Nitrendipine and amlodipine mimic the acute effects of enalapril on renal haemodynamics and reduce glomerular hyperfiltration in patients with chronic kidney disease

Amlodipine decreases mitral regurgitation volume in dogs over 7 days: A study of 24 dogs with myxomatous mitral valve degeneration

Background

Amlodipine, a dihydropyridine calcium-channel blocker, is currently being investigated as a treatment for myxomatous mitral valvular degeneration (MMVD). However, the effects of amlodipine on moderate or severe spontaneous MMVD, based on changes in echocardiographic indices, remain unclear.

Animals

Client-owned small-breed dogs (n = 24) with naturally occurring MMVD of the American College of Veterinary Internal Medicine (ACVIM) stage B2 or higher.

Methods

Basic dog information including previous medication treatments were recorded. All subjects received amlodipine 0.1 mg/kg, administered per os, twice daily for 7 days, in addition to their existing medication. We measured systolic blood pressure, obtained x-ray, echocardiography, blood test data before and after 1 week of amlodipine administration.

Results

Left ventricular end-diastolic internal diameter, left atrial diameter and E wave reduced statistically after 1 week of amlodipine treatment (all p < 0.001). No adverse effects were reported.

Conclusions

These findings suggest that low-dose amlodipine should be considered as treatment for dogs with ACVIM stage B2‒C MMVD.

Metabolic and Cardiovascular Effects of Switching Thiazides to Amlodipine in Hypertensive Patients With and Without Type 2 Diabetes (the Diuretics and Diabetes Control Study)

Background: Different studies have indicated that thiazide diuretics can increase the risk of developing type 2 diabetes (T2D). Therefore, in this study, we investigated whether switching from hydrochlorothiazide (HCTZ) to amlodipine resulted in ameliorating different cardiovascular and metabolic measures in hypertensive patients with or without T2D. Methods: This study [Diuretics and Diabetes Control (DiaDiC)] was a 6-week, single-blind, single-center randomized controlled trial. The first 20 normal glucose-tolerant, 20 prediabetic, and 20 T2D consecutive patients were randomized to continue the previous antihypertensive treatment with HCTZ (12.5-25 mg/day) or to switch from HCTZ to amlodipine (2.5-10 mg/day). The primary endpoints were the absolute change in 7-day continuous subcutaneous glucose monitoring (CSGM) glycemia, serum uric acid concentrations, and endothelial function [measured as flow-mediated dilation (FMD)]. Other secondary endpoints were investigated, including changes in glycated hemoglobin (HbA₁c), glycemic variability from 7-day CSGM, and the estimated glomerular filtration rate (eGFR). Results: Amlodipine treatment was associated with a significant reduction in HbA₁c (P = 0.03) for both 7-day CSGM glycemia (P = 0.01) and glycemic variability (coefficient of variability %: HCTZ +3%, amlodipine -2.8%), and a reduction in uric acid concentrations (P < 0.001), especially in participants with T2D or prediabetes. Following amlodipine treatment, a significant increase in both eGFR (P = 0.01) and FMD (P = 0.02) was also observed. Conclusions: This study demonstrates that the replacement of HCTZ with amlodipine has several metabolic and cardiovascular beneficial effects. However, further intervention studies are necessary to confirm the clinical effects of thiazides, especially in diabetic people and in those at risk of diabetes.

Comparative Effect of Calcium Channel Blockers on Glomerular Function in Hypertensive Patients with Diabetes Mellitus

BACKGROUND

We conducted a retrospective cohort study to evaluate and compare the longitudinal effect of monotherapy with L-, L/T-, L/N-, and L/N/T-type calcium channel blockers (CCBs) on estimated glomerular filtration rate (eGFR), and to investigate the association of treatment duration with eGFR in diabetic patients with hypertension.

METHODS

Using a clinical database, we identified new users of five CCBs, i.e. amlodipine (L-type, n = 693), nifedipine (L-type, n = 189), azelnidipine (L/T-type, n = 91), benidipine (L/N/T-type, n = 183), and cilnidipine (L/N-type, n = 61). We used a multivariable regression model to evaluate and compare the effects of these drugs on eGFR and serum creatinine, up to 12 months after initiation of study drug administration.

RESULTS

There was no significant association between treatment duration and both eGFR and serum creatinine level with all CCB types. In addition, there was no significant difference in mean change in eGFR among the five CCBs, with any treatment duration.

CONCLUSIONS

Our findings suggest that monotherapy with an L-, L/T-, L/N/T-, or L/N-type CCB may have little influence on renal function parameters and may be safely used in hypertensive patients with diabetes.

Renal function monitoring in heart failure - what is the optimal frequency? A narrative review

The second most common cause of hospitalization due to adverse drug reactions in the UK is renal dysfunction due to diuretics, particularly in patients with heart failure, where diuretic therapy is a mainstay of treatment regimens. Therefore, the optimal frequency for monitoring renal function in these patients is an important consideration for preventing renal failure and hospitalization. This review looks at the current evidence for optimal monitoring practices of renal function in patients with heart failure according to national and international guidelines on the management of heart failure (AHA/NICE/ESC/SIGN). Current guidance of renal function monitoring is in large part based on expert opinion, with a lack of clinical studies that have specifically evaluated the optimal frequency of renal function monitoring in patients with heart failure. Furthermore, there is variability between guidelines, and recommendations are typically nonspecific. Safer prescribing of diuretics in combination with other antiheart failure treatments requires better evidence for frequency of renal function monitoring. We suggest developing more personalized monitoring rather than from the current medication-based guidance. Such flexible clinical guidelines could be implemented using intelligent clinical decision support systems. Personalized renal function monitoring would be more effective in preventing renal decline, rather than reacting to it.

