotic fluid concentration was 11.0 ng/mL (5.51 to 14.6 ng/mL). From a clinical point of view, these results suggest that substrates of uridine diphosphate-glucuronosyltransferase isoenzymes such as furosemide may have increased clearance during pregnancy and could require dose adjustment in this population.

Sacubitril-Valsartan in a routine community population: attention to volume status critical to achieving target dose

AIMS

In the PARADIGM-heart failure trial, sacubitril-valsartan demonstrated a reduction in heart failure admissions and reduced all-cause mortality in patients with heart failure with reduced ejection fraction. Although real world data have shown similar benefits regarding efficacy and safety, there has been difficulty in achieving the target dose (TD). The factors preventing the achievement of TD remains unclear. This study assesses the tolerability, ability to achieve, and factors linked to attaining TD in a routine clinical population.

METHODS AND RESULTS

This is a retrospective single-centre review of patients switched from angiotensin-converting enzyme inhibitors/angiotensin receptor blockers to sacubitril-valsartan between May 2016 and August 2018. Baseline and follow-up clinical characteristics and biomarker profiles were collected. Univariate and multivariate analyses were used to analyse predictors of achieving TD. Clinical response to sacubitril-valsartan was defined as a reduction in N terminal pro BNP of ≥30%, or an increase in left ventricular ejection fraction of ≥5% compared with baseline values. To date, a total of 322 patients (75% male patients) have been switched to sacubitril-valsartan. Those still in the titration phase were excluded (n = 25). Sacubitril-valsartan was not tolerated in 40 patients (12.4%). Those intolerant were older (73.4 years [68.3, 80.6] vs. 69.1 years [61.2, 76]; P = 0.003) and had worse renal function with estimated glomerular filtration rate (53.5 mL/min/1.72 m² [36.8, 60.2] vs 60 mL/min/1.72 m² [47, 77]; P ≤ 0.001). Of the remaining 257 patients, TD (97/103 mg BD) was achieved in 194 patients (75.5%), while 37 patients (11.4%) were maintained on 49/51 mg BD and 26 patients (8.1%) remained on 24/26 mg BD. Symptomatic hypotension (74.6%) was the main impediment to attaining TD, followed by renal deterioration (12.7%), and to a lesser extent hyperkalaemia and gastrointestinal symptoms (4.8% each). Diuretic dose decrease was achieved in 37.2% of patients, and this was the strongest independent predictor of achieving TD (odds ratio = 2.1; 95% confidence interval [1.16, 3.8]; P = 0.014). Responder status by N terminal pro BNP criterion was observed in 99 of 214 patients (46.3%) while 70 of 142 (49.3%) attained the left ventricular ejection fraction response status. Achieving this response was independently linked to achieving TD.

CONCLUSIONS

Sacubitril-valsartan was well tolerated. Achievement of TD was possible in the majority of the cohort and was linked to response metrics. Reduction in diuretic was required in a large percentage of the population and was the strongest predictor of attaining TD. Therefore, careful clinical attention to volume status assessment is essential to maximising the benefits of sacubitril-valsartan.

A prospective, randomized, double-blind, placebo-controlled pilot study of sacubitril/valsartan (Entresto) in dogs with cardiomegaly secondary to myxomatous mitral valve disease

Background

The effects of sacubitril/valsartan (S/V) on the renin‐angiotensin‐aldosterone system (RAAS) in dogs with cardiomegaly secondary to myxomatous mitral valve disease (MMVD) are currently unknown.

Objectives

To determine the pharmacodynamic effects of S/V on the RAAS, natriuretic peptide concentrations, systolic arterial pressure (SAP), tests of renal function, and serum electrolyte concentrations in dogs with cardiomegaly secondary to MMVD.

Animals

Thirteen client‐owned dogs weighing 4‐15 kg with American College of Veterinary Internal Medicine (ACVIM) Stage B2 MMVD.

Methods

Prospective, randomized, double‐blind, placebo‐controlled pilot study of S/V in dogs with ACVIM Stage B2 MMVD.

Results

Thirteen dogs were recruited: S/V (n = 7) and placebo (n = 6). The median percentage increase in urinary aldosterone to creatinine ratio (UAldo : C) between day 0 and day 30 was significantly lower in the S/V group (12%; P = .032) as compared with the placebo group (195%). The median percentage decrease of NT‐proBNP concentration from day 0 to day 30 was not statistically different between groups (P = .68). No statistical differences were seen in echocardiographic, thoracic radiographic, SAP, or serum biochemical test results measured at any time point between groups. No adverse events were observed for dogs in either group.

Conclusion and Clinical Importance

Sacubitril/valsartan may provide a new pharmaceutical method to effectively inhibit the RAAS in dogs with ACVIM Stage B2 MMVD.

Effect of the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan on the pharmacokinetics and pharmacodynamics of a single dose of furosemide

Aims

Sacubitril/valsartan is indicated for the treatment of heart failure and reduced ejection fraction (HFrEF). Furosemide, a loop diuretic commonly used for the treatment of HFrEF, may be coadministered with sacubitril/valsartan in clinical practice. The effect of sacubitril/valsartan on the pharmacokinetics and pharmacodynamics of furosemide was evaluated in this open label, two‐period, single‐sequence study in healthy subjects.

Methods

All subjects (n = 28) received 40 mg oral single‐dose furosemide during period 1, followed by a washout of 2 days. In period 2, sacubitril/valsartan 200 mg (97/103 mg) was administered twice daily for 5 days and a single dose of 40 mg furosemide was coadministered on day 6. Serial plasma and urine samples were collected to determine the pharmacokinetics of furosemide and sacubitril/valsartan and the pharmacodynamics of furosemide. The point estimates and the associated 90% confidence intervals for pharmacokinetic parameters were evaluated.

Results

Coadministration of furosemide with sacubitril/valsartan decreased the maximum observed plasma concentration (C_max) [estimated geometric mean ratio (90% confidence interval): 0.50 (0.44, 0.56)], area under the plasma concentration–time curve (AUC) from time 0 to infinity [0.72 (0.67, 0.77)] and 24‐h urinary excretion of furosemide [0.74 (0.69, 0.79)]. When coadministered with sacubitril/valsartan, 0–4‐h, 4–8‐h and 0–24‐h diuresis in response to furosemide was reduced by ~7%, 21% and 0.2%, respectively, while natriuresis was reduced by ~ 28.5%, 7% and 15%, respectively. Post hoc analysis of the pivotal phase III Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure trial (PARADIGM‐HF) indicated that the median furosemide dose was similar at baseline and at the end of the study in the sacubitril/valsartan group.

Conclusions

Sacubitril/valsartan reduced plasma C_max and AUC and 24‐h urinary excretion of furosemide, while not significantly affecting its pharmacodynamic effects in healthy subjects.