Zofenopril plus hydrochlorothiazide: Combination therapy for the treatment of mild to moderate hypertension

Validation of population pharmacokinetic models: a comparison of internal and external validation approaches for hydrochlorothiazide

1. Model evaluation is an important issue in population analyses. Our aim was to perform and illustrate metrics and techniques for internal and external evaluation with an application to population pharmacokinetics of hydrochlorothiazide (HCTZ).2. A nonlinear mixed effects model was used to study the pharmacokinetics of HCTZ. In addition, different types of internal assessment tools and external metrics were used for model evaluation. External evaluation was performed using an alternative dataset that included data from an independent group of subjects. For comparison, a previously published population pharmacokinetic model for HCTZ was applied to the same data.3. A two-compartment model with first-order oral absorption using a constant time delay between administration and absorption and first-order elimination best described HCTZ pharmacokinetics. Age had a statistically significant effect on HCTZ clearance. The final model performed adequately in the internal and external assessment tests. The final model showed better predictive performance than the other previously published HCTZ model.4. Finally, a robust population pharmacokinetic model for HCTZ in adults was constructed and validated internally and externally. Incorporating analytical assessment of nonlinear pharmacokinetics into the modelling may be a promising approach to improve the predictive power of the model.

Quantitative Estimation of Anti Hypertension Combination by Ratio Subtraction Spectrophotometry Method

BACKGROUND:

Irbesartan and hydrochlorothiazide are a group of anti-hypertensive drugs that are very effective and safe to use to reduce blood pressure and oedema. The combination has a small active ingredient content so that if the treatment didn’t meet the requirements for therapeutic doses, it not achieved to the maximum therapy.

AIM:

The research aims to the simultaneous determination of irbesartan and hydrochlorothiazide in tablets by Ratio subtraction spectrophotometry method.

METHODS:

The absorption spectra and sample measurement in the Ratio subtraction method performed on Irbesartan at a wavelength of 247.6 nm and 273.6 nm for the Hydrochlorothiazide (HCT) using 0.1 N NaOH as a solution. This method is validated with linearity, accuracy, and precision in intraday and interday, LOD and LOQ and applied in the determination of a mixture of irbesartan and hydrochlorothiazide in the dosage tablet.

RESULTS:

The validation test for IRB is 101.03 for accuracy, with a precision of 0.57; with precision testing at intraday 0.34 and interday 1.34, and LOD is 0.70 and LOQ is 2.12. Meanwhile, validation for HCT that the accuracy 100.34%; precision 0.89 and precision on intraday 1.20 and interday 1.18, and LOD 0.78 and LOQ 2.37 with IRB levels are 101.03 ± 0.63% and HCT is 100.59 ± 0.91%.

CONCLUSION:

The ultraviolet spectrophotometric method in subtraction ratio method was validated a method of linearity, accuracy, precision in intraday and interday, LOD, and LOQ and according to ICH guidelines and successfully applied for the determination simultaneous of irbesartan and hydrochlorothiazide in the tablet’s dosage form.

Efficacy of Zofenopril vs. Irbesartan in Combination with a Thiazide Diuretic in Hypertensive Patients with Multiple Risk Factors not Controlled by a Previous Monotherapy: A Review of the Double-Blind, Randomized "Z" Studies

Combinations between an angiotensin converting enzyme (ACE) inhibitor or an angiotensin II receptor blocker (ARB) and hydrochlorothiazide (HCTZ) are among the recommended treatments for hypertensive patients uncontrolled by monotherapy. Four randomized, double-blind, parallel group studies with a similar design, including 1469 hypertensive patients uncontrolled by a previous monotherapy and with ≥1 cardiovascular risk factor, compared the efficacy of a combination of a sulfhydryl ACE inhibitor (zofenopril at 30 or 60 mg) or an ARB (irbesartan at 150 or 300 mg) plus HCTZ 12.5 mg. The extent of blood pressure (BP)-lowering was assessed in the office and over 24 h. Pleiotropic features of the treatments were evaluated by studying their effect on systemic inflammation, organ damage, arterial stiffness, and metabolic biochemical parameters. Both treatments similarly reduced office and ambulatory BPs after 18-24 weeks. In the ZODIAC study a larger reduction in high sensitivity C reactive protein (hs-CRP) was observed under zofenopril (-0.52 vs. +0.97 mg/dL under irbesartan, p = 0.001), suggesting a potential protective effect against the development of atherosclerosis. In the ZENITH study the rate of carotid plaque regression was significantly larger under zofenopril (32% vs. 16%; p = 0.047). In the diabetic patients of the ZAMES study, no adverse effects of treatments on blood glucose and lipids as well as an improvement of renal function were observed. In patients with isolated systolic hypertension of the ZEUS study, a slight and similar improvement in renal function and small reductions in pulse wave velocity (PWV), augmentation index (AI), and central systolic BP were documented with both treatments. Thus, the fixed combination of zofenopril and HCTZ may have a relevant place in the treatment of high-risk or monotherapy-treated uncontrolled hypertensive patients requiring a more prompt, intensive, and sustained BP reduction, in line with the recommendations of current guidelines.

