Pharmaceutically active compounds (PhACs) in surface water: Occurrence, trends and risk assessment in the Tagus River Basin (Spain).

In this study, the presence of 23 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, anti-inflammatories, psychiatric and cardiovascular drugs, antifungals and metabolites was investigated in surface waters. A total of 89 samples were collected during 3 years (2020, 2021 and 2022) from a European representative river basin (Tagus, Spain). To elucidate PhAC potential sources, sampling points located in areas with low, median and high anthropogenic influence were selected. The analytical method based on solid phase extraction (SPE) followed by UHPLC-MS/MS analysis was validated meeting SANTE/2020/12830 and SANTE/12682/2019 performance criteria. PhACs were quantified above limits of quantification (LOQs) in 96 % of water samples, being the antihypertensives valsartan (648 ng/L, 87 % quantification frequency) and irbesartan (390 ng/L, 75 %) and the antidepressant o-desmethylvenlafaxine (495 ng/L, 76 %) the predominant pollutants. The rest of the target PhACs showed median concentrations between 4 and 172 ng/L with quantification frequencies ranging from 35 to 75 %. ∑PhAC concentrations did not show temporal or seasonal trends. However, valsartan and naproxen presented lower levels in drier (spring and summer) compared to the wetter. Source identification revealed a clear anthropogenic origin since concentrations obtained in highly populated areas were statistically higher (p < 0.01) than those quantified in sparsely populated ones. This finding was also confirmed by calculating PhACs mass flow rates, which ranged between 1.4 and 235 kg/y. Finally, data generated were used to estimate the potential risk to the aquatic ecosystem for three trophic levels (phototrophic, invertebrate and vertebrate organisms). Risk quotient ratios (RQs) were calculated for all PhACs at the median (P50) and worst-case (max) scenarios. Up to 7 PhACs (acetaminophen, carbamazepine, gemfibrozil, ibuprofen, irbesartan, ketoprofen and venlafaxine) showed high risk for the highest trophic level (fish) in >45 % of investigated locations.

Cost-effectiveness of ultra-low-dose quadruple combination therapy for high blood pressure.

OBJECTIVE: To determine the cost-effectiveness and cost-utility of a quadpill containing irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg and bisoprolol 2.5 mg in comparison with irbesartan 150 mg for people with hypertension who are either untreated or receiving monotherapy. METHODS: We conducted a within-trial and modelled economic evaluation of the Quadruple UltrA-low-dose tReaTment for hypErTension trial. The analysis was preplanned, and medications and health service use captured during the trial. The main outcomes were incremental cost-effectiveness ratios (ICERs) for cost per mm Hg systolic blood pressure (BP) reduction at 3 months, and modelled cost per quality-adjusted life year (QALY) over a lifetime. RESULTS: The within-trial analysis showed no clear difference in cost per mm Hg BP lowering between randomised treatments at 3 months ($A10 (95% uncertainty interval (UI) $A -18 to $A37) per mm Hg per person) for quadpill versus monotherapy. The modelled cost-utility over a lifetime projected a mean incremental cost of $A265 (95% UI $A166 to $A357) and a mean 0.02 QALYs gained (95% UI 0.01 to 0.03) per person with quadpill therapy compared with monotherapy. Quadpill therapy was cost-effective in the base case (ICER of $A14 006 per QALY), and the result was sensitive to the quadpill cost in one-way sensitivity analysis. CONCLUSIONS: Quadpill in comparison with monotherapy is comparably cost-effective for short-term BP lowering. In the long-term, quadpill therapy is likely to be cost-effective. TRIAL REGISTRATION NUMBER: ANZCTRN12616001144404.

Prioritization based on risk assessment to study the bioconcentration and biotransformation of pharmaceuticals in glass eels (Anguilla anguilla) from the Adour estuary (Basque Country, France).