Amlodipine Reduces Inflammation despite Promoting Albuminuria in the Streptozotocin-Induced Diabetic Rat

Amlodipine reduces blood pressure; however, its effect in the diabetic kidney irrespective of its blood pressure-lowering effects is unclear. This study examined the effects of amlodipine (0, 5, 10 and 20 mg/kg; D_A0, D_A5, D_A10 and D_A20, respectively) for 12 weeks on renal functional and structural changes in the streptozotocin-induced diabetic rat, a nonhypertensive model of diabetes-associated hyperfiltration. Compared with nondiabetic rats, diabetes (D) was associated with increased urine albumin excretion (UAE, 12.6 ± 3.40 vs. 3.73 ± 1.14 mg/day), glomerular filtration rate (2.17 ± 0.09 vs. 1.64 ± 0.12 ml/min/g kidney weight), glomerulosclerosis (0.21 ± 0.03 vs. 0.05 ± 0.01 AU) and infiltration of inflammatory cells (18.5 ± 2.78 vs. 6.92 ± 0.70 cells/cm²), but did not affect mean arterial pressure (MAP, 110 ± 4.70 vs. 109 ± 5.33 mm Hg). While D_A20 abolished glomerular hyperfiltration (1.49 ± 0.05 ml/min/g kidney weight) and inflammatory cell abundance (6.0 ± 0.79 cells/cm²), it exacerbated UAE (43.5 ± 8.49 mg/day) and increased MAP (132 ± 3.76 mm Hg), but had no effect on renal pathology. These data suggest that amlodipine reduces renal inflammation and abolished glomerular hyperfiltration, but increases blood pressure and exacerbates albuminuria in the rat model of normotensive diabetic kidney disease. We conclude that amlodipine may have limited renoprotective effects in the face of hyperfiltration and absence of elevated blood pressure.

Microemulsions as carriers for drugs and nutraceuticals

Microemulsions are potentially excellent carriers for bioactive molecules. They offer the advantage of spontaneous formation, ease of manufacture, thermodynamic stability, and improved solubilization of bioactive materials. This review explores some of the new trends in microemulsion research through analysis of some representative studies. The solubilization of different classic drugs, peptides, and nutraceuticals in various oral microemulsion compositions and microstructures was reviewed. It was found that even W/O microemulsions, which are expected to break upon dilution in the digestive tract, increase the permeability and bioavailability of drugs. Thus, it seems that component selection (the use of molecules that can act as permeability enhancers) is of great importance. Structures such as self-microemulsifying drug delivery systems (SMEDDS), W/O, bicontinuous, and O/W microemulsions, were closely examined, and their potential to serve as drug carriers was evaluated. It seems that for microemulsion systems to be used as vehicles for bioactive materials, the formulations should be based on SMEEDS, which form O/W upon dilution to a specific water content. U-type microemulsions are actually an improved SMEDDS formulation, capable of being diluted with any given water concentration. Much research is being conducted on microemulsion microstructure since there is an obvious direct connection between the microstructure, solubilization capacity, and bioavailability of the active molecules.

Amlodipine preserves the glomerular number in spontaneously hypertensive rats

The calcium channel blockers have individual pharmacological and therapeutic properties that may vary, but as a group, they are effective antihypertensive agents in patients with renal disease. Their effects on the kidney may extend beyond BP reduction alone. Fifteen one-year-old male spontaneously hypertensive rats (SHR) were separated in three groups: Initial control group (IC), Final control group (FC, SHR received standard rat chow and fresh water ad libitum during 15 weeks), Amlodipine group (Aml, SHR) received 0.2 mg/kg/day of amlodipine in addition to food and water during 15 weeks. The glomerular number was estimated using the disector method. In the Control group, the BP level increased almost 20 per cent in the first six weeks (from 186 +/- 11 to 223 +/- 16 mmHg, p<0.01) and then BP level increased almost 15 percent until week 15 (from 223 +/- 16 to 258 +/- 20 mmHg, p<0.01). In the same period, the Aml group showed a progressively low BP, reaching a level almost 50 per cent lower in the week 15 than in the week 1 (from 190 +/- 15 to 101+/-8 mmHg, p<0.01). Amlodipine treatment significantly decreased the serum creatinine, more than 12 per cent lower than the FC group (from 70.4 +/- 6.2 to 61.4 +/- 5.2 micromol/L, p<0.05). However, proteinuria was not different when groups were compared. The FC group reached a glomerular number almost 20 percent smaller than the IC and Aml groups (from 35 x 10(3) +/- 7 x 10(3) in IC group, 34 x 10(3) +/- 4 x 10(3) in Aml group to 27 x 10(3) +/- 3 x 10(3) in FC group, p<0.05). A possible protective effect of amlodipine against the loss of glomeruli in SHR is a major additional action of amlodipine in the treatment of hypertension mainly when the renal lesion already exists.