Population pharmacokinetic model of canrenone after intravenous administration of potassium canrenoate to paediatric patients

Pharmacokinetics of oral spironolactone in infants up to 2 years of age

PURPOSE

Spironolactone is a potassium sparing diuretic used for decades. Until now, pharmacokinetic (PK) studies of spironolactone have not been conducted in infants and therefore pediatric dosing is based on expert opinion. We aimed to describe the PK profiles of spironolactone and its main metabolites (7alpha-thiomethylspironolactone (TMS) and canrenone (CAN)) in infants up to two years of age.

METHODS

The PK of spironolactone and its main metabolites were evaluated following an oral administration of spironolactone (1 mg/kg/dose) to pediatric patients with chronic heart failure, ascites, and/or oedema. The plasma concentration of spironolactone and metabolites (TMS and CAN) was determined using an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Based on rich sampling PK data, the estimation of population PK parameters was performed using nonlinear mixed-effects modelling software Monolix 2018R2.

RESULTS

A total of 150 spironolactone, 158 TMS, and 158 CAN concentrations from 23 patients (ages: 3 days-21 months; median weight 4.3 kg (2.2-12.6)) were available for PK analysis. A one-compartment model for spironolactone, TMS, and CAN best fitted the data. The median (range) of individual estimated apparent clearance values were 47.7 (11.9-138.1) L/h for spironolactone, 9.7 (1.5-66.9) L/h for TMS, and 1.0 (0.2-5.9) L/h for CAN. The disposition of spironolactone and metabolites was mainly affected by size of the patient: body weight explained 22% of inter-individual variability of spironolactone clearance. None of the undesirable effects of spironolactone was documented during the study period.

CONCLUSION

The pharmacokinetics of spironolactone and its metabolites was highly variable between patients below 2 years of age. Body weight explained a significant part of this variability; this highlights the need to take it into account for dosing prescription in this population. (Clinical trial Registration Number 2013-001189-40).

Potassium canrenoate in brain-dead organ donors: a randomised controlled clinical trial protocol (CANREO-PMO)

INTRODUCTION

Ischaemia/reperfusion injuries (IRIs) are associated with poorer survival of kidney grafts from expanded criteria donors. Preclinical studies have shown that mineralocorticoid receptor antagonists (MRAs) prevent acute and chronic post-ischaemic renal dysfunction by limiting IRI. However, data concerning the safety of MRAs in brain-dead donor patients are scarce. We seek to investigate the tolerance of MRAs on the haemodynamics in this population.

METHODS AND ANALYSIS

CANREO-PMO is a randomised, controlled, single-centre, double-blind study. Brain-dead organ donors hospitalised in intensive care are randomised 1:1 after consent to receive 200 mg potassium canrenoate or its matching placebo every 6 hours until organ procurement. The primary outcome is a hierarchical composite endpoint that includes: (1) cardiocirculatory arrest, (2) the impossibility of kidney procurement, (3) the average hourly dose of norepinephrine/epinephrine between randomisation and departure to the operating room, and (4) the average hourly volume of crystalloids and/or colloids received. Thirty-six patients will be included. The secondary endpoints evaluated among the graft recipients are the: (1) vital status of the kidney graft recipients and serum creatinine level with estimated glomerular filtration rate (GFR) according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) at 3 months after renal transplantation, (2) percentage of patients dependent on dialysis and/or with an estimated GFR <20 mL/min/1.73 m2 at 3 months, (3) vital status of the kidney graft recipients at 3 months, and (4) vital status of the kidney graft recipients and creatinine levels (in μmol/L), with the estimated GFR according to CKD-EPI (in mL/min/1.73 m2), at 1 year, 3 years and 10 years after transplantation.

ETHICS AND DISSEMINATION

This trial has full ethical approval (Comité de Protection des Personnes: CPP Ouest II-ANGERS, France), and the written consent of relatives will be obtained. Results will be reported at conferences, peer-reviewed publications and using social media channels.

TRIAL REGISTRATION NUMBER

NCT04714710.

Use of diuretics in the neonatal period

The use of diuretics is extremely frequent in sick neonates, the more so in very premature newborn infants. The use of diuretics in patients whose kidney function is immature necessitates a thorough knowledge of renal developmental physiology and pathophysiology. This review presents the basic aspects of body fluid homeostasis in the neonate, discusses the development of kidney function, and describes the mechanisms involved in electrolyte and water reabsorption along the nephron. Diuretics are then classified according to the site of their action on sodium reabsorption. The use of diuretics in sodium-retaining states, in oliguric states, in electrolyte disorders, and in arterial hypertension, as well as in a few specific disorders, is presented. Common and specific adverse effects are discussed. Recommended dosages for the main diuretics used in the neonatal period are given. New developments in diuretic therapy are briefly mentioned.