The presence of contaminants of emerging concern in the aquatic environment directly impacts water-living organisms and can alter their living functions. These compounds are often metabolized and excreted, but they can also be accumulated and spread through the food chain. The metabolized contaminants can also lead to the formation of new compounds with unknown toxicity and bioaccumulation potential. In this work, we have studied the occurrence, bioconcentration, and biotransformation of CECs in glass eels (Anguilla anguilla) using UHPLC-HRMS. To select the target CECs, we first carried out an environmental risk assessment of the WWTP effluent that releases directly into the Adour estuary (Bayonne, Basque Country, France). The risk quotients of every detected contaminant were calculated and three ecotoxicologically relevant contaminants were chosen to perform the exposure experiment: propranolol, diazepam, and irbesartan. An experiment of 14 days consisting of 7 days of exposure and 7 days of depuration was carried out to measure the bioconcentration of the chosen compounds. The quantitative results of the concentrations in glass eel showed that diazepam and irbesartan reached BCF ≈10 on day 7, but both compounds were eliminated after 7 days of depuration. On the other hand, propranolol's concentration remains constant all along with the experiment, and its presence can be detected even in the non-exposed control group, which might suggest environmental contamination. Two additional suspect screening strategies were used to identify metabolization products of the target compounds and other xenobiotics already present in wild glass eels. Only one metabolite was identified, nordiazepam, a well-known diazepam metabolite, probably due to the low metabolic rate of glass eels at this stage. The xenobiotic screening confirmed the presence of more xenobiotics in wild glass eels, prominent among them, the pharmaceuticals exemestane, primidone, iloprost, and norethandrolone.

Assessment of suitable antihypertensive therapies: Combination with high-dose amlodipine/irbesartan vs triple combination with amlodipine/irbesartan/indapamide (ASAHI-AI study).

Angiotensin receptor blockers (ARBs) plus calcium channel blockers (CCBs) are a widely used combination therapy for hypertensive patients. In order to determine which combination was better as the next-step therapy for standard-dose combination of ARBs and CCBs, a combination with high-dose CCBs or a triple combination with diuretics, the authors conducted a prospective, randomized, open-label trial to determine which of the following combination is better as the next-step treatment: a combination with high-dose CCBs or a triple combination with diuretics. Hypertensive outpatients who did not achieve their target blood pressure (BP) with usual dosages of ARBs and amlodipine 5 mg were randomly assigned to treatment with irbesartan 100 mg/amlodipine 10 mg (Group 1: n = 48) or indapamide 1 mg in addition to ARBs plus amlodipine 5 mg (Group 2: n = 46). The primary end point was changes in the systolic BP (SBP) and diastolic BP (DBP) after the 12-week treatment period, while secondary end points were changes in BP after the 24-week treatment period and laboratory values. At 12 weeks, the SBP/DBP significantly decreased from 152.1/83.4 mm Hg to 131.5/76.1 mm Hg in Group 1 and 153.9/82.1 mm Hg to 132.7/75.9 mm Hg in Group 2. Although both groups produced a similar efficacy in reducing the SBP/DBP (-19.2/-9.2 mm Hg in Group 1 and -21.6/-8.8 mm Hg in Group 2; SBP P = .378, DBP P = .825), high-dose CCBs combined with ARBs controlled hypertension without elevation of serum uric acid. These results will provide new evidence for selecting optimal combination therapies for uncontrolled hypertensive patients.

The cost-effectiveness of irbesartan for hypertension.

High blood pressure is a very common problem in the adult and elderly population, both in developed and developing countries. A relatively large number of drug classes are available to treat this condition and prevent its complications, which are not only more frequent in the aforementioned patients but also those affected by metabolic syndrome and/or Type 2 diabetes. Irbesartan is an angiotensin-receptor blocker class drug with good antihypertensive efficacy and specific pharmacological characteristics, whose efficacy has been more deeply evaluated in metabolically complex hypertensive patients. In this review, the authors will analyze its effectiveness in preventing or delaying organ damage in hypertensive patients, with a closer look at the economic implications of treating hypertension with irbesartan in the context of available antihypertensive drugs.

Assessment of effect of irbesartan and nebivolol on the left atrium volume and deformation in the patients with mild-moderate hypertension.

