Initial effect of enalapril on kidney function in patients with moderate to severe chronic nephropathy

Enalapril and Enalaprilat Pharmacokinetics in Children with Heart Failure Due to Dilated Cardiomyopathy and Congestive Heart Failure after Administration of an Orodispersible Enalapril Minitablet (LENA-Studies)

Angiotensin-converting enzyme inhibitors (ACEI), such as enalapril, are a cornerstone of treatment for pediatric heart failure which is still used off-label. Using a novel age-appropriate formulation of enalapril orodispersible minitablets (ODMTs), phase II/III open-label, multicenter pharmacokinetic (PK) bridging studies were performed in pediatric patients with heart failure due to dilated cardiomyopathy (DCM) and congenital heart disease (CHD) in five participating European countries. Children were treated for 8 weeks with ODMTs according to an age-appropriate dosing schedule. The primary objective was to describe PK parameters (area under the curve (AUC), maximal concentration (Cmax), time to reach maximal concentration (t-max)) of enalapril and its active metabolite enalaprilat. Of 102 patients, 89 patients (n = 26, DCM; n = 63 CHD) were included in the primary PK endpoint analysis. Rate and extent of enalapril and its active metabolite enalaprilat were described and etiology and age could be identified as potential PK modifying factors. The dosing schedule appeared to be tolerated well and did not result in any significant drug-related serious adverse events. The PK analysis and the lack of severe safety events supports the applied age-appropriate dosing schedule for the enalapril ODMTs.

Clinical Pharmacokinetics of Enalapril and Enalaprilat in Pediatric Patients-A Systematic Review

Purpose: Enalapril has an established safety and efficacy in adults and is used in hypertension, heart failure, and renal failure. In pediatric patients, enalapril is labeled for children with hypertension and used off label in children with heart failure. The systematic literature search aims to assess the current knowledge about enalapril and its active metabolite enalaprilat pharmacokinetics in children as a basis for dose delineation for pediatric patients with heart failure. Methods: A systematic literature review was performed in the PubMed database using relevant keywords. Dose normalization of relevant pharmacokinetic parameters of the identified studies was done for comparison between different diseases and pediatric age groups. Results: The literature search has resulted in three pediatric pharmacokinetic studies of enalapril out of which Wells et al. reported about children with hypertension and Nakamura et al., and Llyod et al. presented data for pediatric heart failure patients. The area under the curve values of enalaprilat in hypertensive pediatric patients increased with respect to the age groups and showed maturation of body functions with increasing age. Dose normalized comparison with the heart failure studies revealed that although the pediatric heart failure patients of > 20 days of age showed the area under the curve a similar to that of hypertensive patients, two pediatric patients of very early age (<20 days) were presented with 5-6-fold higher area under the curve values. Conclusion: Data related to the pharmacokinetics of enalapril and enalaprilat in hypertensive patients and few data for young heart failure children are available. Comparison of dose normalized exposition of the active metabolite enalaprilat indicated similarities between heart failure and hypertensive patients and a potentially high exposition of premature patients but substantially more pharmacokinetic studies are required to have reliable and robust enalapril as well as enalaprilat exposures especially in pediatric patients with heart failure as a basis for any dose delineation.

Long-Term Effects of High-Protein Diets on Renal Function

Chronic kidney disease (CKD) has a prevalence of approximately 13% and is most frequently caused by diabetes and hypertension. In population studies, CKD etiology is often uncertain. Some experimental and observational human studies have suggested that high-protein intake may increase CKD progression and even cause CKD in healthy people. The protein source may be important. Daily red meat consumption over years may increase CKD risk, whereas white meat and dairy proteins appear to have no such effect, and fruit and vegetable proteins may be renal protective. Few randomized trials exist with an observation time greater than 6 months, and most of these were conducted in patients with preexisting diseases that dispose to CKD. Results conflict and do not allow any conclusion about kidney-damaging effects of long-term, high-protein intake. Until additional data become available, present knowledge seems to substantiate a concern. Screening for CKD should be considered before and during long-term, high-protein intake.