Blood Pressure Response to Zofenopril or Irbesartan Each Combined with Hydrochlorothiazide in High-Risk Hypertensives Uncontrolled by Monotherapy: A Randomized, Double-Blind, Controlled, Parallel Group, Noninferiority Trial

In this randomized, double-blind, controlled, parallel group study (ZENITH), 434 essential hypertensives with additional cardiovascular risk factors, uncontrolled by a previous monotherapy, were treated for 18 weeks with zofenopril 30 or 60 mg plus hydrochlorothiazide (HCTZ) 12.5 mg or irbesartan 150 or 300 mg plus HCTZ. Rate of office blood pressure (BP) response (zofenopril: 68% versus irbesartan: 70%; p = 0.778) and 24-hour BP response (zofenopril: 85% versus irbesartan: 84%; p = 0.781) was similar between the two treatment groups. Cardiac and renal damage was equally reduced by both treatments, whereas the rate of carotid plaque regression was significantly larger with zofenopril. In conclusion, uncontrolled monotherapy treated hypertensives effectively respond to a combination of zofenopril or irbesartan plus a thiazide diuretic, in terms of either BP response or target organ damage progression.

Antihypertensive effect of zofenopril plus hydrochlorothiazide versus zofenopril monotherapy in patients with essential hypertension according to their cardiovascular risk level: A post hoc analysis

BACKGROUND

International guidelines recommend the use of angiotensin-converting enzyme inhibitors, possibly in combination with other antihypertensive drugs, to treat hypertension with associated risk factors.

OBJECTIVE

The aim of this study was to compare the antihypertensive effect of the combination of zofenopril plus hydrochlorothiazide versus zofenopril monotherapy in patients with essential hypertension, according to their cardiovascular risk level.

METHODS

This was a post hoc analysis of a previously published efficacy and tolerability study. After a 4-week placebo washout, patients with mild to moderate essential hypertension (diastolic blood pressure [DBP] 95-115 mm Hg), aged 18 to 75 years, were randomized at a ratio of 2:1:1 to treatment with zofenopril 30 mg plus hydrochlorothiazide 12.5 mg or monotherapy with zofenopril 30 mg or hydrochlorothiazide 12.5 mg for 12 weeks in an international, multicenter, double-blind study. This period was followed by 24 weeks of open-label treatment. Systolic BP [SBP] and DBP were measured by mercury sphygmomanometry, and changes associated with treatment were calculated. Patients' cardiovascular risk was computed using the Heart Score algorithm. Patients were classified in quartiles according to distribution of cardiovascular risk level, and comparisons were limited to the zofenopril plus hydrochlorothiazide and zofenopril monotherapy treatment groups. The primary end point was change in office DBP.

RESULTS

Two hundred forty-six patients (139 men, 107 women; mean [SD] age, 54 [11] years) were included in the analysis. Mean baseline cardiovascular risk was similar in the zofenopril plus hydrochlorothiazide group and the zofenopril monotherapy group (7% vs 9%). DBP and SBP reductions with treatment were significantly greater (both, P < 0.01) with combination treatment than with monotherapy for each quartile of cardiovascular risk. Cardiovascular risk reduction at the end of the 12 weeks of double-blind treatment was greater in the zofenopril plus hydrochlorothiazide group than in the zofenopril monotherapy group (1.9% vs 0.2%; P < 0.01), particularly in the group of patients with the highest cardiovascular risk at baseline (5.2% vs 2.0%). At the end of the 24-week open-label treatment period, the mean reduction in cardiovascular risk was also significantly greater in the combination treatment group than in the monotherapy group (1.4% vs 0.5%; P < 0.01).

CONCLUSIONS

In these hypertensive patients, combination treatment with zofenopril plus hydrochlorothiazide was associated with a significantly greater decrease in BP compared with zofenopril monotherapy, regardless of the patient's cardiovascular risk. The difference between combination treatment and monotherapy was particularly evident for the group of patients at highest risk.