BACKGROUND: We aimed to assess the effects of irbesartan and nebivolol on the left atrium (LA) volume and deformation in the patients with mild-moderate hypertension. PATIENTS AND METHODS: The study comprised of 160 patients (mean age: 55.6±9.6 years), who had Stage 1 or 2 hypertension according to the European Society of Cardiology (ESC) and have not been receiving antihypertensive therapy. The patients were assigned to treatment groups; irbesartan (n=80) and nebivolol (n=80). The patients were clinically and echocardiographically reevaluated on the 6th and 12th months after the onset of treatment. RESULTS: There was no difference between the two treatment groups in terms of baseline demographic, clinical and echocardiographic characteristics. Moreover, no difference was observed between the treatment groups on the 6th and 12th months. Intragroup analyses revealed that systolic blood pressure (SBP) and diastolic blood pressure (DBP) significantly decreased in time and diastolic function parameters were improved. However, whilst significant increase was observed in conduit volume, decrease was observed in other volumes of the LA in the irbesartan and nebivolol groups. This significant change was observed on the 6th month in both treatment groups. LA global peak systolic strain (LAGLSs), LA global peak systolic strain rate (LAGLSRs), LA global peak strain rate during early ventricular diastole (LAGLSRe) and LA global peak strain rate (LAGLSRa) during late ventricular diastole (LAGLSRa) values began to be significantly increased after 6 months of treatment in both treatment groups. CONCLUSIONS: We found that nebivolol, which is a new generation beta blocker, is effective as irbesartan with proven efficacy in improving LA volume and LA myocardial performance in patients with mild-moderate hypertension. Moreover, we determined that strain and strain rate, which are the new echocardiographic parameters, are effective as LA volumes in assessing LA functions.

Comprehensive overview: efficacy, tolerability, and cost-effectiveness of irbesartan.

BACKGROUND: Hypertension represents a major health problem, affecting more than one billion adults worldwide. Irbesartan, an angiotensin II receptor blocker, is considered to be a highly effective treatment in the management of hypertension. The purpose of this review is to evaluate the efficacy, safety and tolerability profile, and cost-effectiveness of treatment with irbesartan in hypertension. METHODS: A review of the literature was conducted using the electronic PubMed and Cochrane Library databases and the Health Economic Evaluations Database of search terms relating to irbesartan efficacy, tolerability, and cost-effectiveness, and the results were utilized. RESULTS: Findings from the present analysis show that irbesartan either as monotherapy or in combination with other antihypertensive agents can achieve significant reductions in blood pressure, both systolic and diastolic, compared with alternative treatment options. Irbesartan was also found to have a renoprotective effect independent of its blood pressure-lowering in patients with type 2 diabetes and nephropathy. Furthermore, irbesartan demonstrated an excellent safety and tolerability profile, with either lower or equal adverse events compared with placebo and other alternative treatments. In terms of economic analyses, compared with other antihypertensive therapy alternatives, irbesartan was found to be a preferred option, that is less costly and more effective. CONCLUSION: The evidence indicates that treating patients with hypertension alone or with type 2 diabetes and nephropathy using irbesartan can control hypertension, prolong life, and reduce costs in relation to existing alternatives.

Sex differences in clinical characteristics and outcomes in elderly patients with heart failure and preserved ejection fraction: the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial.

BACKGROUND: There are few sex-specific outcome data in heart failure with preserved ejection fraction. METHODS AND RESULTS: We assessed sex differences in baseline characteristics and outcomes among 4128 patients with heart failure with preserved ejection fraction in the Irbesartan in Heart Failure with Preserved Ejection Fraction (I-PRESERVE) trial. Women (n=2491) with heart failure with preserved ejection fraction were ≈1 year older (72±7 years versus 71±7 years) and more likely to be obese (46% versus 35%) and have chronic kidney disease (34% versus 26%) and hypertension (91% versus 85%) than men but less likely to have an ischemic cause (19% versus 34%), atrial fibrillation (27% versus 33%), or chronic obstructive pulmonary disease (8% versus 13%) (all P<0.001). During a mean of 49.5 months, there were 881 deaths (447 in women, 434 in men; risk ratio, 0.64; 95% CI, 0.56-0.74) and 5776 hospitalizations (3239 in women, 2537 in men; risk ratio, 0.80; 95% CI, 0.76-0.84). Women had lower risk of all-cause events (deaths and hospitalizations), even after adjusting for baseline characteristics (adjusted hazards ratio, 0.81; 95% CI, 0.73-0.89). However, the sex-related difference in risk of all-cause events was modified in the presence or absence of atrial fibrillation, renal dysfunction, stable angina pectoris, or advanced New York Heart Association class symptoms. CONCLUSIONS: In patients with typical heart failure with preserved ejection fraction, there were prominent sex differences in baseline characteristics and outcomes. Women had better overall prognosis, although the presence of 4 common baseline characteristics seemed to moderate this finding.