Beneficial effects on arterial stiffness and pulse-wave reflection of combined enalapril and candesartan in chronic kidney disease--a randomized trial

Background

Cardiovascular disease (CVD) is highly prevalent in patients with chronic kidney disease (CKD). Inhibition of the renin-angiotensinsystem (RAS) in hypertension causes differential effects on central and brachial blood pressure (BP), which has been translated into improved outcome. The objective was to examine if a more complete inhibition of RAS by combining an angiotensin converting enzyme inhibitor (ACEI) and an angiotensin receptor antagonist (ARB) compared to monotherapy has an additive effect on central BP and pulse-wave velocity (PWV), which are known markers of CVD.

Methods

Sixty-seven CKD patients (mean GFR 30, range 13–59 ml/min/1.73 m²) participated in an open randomized study of 16 weeks of monotherapy with either enalapril or candesartan followed by 8 weeks of dual blockade aiming at a total dose of 16 mg candesartan and 20 mg enalapril o.d. Pulse-wave measurements were performed at week 0, 8, 16 and 24 by the SphygmoCor device.

Results

Significant additive BP independent reductions were found after dual blockade in aortic PWV (−0.3 m/s, P<0.05) and in augmentation index (−2%, P<0.01) compared to monotherapy. Furthermore pulse pressure amplification was improved (P<0.05) and central systolic BP reduced (−6 mmHg, P<0.01).

Conclusions

Dual blockade of the RAS resulted in an additive BP independent reduction in pulse-wave reflection and arterial stiffness compared to monotherapy in CKD patients.

Trial Registration

Clinical trial.gov NCT00235287

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for adults with early (stage 1 to 3) non-diabetic chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a long term condition that occurs as a result of damage to the kidneys. Early recognition of CKD is becoming increasingly common due to widespread laboratory estimated glomerular filtration rate (eGFR) reporting, raised clinical awareness, and international adoption of Kidney Disease Outcomes Quality Initiative (K/DOQI) classification. Early recognition and management of CKD affords the opportunity not only to prepare for progressive kidney impairment and impending renal replacement therapy, but also for intervening to reduce the risk of progression and cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are two classes of antihypertensive drugs that act on the renin-angiotensin-aldosterone system. Beneficial effects of ACEi and ARB on renal outcomes and survival in people with a wide range of severity of renal impairment have been reported; however, their effectiveness in the subgroup of people with early CKD (stage 1 to 3) is less certain.

OBJECTIVES

This review aimed to evaluate the benefits and harms of ACEi and ARB or both in the management of people with early (stage 1 to 3) CKD who do not have diabetes mellitus.

SEARCH STRATEGY

In March 2010 we searched The Cochrane Library, including The Cochrane Renal Group's specialised register and The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Reference lists of review articles and relevant studies were also checked. The search was conducted using the optimally sensitive strategy developed by the Cochrane Collaboration for the identification of randomised controlled trials (RCTs) with input from an expert in trial search strategy.

SELECTION CRITERIA

All RCTs reporting the effect of ACEi or ARB in people with early (stage 1 to 3) CKD who did not have diabetes mellitus were selected for inclusion. Only studies of at least four weeks duration were selected. Authors, working in teams of two, independently assessed the retrieved titles and abstracts, and whenever necessary the full text of these studies were screened to determine which studies satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out by two authors, independently, using a standard data extraction form and cross checked by two other authors. Methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross checked by another author. When more than one study reported similar outcomes, data were pooled using the random-effects model, but a fixed-effect model was also analysed to ensure the robustness of the model chosen and to check susceptibility to outliers. Heterogeneity was analysed using a Chi² test on N-1 degrees of freedom, with an alpha of 0.05 used for statistical significance and with the I² test. Where data permitted, subgroup analysis was used to explore possible sources of heterogeneity. The quality of the evidence was analysed.