Zofenopril plus hydrochlorothiazide and irbesartan plus hydrochlorothiazide in previously treated and uncontrolled diabetic and non-diabetic essential hypertensive patients

INTRODUCTION

In most treated patients with hypertension, a two or more drug combination is required to achieve adequate blood pressure (BP) control. In our study we assessed whether the combination of zofenopril + hydrochlorothiazide (HCTZ) was at least as effective as irbesartan + HCTZ in essential hypertensives with at least one additional cardiovascular risk factor, uncontrolled by a previous monotherapy.

METHODS

After a 2-week placebo washout, 361 treated hypertensive patients [office sitting diastolic BP (DBP), ≥90 mmHg], aged 18-75 years, were randomized double blind to 18-week treatment with zofenopril 30 mg plus HCTZ 12.5 mg or irbesartan 150 mg plus HCTZ 12.5 mg once daily, in an international, multicenter study. After the first 6 and 12 weeks, zofenopril and irbesartan doses could be doubled in non-normalized subjects. The primary study end point was the office sitting DBP reduction after 18 weeks of treatment. Secondary end points included office systolic BP (SBP), ambulatory BP and high sensitivity C-reactive protein (hs-CRP).

RESULTS

The between-treatment difference for office DBP averaged to +1.0 (95% CI -0.4, +0.8) mmHg (P = 0.150), the upper limit of the 95% confidence interval being inferior to the protocol-defined non-inferiority limit (3 mmHg). In the subset of patients with valid ambulatory BP, no difference in 24-h average DBP [n = 181; 6.7 (8.7, 4.6) zofenopril + HCTZ vs. 6.3 (8.8, 3.7) mmHg irbesartan + HCTZ, P = 0.810] and SBP reductions [11.7 (15.4, 8.0) vs. 12.6 (17.2, 8.0) mmHg, P = 0.758] were observed between the two treatment groups. hs-CRP was reduced by zofenopril + HCTZ [-0.52 (-1.05, 0.01) mg/L], while it was increased by irbesartan plus HCTZ [0.97 (0.29, 1.65) mg/L, P = 0.001 between treatments].

CONCLUSION

In previously monotherapy-treated, uncontrolled patients with hypertension, zofenopril 30-60 mg + HCTZ 12.5 mg is as effective as irbesartan 150-300 mg plus HCTZ 12.5 mg, with the added value of a potential protective effect against vascular inflammation.

Zofenopril and incidence of cough: a review of published and unpublished data

OBJECTIVE

Cough is a typical side effect of angiotensin-converting enzyme (ACE) inhibitors, though its frequency quantitatively varies among the different compounds. Data on the incidence of cough with the lipophilic third-generation ACE inhibitor zofenopril are scanty and never systematically analyzed. The purpose of this paper is to give an overview on the epidemiology, pathophysiology, and treatment of ACE inhibitor-induced cough and to assess the incidence of cough induced by zofenopril treatment.

METHODS

Published and unpublished data from randomized and postmarketing zofenopril trials were merged together and analyzed.

RESULTS

Twenty-three studies including 5794 hypertensive patients and three studies including 1455 postmyocardial infarction patients exposed for a median follow-up time of 3 months to zofenopril at doses of 7.5-60 mg once-daily were analyzed. The incidence of zofenopril-induced cough was 2.6% (range 0%-4.2%): 2.4% in the hypertension trials (2.4% in the double-blind randomized studies and 2.4% in the open-label postmarketing studies) and 3.6% in the doubleblind randomized postmyocardial infarction trials. Zofenopril-induced cough was generally of a mild to moderate intensity, occurred significantly (P < 0.001) more frequently in the first 3-6 months of treatment (3.0% vs 0.2% 9-12 months), and always resolved or improved upon therapy discontinuation. Zofenopril doses of 30 mg and 60 mg resulted in significantly (P = 0.042) greater rate of cough (2.1% and 2.6%, respectively) than doses of 7.5 mg and 15 mg (0.4% and 0.7%, respectively). In direct comparison trials (enalapril and lisinopril), incidence of cough was not significantly different between zofenopril and other ACE inhibitors (2.4% vs 2.7%).

CONCLUSION

Evidence from a limited number of studies indicates a relatively low incidence of zofenopril-induced cough. Large head-to-head comparison studies versus different ACE inhibitors are needed to highlight possible differences between zofenopril and other ACE inhibitors in the incidence of cough.