I-ADD study: assessment of efficacy and safety profile of irbesartan/amlodipine fixed-dose combination therapy compared with irbesartan monotherapy in hypertensive patients uncontrolled with irbesartan 150 mg monotherapy: a multicenter, phase III, prospective, randomized, open-label with blinded-end point evaluation study.

BACKGROUND: Hypertension guidelines recommend the use of 2 agents with synergistic action when >1 agent is needed to achieve blood pressure goals. Newer antihypertensive treatment combinations include fixed-dose combinations of an angiotensin receptor blocker and a calcium channel blocker. OBJECTIVE: The I-ADD study aimed to demonstrate whether the antihypertensive efficacy of fixed-dose combination irbesartan 300 mg/amlodipine 5 mg (I300/A5) was superior to that of irbesartan (I300) monotherapy in lowering home systolic blood pressure after 10 weeks' treatment. METHODS: The I-ADD study was a 10-week, multicenter, Phase III, prospective, randomized, parallel-group, open-label with blinded-end point study. The main inclusion criterion was essential uncontrolled hypertension (systolic blood pressure ≥145 mm Hg at office after at least 4 weeks of irbesartan 150 mg [I150] monotherapy administered once daily). Patients continued to receive I150 for 7 to 10 days and were randomized to either monotherapy with I150 for 5 weeks then I300 for the next 5 weeks, or to a fixed-dose combination therapy (I150/A5, then I300/A5). Safety profile was assessed by recording adverse events reported by patients or observed by the investigator. RESULTS: Following enrollment, 325 patients were randomized to treatment, and 320 (mean [SD] age, 56.7 [11.4] years; 41% male) were included in the intention-to-treat analysis: 155 patients treated with I150/A5 then I300/A5, and 165 patients treated with I150 then I300. At randomization, mean home systolic blood pressure was similar in both groups: 152.7 (11.8) mm Hg in the I150/A5 group and 150.4 (10.1) mm Hg in the I150 group. At week 10, the adjusted mean difference in home systolic blood pressure between groups was -8.8 (1.1) mm Hg (P < 0.001). The percentage of controlled patients (mean home blood pressure <135 and 85 mm Hg) was nearly 2-fold higher in the I300/A5 group versus the I300 group (P < 0.001). Treatment-emergent adverse events were experienced by 10.5% of I300/A5-treated patients and 6.6% of I300-treated patients during the second 5-week period. Three serious adverse events were reported; 2 with monotherapy (1 with I150 and 1 with I300) and 1 with fixed-dose combination I300/A5. All patients affected by serious adverse events made a full recovery. CONCLUSIONS: These 10-week data from this patient population suggest a greater antihypertensive efficacy of the fixed-dose combination I300/A5 over I300 alone in lowering systolic blood pressure. Both treatments were well tolerated throughout the study. ClinicalTrials.gov identifier: NCT00957554.

I-COMBINE study: assessment of efficacy and safety profile of irbesartan/amlodipine fixed-dose combination therapy compared with amlodipine monotherapy in hypertensive patients uncontrolled with amlodipine 5 mg monotherapy: a multicenter, phase III, prospective, randomized, open-label with blinded-end point evaluation study.