MAIN RESULTS

Four RCTs enrolling 2177 participants met our inclusion criteria. Of these, three compared ACEi with placebo and one compared ACEi with ARB. Two studies had an overall low risk of bias, and the other two were considered to be at moderate to high risk of bias. Low to moderate quality of evidence (from two studies representing 1906 patients) suggested that ACEi had no impact on all-cause mortality (RR 1.80, 95% CI 0.17 to 19.27, P = 0.63) or cardiovascular events (RR 0.87, 95% CI 0.66 to 1.14, P = 0.31) in people with stage 3 CKD. For all-cause mortality, there was substantial heterogeneity in the results. One study (quality assessment: low risk of bias) reported no difference in the risk of end-stage kidney disease in those with an eGFR > 45 mL/min/1.74 m² treated with ACEi versus placebo (RR 1.00, 95% CI 0.09 to 1.11, P = 0.99). The (high risk of bias) study that compared ACEi with ARB reported little difference in effect between the treatments when urinary protein, blood pressure or creatinine clearance were compared. No published studies comparing ARB with placebo or ACEi and ARB with placebo were identified.

AUTHORS' CONCLUSIONS

Our review demonstrated that there is currently insufficient evidence to determine the effectiveness of ACEi or ARB in patients with stage 1 to 3 CKD who do not have diabetes mellitus. We have identified an area of significant uncertainty for a group of patients who account for most of those labelled as having CKD.

Feasibility of combined treatment with enalapril and candesartan in advanced chronic kidney disease

BACKGROUND

Dual blockade of the renin-angiotensin system (RAS) has been claimed to have a specific renal protective effect in chronic kidney disease (CKD). The present short-term study reports on the feasibility of dual blockade in a consecutive group of patients with CKD stage 3-5.

METHODS

Forty-seven CKD patients, mean age 59 years, with mean estimated glomerular filtration rate (GFR) 26 ml/min/1.73 m(2) (range 13-49) and blood pressure (BP) 133/78 mmHg, were block randomized in an open study to 16 weeks of monotherapy with increasing doses of RAS blockade aiming at enalapril 20 mg o.d. or candesartan 16 mg o.d. Thereafter, the complementary drug was added in incremental doses over a period of 5 weeks aiming at combined enalapril 20 mg and candesartan 16 mg for 3 weeks. Seventy-five percent of the patients were known to be RAS blockade tolerant. Blood samples and BP were measured every 2-3 weeks. Doses of study medication were reduced in case of hyperkalemia >5.5 mmol/l, a sustained rise in p-creatinine >30% or symptomatic hypotension.

RESULTS

Twenty-one patients (45%) did not tolerate dual blockade in aimed dosages due to unacceptable p-creatinine increase (n = 12, including two study withdrawals), hypotension (n = 6), general discomfort (n = 2) or unmanageable hyperkalemia (n = 1). Hyperkalemia >5.5 mmol/l was seen in seven patients (15%). The reduced-dose group had baseline lower eGFR and diastolic BP.

CONCLUSIONS

Forty-five percent of CKD stage 3-5 patients did not tolerate dual RAS blockade with 20 mg enalapril and 16 mg candesartan daily, primarily due to loss of renal function or hypotension. Hyperkalemia could be managed in most patients. Caution is recommended when giving this treatment to patients with advanced CKD.

Blood pressure response to conventional and low-dose enalapril in chronic renal failure

AIMS

In chronic renal failure, the clearance of most ACE inhibitors including enalapril is reduced. Hence, with conventional dosage, plasma enalaprilat may be markedly elevated. It is unclear whether this excess of drug exposure affords an improved control of blood pressure. The aim of the present study was to evaluate short-term blood pressure response to two different plasma levels of enalaprilat.

METHODS

As part of an open, randomized, controlled trial of the effect of high and low dosage of enalapril on the progression of renal failure, short-term blood pressure response was evaluated. Data were analysed in all patients completing 3 months of follow-up. The patients were allocated to two trough plasma concentrations of enalaprilat, either above 50 ng ml(-1) (high) (n = 17) or below 10 ng ml(-1) (low) (n = 18), and the daily dose of enalapril titrated accordingly.