Comparison of home and office blood pressure in hypertensive patients treated with zofenopril or losartan

In a parallel double-blind multicentre study, 375 hypertensive patients were enrolled and treated with either the angiotensin-converting enzyme inhibitor (ACEI) zofenopril 30 mg once daily (titration 60 mg od) or the angiotensin II type 1 receptor (AT1) antagonist losartan 50 mg od (titration 100 mg od). Patients with mild to moderate hypertension, defined as a diastolic blood pressure (DBP) between 95 and 110 mmHg in the sitting position without other signs of cardiovascular disease were enrolled and treated for 12 weeks. BP was assessed in the clinic, and self-measured by the patients at home during a working day and a holiday, as well as before and at the clinic follow-ups. Systolic (SBP) and DBP were significantly reduced in both treatment groups to a similar extent at the end of the 12-week study. However, the immediate or early reduction of DBP as well as DBP reduction over the first month was significantly greater with zofenopril (p= 0 .01 and p= 0 .003, respectively) compared with losartan treatment. After 3 months of treatment and dose up-titration, clinic BP reductions were similar in both groups. However, more subjects with losartan had used a higher dose step (42.1%) compared with zofenopril (33.1%). Home BP assessments demonstrated that systolic and diastolic pressures were substantially lower than the BP measurements made by sphygmomanometer in the clinic. In particular, assessments 2-3 days before the clinic visits during working days and holidays were characteristically lower, while the measurements during the clinic visits were largely similar to the conventional BP measurements by the doctor. The number and the severity of adverse events, related to the study medications, were largely benign and similar in both groups. The present study demonstrates that zofenopril in clinically recommended doses is at least therapeutically equivalent to losartan treatment, when assessed by conventional sphygmomanometry at the doctor's office or at home by self-measured BP assessments by the patients. Zofenopril however, induces a more rapid initial lowering of BP over the first month of therapy.

Antihypertensive efficacy of zofenopril compared with atenolol in patients with mild to moderate hypertension

Two first-line antihypertensive therapies for initiating treatment in hypertension were compared, the angiotensin-converting enzyme inhibitor (ACEI) zofenopril and the beta-blocker atenolol. The study was multi-centre and double-blind, and included 304 middle-aged to elderly patients with mild to moderate hypertension who were randomized to receive either zofenopril 30-60 mg once daily (od) or atenolol 50-100 mg od for 4 weeks with the possibility to an up-titration in non-responding patients. The higher dose level was then administered until 12 weeks after randomization. Blood pressures (BPs) were substantially reduced by either treatment, but after 4 weeks, the systolic and diastolic BP reductions were significantly greater (p < 0.05) with zofenopril (-15.6/-13.5 mmHg) compared with atenolol (-13.1/-11.8 mmHg). After 12 weeks and the possibility of dose up-titration, BP differences between treatments were no longer significant. However, control rates (sitting diastolic BP < 90 mmHg) for zofenopril remained significantly higher compared with atenolol. The number of subjects with adverse drug reactions possibly or probably related to the study medication was 14 (9.1%) in the zofenopril group and 30 (20.8%) in the atenolol group (p = 0.008). It is concluded that zofenopril as well as atenolol induces substantial reductions of diastolic BP in middle-aged to elderly patients with hypertension. However, the control rate when initiating antihypertensive therapy with zofenopril is higher than that for atenolol.

Maximising antihypertensive effects of angiotensin II receptor blockers with thiazide diuretic combination therapy: focus on irbesartan/hydrochlorothiazide

BACKGROUND

Evidence-based guidelines for the management of hypertension are now well established. Studies have shown that more than 60% of patients with hypertension will require two or more drugs to achieve current treatment targets.

DISCUSSION

Combination therapy is recommended as first-line treatment by the JNC-7 guidelines for patients with a blood pressure > 20 mmHg above the systolic goal or 10 mmHg above the diastolic goal, while the International Society of Hypertension in Blacks recommends combination therapy when BP exceeds targets by > 15/10 mmHg. Current European Society of Hypertension-European Society of Cardiology guidelines also recommend the use of low-dose combination therapy in the first-line setting. Furthermore, JNC-7 recommends that a thiazide-type diuretic should be part of initial first-line combination therapy. Thiazide/diuretic combinations are available for a variety of classes of antihypertensive, including ACE inhibitors, angiotensin receptor blockers (ARBs), beta blockers and centrally acting agents. This article focuses on clinical data investigating the combination of an ARB, irbesartan, with the diuretic, hydrochlorothiazide.

CONCLUSIONS

These data indicate that the ARB/HCTZ combination has greater potency and a similar side effect profile to ARB monotherapy and represents a highly effective approach for attaining goal BP levels using a therapeutic strategy that very effectively lowers BP, is well tolerated and minimises diuretic-induced metabolic effects.