BACKGROUND: Hypertension guidelines recommend the use of 2 agents with synergistic action when >1 agent is needed to achieve blood pressure goals. Newer antihypertensive treatment combinations include fixed-dose combinations of an angiotensin receptor blocker and a calcium channel blocker. OBJECTIVE: The I-COMBINE study aimed to determine whether the antihypertensive efficacy of the fixed-dose combination irbesartan 150 mg/amlodipine 5 mg (I150/A5) was superior to that of amlodipine 5 mg (A5) monotherapy in lowering home systolic blood pressure (HSBP) after 5 weeks' treatment. METHODS: The I-COMBINE study was a 10-week, multicenter, Phase III, prospective, randomized, parallel-group, open-label with blinded-endpoint study. The main inclusion criterion was essential uncontrolled hypertension (SBP ≥145 mm Hg at office, after at least 4 weeks of A5 monotherapy administered once daily). Patients continued to receive A5 for 7 to 10 days and were randomized to either monotherapy with A5 for 5 weeks then amlodipine 10 mg (A10) for the next 5 weeks or to a fixed-dose combination therapy (I150/A5 then I150/A10). Safety profile was assessed by recording adverse events reported by patients or observed by the investigator. RESULTS: Following enrollment, 290 patients were randomized to treatment, and 287 (mean [SD] age, 57.3 [11.2] years; 48% male) were included in the intention-to-treat analysis: 144 patients treated with I150/A5 then I150/A10, and 143 patients treated with A5 then A10. At randomization, mean HSBP was similar in both groups: 148.5 (10.3) mm Hg in the I150/A5 group and 149.2 (9.7) mm Hg in the A5 group. At week 5, the adjusted mean difference in HSBP between groups was -6.2 (1.0) mm Hg (P < 0.001). The proportion of controlled patients (mean home blood pressure <135 and 85 mm Hg) was significantly higher in the I150/A5 group than in the A5 group (P < 0.001). Treatment-emergent adverse events were experienced by 13.8% of I150/A5-treated patients and 11.9% of A5-treated patients during the first 5-week period, and by 15.8% of I150/A10-treated patients and 17.0% of A10-treated patients during the second 5-week period. Two serious adverse events were reported with the fixed-dose combination; both patients recovered. CONCLUSIONS: Data from this adult population with essential hypertension suggest greater efficacy with the fixed-dose combination I150/A5 over A5 monotherapy in lowering SBP after 5 weeks. Both treatment regimens were well tolerated throughout the study. ClinicalTrials.gov identifier: NCT00956644.

The role of irbesartan in the treatment of patients with hypertension: a comprehensive and practical review.

Irbesartan is an orally active angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB]) whose pharmacological profile differs significantly from those of many other compounds of the same class. In particular, according to its pharmacokinetic and pharmacodynamic profile, irbesartan has a high bioavailability, a long duration of action and a small potential for pharmacological interactions due to the nature of the enzymatic pathway involved in its metabolic process. Morbidity data with irbesartan have been mainly accumulated in patients with renal impairment where the drug has demonstrated the most remarkable evidence of efficacy among the ARBs class, regardless of the stage of the renal disease (from early to late) and the length of the observational period. The efficacy of irbesartan has also been demonstrated in patients with left ventricular hypertrophy and congestive heart failure. The drug is indicated for the treatment of hypertension and renal impairment in patients with type 2 diabetes mellitus (T2D) and hypertension, and its tolerability and safety profile have been extensively investigated and reported to be similar to placebo. From the pharmacoeconomic point of view, treating patients with T2D, hypertension and overt nephropathy using irbesartan was both a cost- and life-saving procedure compared with the use of amlodipine and standard antihypertensive treatment in an Italian setting. The role of irbesartan in the management of hypertension with or without T2D and renal impairment is clearly recognized by national and international guidelines and largely acknowledged by the medical community according to the efficacy of the drug in the prevention of cardiovascular risk in addition to and beyond kidney prevention.

Assessment of long-term effects of irbesartan on heart failure with preserved ejection fraction as measured by the minnesota living with heart failure questionnaire in the irbesartan in heart failure with preserved systolic function (I-PRESERVE) trial.

BACKGROUND: The Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used in a large, multinational, randomized, placebo-controlled trial to measure adverse effects of heart failure with preserved ejection fraction (HF-PEF) on patients' lives and the effects of irbesartan. METHODS AND RESULTS: Patients with symptomatic HF-PEF were randomly assigned to irbesartan (up to 300 mg daily) or placebo. The MLHFQ was administered at baseline (n=3605), month 6 (n=3137), month 14 (n=2904), and the end of study (median, 56 months, n=2205). Baseline MLHFQ scores of 43±21 indicated that HF-PEF had a substantial adverse effects. Estimated retest reliability was 0.80. Baseline MLHFQ scores were associated with other measures of the severity of heart failure including symptoms, signs of congestion, cardiac structure, and time to hospitalizations or deaths attributed to heart failure. Slight improvement in shortness of breath or fatigue was associated with significant improvement in MLHFQ scores (-5.9 and -5.0, P<0.0001). Compared with placebo, further improvement in MLHFQ scores was not observed with irbesartan after 6 months (mean adjusted difference, 0.4; 95% confidence interval, -0.8 to 1.7), 14 months (0.5; 95% confidence interval, -0.9 to 1.8), or the end of study (2.0; 95% confidence interval, -4.1 to 0.01). CONCLUSIONS: The MLHFQ scores are a reliable, valid, and sensitive measure of the adverse impact of HF-PEF on patients' lives. Irbesartan did not substantially improve MLHFQ scores during a long period of follow-up. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00095238.