RESULTS

Median (range) glomerular filtration rate (GFR) at baseline was 18 (7.9) in the high enalaprilat concentration group and 17 (7.3) ml min(-1) 1.73 m(2) in the low concentration group (NS). Nine patients in each group were on treatment with enalapril at baseline with a median daily dose of 5 mg in both the high (5-10) and low (2.5-20) concentration group. At 3 months' follow-up, the dose was 10 (2.5-30) and 1.9 (1.25-5) mg (P < 0.0001), respectively. After 3 months median trough concentrations of enalaprilat were 82.5 (22-244) ng ml(-1) and 9.1 (2.5-74.8) ng ml(-1) (P < 0.002). At baseline the median systolic blood pressures in the two groups were 140 (110-200) and 133 (110-165), in the high and low enalaprilat concentration groups, respectively, and after 3 months they were 135 (105-170) and 130 (105-170) mmHg (NS). Median diastolic blood pressure was 80 mmHg in each group both at baseline (65-100) and at follow-up (60-95) (NS). There was no difference between the groups in concomitant antihypertensive treatment (number of patients treated, mean daily dose) during the observation period. Proteinuria remained stable during the study period in both groups; patients in the high concentration group had higher plasma potassium concentrations at day 90 and patients in the low group experienced a slight increase in GFR.

CONCLUSIONS

In moderate to severe chronic renal insufficiency the same degree of blood pressure control was achieved on low as well as moderate daily doses of enalapril. This was irrespective of concomitant antihypertensive treatment.

ACE inhibition preserves renal function better than beta-blockade in the treatment of essential hypertension

Antihypertensive treatment can slow down the decline in glomerular filtration rate (GFR) with time. In patients with diabetic nephropathy, angiotensin converting enzyme (ACE) inhibition has been shown to be more effective in this regard than conventional antihypertensive therapy. Whether this applies to the much larger population of patients with essential hypertension is not yet known. In the present study, the effects of two different antihypertensive therapies on the loss of GFR with time, determined with Cr51-EDTA clearance after 6, 12 and 24 months of treatment, were assessed in a prospective, randomised, double-blind trial in 257 patients with essential hypertension. All had normal renal function and none had diabetes mellitus or glucosuria. Proteinuria (dipstick positive or trace) was detected in 7 patients initially. The two therapeutic modalities were the ACE inhibitor cilazapril and the beta-adrenoceptor blocking agent atenolol. Both therapies were equally effective in lowering systolic blood pressure (e.g. from 168 mmHg to 152 mmHg with cilazapril and from 170 mmHg to 155 mmHg with atenolol after 6 months, p < 0.001 for both). However, atenolol was slightly but significantly more effective in lowering the diastolic blood pressure at 6, 12 and 24 months. The decline in GFR with time was significantly smaller with cilazapril than with atenolol. After 6 months the reduction in GFR was 1.0 vs. 4.0 ml/min x 1.73 m2, p = 0.008 (cilazapril vs. atenolol) and after 12 months the corresponding changes were 2.0 vs. 4.5 ml/min x 1.73 m2, p = 0.04 and after 24 months 3.0 vs. 4.0 ml/min x 1.73 m2, respectively (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-converting enzyme inhibitors in diabetic nephropathy

OBJECTIVE

Diabetic nephropathy (DN) is a leading cause of kidney disease in the US. At least four factors influence whether people with diabetes will develop DN: (1) hypertension, (2) hyperglycemia, (3) dietary protein intake, and (4) intrarenal hemodynamics. The angiotensin-converting enzyme (ACE) inhibitors are known to affect blood pressure (BP) and intrarenal hemodynamics; thus, they may prevent the onset of DN or slow the decline in renal function once DN has been diagnosed.

DATA SOURCES

English-language, controlled, and crossover studies published between 1973 and 1991 and indexed in MEDLINE under the headings diabetic nephropathies and angiotensin-converting enzyme inhibitors.

MAIN OUTCOME MEASURES

The primary outcome indicators of interest were the effects of the ACE inhibitors captopril, enalapril, and lisinopril on BP control and urinary albumin excretion rate.

CONCLUSIONS

ACE inhibitors delay the onset and slow the progression of DN in people with diabetes independent of BP effects. They also slow the progression of DN in people with diabetes who have poorly controlled hyperglycemia. The proper dose and time at which to initiate ACE inhibitor therapy to prevent the appearance of DN is not known. It is also not known how long the beneficial effects of ACE-inhibitor therapy persists as only two studies have followed patients for more than one year. Finally, large, long-term, controlled clinical trials are needed before ACE inhibitors can be considered for prophylactic use to prevent the onset and/or progression of DN.