Antihypertensive efficacy of zofenopril plus hydrochlorothiazide fixed combination for treatment in metabolic syndrome

This study was undertaken to compare the antihypertensive efficacy of zofenopril 30 mg + hydrochlorothiazide 12.5 mg fixed combination versus zofenopril alone in patients with essential hypertension with and without the metabolic syndrome, according to National Cholesterol Education Program-Adult Treatment Panel III criteria. After a 4-wk placebo washout period, 463 patients with mild to moderate essential hypertension (diastolic blood pressure [DBP] 95-115 mm Hg) aged 18 to 75 y were randomly assigned 2:1:1 to treatment with zofenopril+hydrochlorothiazide, zofenopril, or hydrochlorothiazide for 12 wk in an international, multicenter, double-blind, parallel-group study. DBP and systolic blood pressure changes with treatment were calculated. The first 12 wk of treatment were followed by a 24-wk open-label period during which only safety was assessed. Reported here is a subanalysis of the main study results, performed in patients with and without metabolic syndrome, limited to a zofenopril+hydrochlorothiazide versus zofenopril comparison. The antihypertensive effect of zofenopril+hydrochlorothiazide or zofenopril was similar in patients with (77%) and without metabolic syndrome. In patients with and without metabolic syndrome, however, DBP and systolic blood pressure reductions were significantly greater with zofenopril+hydrochlorothiazide (with metabolic syndrome: 14+/-8/21+/-14 mm Hg; without metabolic syndrome: 15+/-7/23+/-14 mm Hg) than with zofenopril alone (with metabolic syndrome: 10+/-9/11+/-15; without metabolic syndrome: 12+/-10/14+/-18 mm Hg). The safety of the 2 treatments was similar in patients with and without metabolic syndrome. The fixed combination of zofenopril+hydrochlorothiazide improved the efficacy of zofenopril alone. This effect was particularly evident in patients with metabolic syndrome, in whom blood pressure control is more difficult to achieve and who are at greater risk for cardiovascular events.

Defining the role of zofenopril in the management of hypertension and ischemic heart disorders

Zofenopril is a specific ACE inhibitor with antihypertensive, remarkable antioxidant, and cardioprotective properties, including the ability to improve endothelial function and protect against ischemia. These beneficial properties of zofenopril are believed to be due primarily to the presence of a sulfhydryl group and the highly lipophilic nature of the agent. As a potent, long-acting ACE inhibitor with tissue selectivity, it is a useful agent for the treatment of a number of cardiovascular diseases. ACE inhibitors block the renin-angiotensin-aldosterone system (RAAS) and are recommended in the management of hypertension with associated risk factors because of their renoprotective and cardioprotective effects. There is a robust body of comparative data supporting zofenopril as an effective and well tolerated ACE inhibitor for treating hypertension. Hypertensive patients frequently require combination therapy to adequately control BP. ACE inhibitors combined with a diuretic make a very effective combination, as a result of the synergistic mechanisms of these two drug classes that allow good efficacy and favorable tolerability at low doses. The combination of zofenopril and hydrochlorothiazide is effective and superior to monotherapy with either agent. Clinical studies have demonstrated that early administration of zofenopril in patients with acute myocardial infarction is effective and well tolerated for reducing the incidence of major cardiovascular events in at-risk patients, and it is believed that much of the benefit is a result of the primary cardioprotective effect of zofenopril.

Fixed combination of zofenopril plus hydrochlorothiazide in the management of hypertension: a review of available data

Angiotensin-converting enzyme (ACE) inhibitors effectively interfere with the renin-angiotensin system and exert various beneficial actions on vascular structure and function beyond their blood pressure-lowering effects. Zofenopril, a potent sulphydryl ACE inhibitor, is characterized by high lipophilicity, sustained cardiac ACE inhibition, and antioxidant and tissue protective activities. Its ancillary properties, such as antioxidant activity and cardiovascular (CV) protection, make this drug potentially suitable for the treatment and prevention of certain CV diseases. The Survival of Myocardial Infarction Long term Evaluation trials have demonstrated that the early administration of zofenopril to patients with acute myocardial infarction is associated with a significant reduction in the 6-week occurrence of major CV events in high-risk patients with anterior non-thrombolyzed myocardial infarction. The fixed combination of zofenopril-hydrochlorothiazide (HCTZ) 30/12.5 mg/day is approved for the management of mild-to-moderate hypertension in different European countries. In clinical trials comparing zofenopril-HCTZ with each agent administered as monotherapy, combination therapy was clearly more effective in normalizing blood pressure (BP). In addition, combination therapy provided sustained and consistent BP control over the entire 24 hour dosing interval. The efficacy and safety profile of zofenopril-HCTZ highlights that this combination is a potentially useful addition to currently available therapy for patients with BP inadequately controlled by monotherapy, as well as for patients who require more rapid and intensive BP control.