Economic evaluation of irbesartan in combination with hydrochlorothiazide in the treatment of hypertension in Greece.

OBJECTIVES: Hypertension is a major risk factor for cardiovascular disease and a leading cause of morbidity and mortality. This study evaluates irbesartan in relation to commonly used alternative hypertension therapies losartan and valsartan given in combination with hydrochlorothiazide (HCTZ) in the general hypertensive population in Greece. METHODS: A Markov model with eight states of health was constructed: hypertension, myocardial infarction (MI), post-MI, angina, stroke, poststroke, heart failure, and death. The model has an annual cycle and estimates mean quality-adjusted survival and treatment cost, which reflect the hypertension treatment and managing cardiovascular events. Risk functions were used to conduct extrapolations. Data on treatment effectiveness, quality of life (QOL) and epidemiology were obtained from published clinical trials and studies. The database of the main Greek National Social Insurance Institute (IKA) was analyzed to estimate the cost of events. The analysis was done from a payer perspective. All outcomes were discounted, and prices correspond to 2008. RESULTS: The estimated patient cost per annum was stable angina euro 2,252, unstable angina euro 2,572, myocardial infarction euro 2,473, post-MI euro 1,677, stroke euro 12,233, poststroke euro 1,240, heart failure euro 2,655, coronary angiography euro 1,544, percutaneous transluminal coronary angioplasty euro 6,511, and coronary artery bypass graft surgery euro 11,514. For the baseline group (age 57 years, systolic blood pressure 147 mmHg, cholesterol 6.00 mmol/L, body mass index 29) of men with mild to moderate hypertension, for irbesartan, the total treatment cost was euro 15,146, for losartan euro 15,696 and for valsartan euro 15,613; the quality-adjusted life years (QALYs) were irbesartan 12.67, losartan 12.63 and valsartan 12.64. For the baseline group of women with mild to moderate hypertension, the total treatment cost was euro 12,945 for irbesartan, euro 13,424 for losartan and euro 13,379 for valsartan; QALYs were 14.29 for irbesartan, 14.27 for losartan and 14.27 for valsartan. For men with severe hypertension, for irbesartan and losartan, the total treatment cost was euro 18,679 and euro 21,488 and QALYs 12.47 and 12.37, respectively. For women, the total treatment cost was euro 16,202 and euro 19,099 and QALYs 14.16 and 14.09, respectively. Similar results were obtained in relation to other treatment groups in various sensitivity analysis scenarios. CONCLUSIONS: Based on efficacy data from clinical trials and lower attainment costs in various hypertensive patient populations, irbesartan in combination with HCTZ compares favorably with losartan and valsartan in combination with HCTZ in the Greek setting.

Urinary proteome analysis enables assessment of renoprotective treatment in type 2 diabetic patients with microalbuminuria.

BACKGROUND: Previously the angiotensin II receptor blocker Irbesartan has been demonstrated to reduce the risk for progression from microalbuminuria to macroalbuminuria in type 2 diabetic patients. The purpose of this study was to evaluate the effect of treatment with Irbesartan in type 2 diabetic patients with microalbuminuria on the urinary proteome. METHODS: High-resolution capillary-electrophoresis coupled to mass-spectrometry (CE-MS) was used to profile the low-molecular-weight proteome in urine of a subgroup of patients from a two year randomized irbesartan versus placebo therapy trial, which included hypertensive type 2 diabetic patients with microalbuminuria on ongoing antihypertensive medication (IRMA2-substudy). RESULTS: We demonstrate that the therapy with 300 mg Irbesartan daily over a period of two years results in significant changes of the urinary proteome. Both, a classifier developed previously that consists of urinary peptides indicative of chronic kidney disease, as well as several individual peptides changed significantly after treatment. These changes were not observed in the placebo-treated individuals. Most prominent are changes of urinary collagen fragments associated with progression of diabetic nephropathy, indicating normalization in urinary peptides. CONCLUSION: CE-MS analysis of urine enabled identification of peptides as potential surrogate markers for renoprotection in microalbuminuric type 2 diabetic patients, which show persistent improvement after longterm treatment with Irbesartan. The results suggest that a major benefit of treatment by Irbesartan may be improvement of collagen turnover, reduction of fibrosis. They further suggest that urinary proteome analysis could be utilized to assess potential benefit of therapeutic intervention, providing statistically significant results even on a small population.

Differences in pharmacology and their translation into differences in clinical efficacy--a comparison of the renin angiotensin blocking agents irbesartan and losartan.

IMPORTANCE OF THE FIELD: Guidelines recommend five antihypertensive drug classes, but which particular drug to choose is up to the treating physician. We aimed at an in-depth comparison of two frequently used angiotensin receptor blockers to provide evidence for this decision. AREAS COVERED IN THIS REVIEW: Pharmacology of irbesartan and losartan, their blood-pressure-lowering efficacy, their tolerability/safety, end-organ protective effects and economic evaluation. WHAT THE READER WILL GAIN: Both drugs differ in their oral bioavailability, potential for food interactions, degree of metabolism, dosing interval, time to peak, volume of distribution and terminal half-life. Irbesartan provides a greater and longer-lasting antihypertensive effect and was determined to be cost effective over losartan in Denmark and Sweden. Irbesartan was more effective in preventing deterioration of kidney function in patients with diabetic nephropathy, being cost effective from a German perspective. There is only one end point trial for either drug in patients with left ventricular hypertrophy, heart failure and atrial fibrillation, but no direct comparison. TAKE HOME MESSAGE: There is an incremental clinical benefit of irbesartan over losartan in the treatment of hypertension and diabetic nephropathy which can be substantiated by corresponding preclinical study evidence. This has translated into an economic benefit in a number of country-specific evaluations.

Cost-effectiveness of aliskiren in type 2 diabetes, hypertension, and albuminuria.

The Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) trial demonstrated that adding aliskiren, an oral direct renin inhibitor, at a dosage of 300 mg/d to the highest approved dosage of losartan and optimal antihypertensive therapy reduces albuminuria over 6 mo among patients with type 2 diabetes, hypertension, and albuminuria. The cost-effectiveness of this therapy, however, is unknown. Here, we used a Markov model to project progression to ESRD, life years, quality-adjusted life years, and lifetime costs for aliskiren plus losartan versus losartan. We used data from the AVOID study and the Irbesartan in Diabetic Nephropathy Trial (IDNT) to estimate probabilities of progression of renal disease. We estimated probabilities of mortality for ESRD and other comorbidities using data from the US Renal Data System, US Vital Statistics, and published studies. We based pharmacy costs on wholesale acquisition costs and based costs of ESRD and transplantation on data from the US Renal Data System. We found that adding aliskiren to losartan increased time free of ESRD, life expectancy, and quality-adjusted life expectancy by 0.1772, 0.1021, and 0.0967 yr, respectively. Total expected lifetime health care costs increased by $2952, reflecting the higher pharmacy costs of aliskiren and losartan ($7769), which were partially offset by savings in costs of ESRD ($4860). We estimated the cost-effectiveness of aliskiren to be $30,500 per quality-adjusted life year gained. In conclusion, adding aliskiren to losartan and optimal therapy in patients with type 2 diabetes, hypertension, and albuminuria may be cost-effective from a US health care system perspective.

HPLC determination of irbesartan in human plasma: its application to pharmacokinetic studies.

A simple and rapid HPLC method using fluorescence detection was developed for determination of irbesartan in human plasma. Sample preparation was accomplished through a simple deproteinization procedure with 0.4 mL of acetonitrile containing 800 ng/mL of losartan (internal standard), and to a 0.1 mL plasma sample. Chromatographic separation was performed on a Zorbax Xclipse XDB C18 column (150 x 4.6 mm, i.d., 5 microm) at 40 degrees C. An isocratic mobile phase, acetonitrile:0.1% formic acid (37:63, v/v), was run at a flow-rate of 1.0 mL/min, and the column eluent was monitored using a fluorescence detector set at excitation and emission wavelengths of 250 and 370 nm, respectively. The retention times of irbesartan and losartan were 4.4 and 5.9 min, respectively. This assay was linear over a concentration range of 10-5000 ng/mL with a lower limit of quantification of 10 ng/mL. The coefficient of variation for this assay precision was less than 8.48%, and the accuracy exceeded 94.4%. The mean relative recoveries of irbesartan and losartan were 98.4 and 99.1%, respectively. This method was successfully applied for pharmacokinetic study after oral administration of irbesartan (300 mg) to 23 Korean healthy male volunteers.

[Economics of nephroprotection in arterial hypertension and type 2 diabetes mellitus].

Based on results of large-scale controlled trials of irbesartan (I), valsartan (V) and amlodipine (A) (PRIME and MARVAL) we carried out the Markov s modeling of their pharmacoeconomic parameters in arterial hypertension (AH) combined with diabetes mellitus type 2 (DM 2) and microalbuminuria (MAU) projected for 8-years perspective. Cost and efficacy was evaluated taking into account years of life gained and outcomes of concomitant diseases and complications. Indexes of cost/efficacy (C/E) were calculated for each drug. Among investigated drugs I appeared to be the most economic at the account of retardation of development of terminal nephropathy and cardiovascular diseases. The use of I compared with V could save 565300 rub/100 patients/year. C/E of I was 26.5 and 37.4% lower that those of V and A, respectively. Costs of year of life saved was 12716, 16432, and 18325 for I, V, and A, respectively. Comparative pharmacoeconomic modeling of 8-year economic perspectives of I, V and A demonstrated financial benefits of I.

Cost-effectiveness of irbesartan/hydrochlorothiazide in patients with hypertension: an economic evaluation for Sweden.

Irbesartan, an angiotensin-II inhibitor, has been shown to be an effective antihypertensive agent in clinical trials. The purpose of this study was to assess the cost-effectiveness of irbesartan in combination with hydrochlorothiazide (HCTZ) in Swedish health-care setting by predicting clinical events and life years based upon observed reductions in blood pressure in clinical trials. The cost-effectiveness of antihypertensive treatment with irbesartan compared with placebo and to other selected angiotensin-II inhibitors (losartan, valsartan, candesartan) in combination with HCTZ was estimated using a Markov model. The incidence of cardiovascular disease was obtained from the Swedish inpatient registry, whereas the risk reductions associated with antihypertensive therapy were taken from the medical literature. Costs for antihypertensive therapy and for treatment of cardiovascular events were included, and the health effects were measured in terms of quality-adjusted life years (QALYs). The study was conducted from a health-care payer perspective. For a 55-year-old male, irbesartan 150 mg/HCTZ 12.5 mg was a dominant strategy (better health effects at lower costs) when compared with losartan 50 mg/HCTZ 12.5 mg and valsartan 80 mg/HCTZ 12.5 mg, and the cost-effectiveness ratio compared with placebo was 3500 euros per QALY gained. In moderate-to-severe hypertension, irbesartan was cost-effective compared with losartan, whereas the results compared with candesartan were mixed. High-dose combination therapy of irbesartan was also found to be cost-effective compared with low-dose combination therapy. The results from the model indicate that irbesartan provides a cost-effective antihypertensive treatment strategy compared with both placebo, and to valsartan and losartan.

Switch strategies in the management of hypertension: a cost minimisation analysis of angiotensin receptor blocker based regimen.

BACKGROUND AND OBJECTIVE: Budgetary pressures within health care systems have led many health care providers to consider the switching of patients on long term anti hypertensive medication to agents with the lowest acquisition price. The long term success of this strategy hinges on price differentials remaining stable, an assumption that may not be valid in drug classes where patent expiry times vary. The treatment of hypertension using angiotensin receptor blockers (ARBs) represents just such a case. The present study, therefore, modelled the 5-year cost consequences of treatment based on losartan, candesartan, valsartan and irbesartan, based on expected patent expiry dates. METHODS: A Markov model was constructed, applying dose-specific blood-pressure lowering and costs to a cohort of uncontrolled mild-moderate hypertensive patients and assessing the anticipated cost of treatment over a 5 year period. A probabilistic approach was adopted to account for between-patient and between-treatment differences. RESULTS: For both undiscounted and discounted models, a losartan-based regimen represents the least costly option of the four agents tested. Median (IQR) discounted expenditure per patient for each agent was: losartan: pound 506 ( pound 441- pound 650), candesartan: pound 610 ( pound 542- pound 766), valsartan: pound 809 ( pound 796- pound 1078), irbesartan pound 696 ( pound 694- pound 934). CONCLUSION: Switching hypertensive patients taking ARBs to the agent with the lowest current acquisition cost may yield only transient budgetary savings. Once patent expiry is taken into account, this model suggests that maintaining or switching patients to losartan would yield considerably greater savings over 5 years.