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.

[Fixed drug combinations in hypertension: a budget impact analysis for the Spanish Health System on the marketing of a fixed combination of olmesartan/amlodipine]. / Las combinaciones fijas en hipertensión: análisis de impacto presupuestario para el Sistema Nacional de Salud Español de la comercialización de la combinación fija de olmesartan/amlodipino.

OBJECTIVE: To carry out a budget impact analysis (BIA) of olmesartan/amlodipine (20/5, 40/5 and 40/10mg) marketed as a fixed combination (FC) in its approved indication for the National Health System (NHS). DESIG: We developed a decision tree model in order to estimate usual hypertension treatment algorithm in Spanish clinical practice. SETTINGS: The BIA has been developed from the perspective of the NHS for a period of 3 years (years 2010-2012). PARTICIPANTS: Spanish hypertensive population ≥ 35 years old. INTERVENTIONS: Introduction into the market of a fixed combination (FC) olmesartan/amlodipine in Spain. PRIMARY MEASURES: Expected costs to be assumed by the Spanish NHS (RRP-VAT) for hypertensive population able to be treated with the FC versus currently assumed costs by the NHS with free combination olmesartan and amlodipine. RESULTS: Estimated pharmaceutical costs in hypertensive population treated with olmesartan and amlodipine (2 pills) would be €25.2M (1(st) year), €26.4M (2011), €27.6M (2012), with a total 3-year period of €79.2M. According to patient tree model, the population able to be treated with FC would be 71,283 patients (2010), with a growth rate of 4.8% in the successive years, which supposes an annual cost of €21.2M (2010), €21.8M (2011) and €22.4M (2012), with a total 3-year period of €65.4M. The BIA shows savings of €13.8M in a total 3-year period. CONCLUSION: The BIA of FC olmesartan/amlodipine could generate net savings of €13.8M for the NHS in the period ranging from years 2010 to 2012.

Cost-effectiveness analysis: controlled-release nifedipine and valsartan combination therapy in patients with essential hypertension: the adalat CR and valsartan cost-effectiveness combination (ADVANCE-Combi) study.

As recommended by the guidelines such as JSH 2004, combination therapy with multiple agents is now being applied to many patients with hypertension. However, a pharmacoeconomic analysis of each therapy has not been fully undertaken in Japan, despite increasing societal interest. In this study, the cost-effectiveness of two calcium channel blockers, each coadministered with an angiotensin receptor blockade, was compared using data from the ADVANCE-Combi study. The ADVANCE-Combi study was a 16-week double-blind, randomized clinical trial to compare the efficacy and safety of two combination therapies (controlled-release nifedipine [nifedipine CR] plus valsartan vs. amlodipine plus valsartan) on blood pressure (BP) control in patients with moderate to severe essential hypertension. The incremental cost effectiveness of each cohort was compared from the perspective of insurers. The average total cost per patient was Japanese yen (JPY) 31,615 for the nifedipine CR treatment group and JPY 35,399 for the amlodipine treatment group (p < 0.001). The achievement rate of the target BP (SBP/DBP < 130/85 mmHg for patients aged under 60 years; SBP/DBP < 140/90 mmHg for those aged 60 years and over) was significantly higher in the nifedipine CR treatment group (61.2%) than in the amlodipine treatment group (34.6%) (p < 0.001), with no difference in the incidence of drug-related adverse events. Accordingly, the base case economic analysis demonstrated that the nifedipine CR treatment group was dominant (more efficacious and less costly) to the amlodipine treatment group. This result was supported by univariate and probabilistic sensitivity analyses. These results indicate that nifedipine CR-based combination therapy is superior to amlodipine-based combination therapy for the management of essential hypertension in the Japanese population.

Cost-effectiveness of irbesartan 300 mg given early versus late in patients with hypertension and a history of type 2 diabetes and renal disease: a Canadian perspective.

BACKGROUND: The Irbesartan in Reduction of Microalbuminuria trial and the Irbesartan in Diabetic Nephropathy Trial found that irbesartan is renoprotective in patients having hypertension with type 2 diabetes. OBJECTIVE: The objective of this study was to assess whether treatment with irbesartan is cost-effective in Canada relative to conventional care in this patient population and whether it is more cost-effective to treat patients early rather than later in the development of renal disease from the perspective of the Canadian health and social care system. METHODS: The analysis compared 3 alternative strategies for the management of hypertension in patients with type 2 diabetes and early renal disease: (1) conventional hypertensive treatment excluding the use of angiotensin II receptor antagonists (AIIRAs); (2) the early addition of irbesartan (an AIIRA) to conventional treatment; and (3) the late addition of irbesartan to conventional treatment. A Markov model was used to simulate the progression of renal disease (microalbuminuria to death) in hypertensive patients with type 2 diabetes over a 25-year time horizon. Transition probabilities were derived from the 2 randomized controlled trials. A cost-effectiveness analysis was conducted with outcome measured in life-years gained (LYGs). RESULTS: The early addition of irbesartan during microalbuminuria was cost-saving and more effective than both delaying irbesartan treatment until advanced overt nephropathy (AON) (0.45 LYG, Can $54,100 saved) and conventional antihypertensive use (0.62 LYG, $68,400 saved). This was due to the increased drug costs associated with the use of irbesartan being offset by savings arising from delays in the development of overt nephropathy and the subsequent delay to end-stage renal disease (ESRD). Sensitivity analyses confirmed the robustness of the study results. CONCLUSIONS: The early use of irbesartan for patients with hypertension and type 2 diabetes who have yet to develop overt nephropathy is both more effective and less costly than delaying irbesartan treatment until AON and conventional antihypertensive use. Analysis suggests that the earlier irbesartan is added to conventional antihypertensive treatment, the greater the delays in the onset of ESRD and the overall savings in health care resource utilization from the perspective of the Canadian health and social care system.

Controlled release nifedipine and valsartan combination therapy in patients with essential hypertension: the adalat CR and valsartan cost-effectiveness combination (ADVANCE-combi) study.

This study was designed to compare the clinical efficacy of two calcium channel blocker-based combination therapies with an angiotensin receptor blocker in Japanese patients with essential hypertension. A 16-week, double-blind, parallel-arm, randomized clinical trial was performed to compare the efficacy and safety of the combination therapy of controlled release nifedipine (nifedipine CR) plus valsartan vs. that of amlodipine plus valsartan. The primary endpoint was the target blood pressure achievement rate. Eligible patients were randomly allocated to nifedipine CR-based or amlodipine-based treatment groups. Patients were examined every 4 weeks to determine whether the blood pressure had reached the target level. When the target level was not achieved, the drug regimen was changed; when the target blood pressure was achieved, the same study medication was continued. A total of 505 patients were enrolled in the study (nifedipine CR group: 245 cases; amlodipine group: 260 cases). After 16 weeks of treatment, blood pressure was significantly reduced in both groups, but to a larger extent in the nifedipine CR group than in the amlodipine group (p < 0.01). The target blood pressure achievement rate was also significantly higher in the nifedipine CR group (p < 0.001). There was no significant difference in the incidence of drug-related adverse events between the groups. These results indicate that the nifedipine CR-based combination therapy was superior to the amlodipine-based therapy for decreasing blood pressure and achieving the target blood pressure in patients with essential hypertension.

Cost-effectiveness analysis of hypertension treatment: controlled release nifedipine and candesartan low-dose combination therapy in patients with essential hypertension--the Nifedipine and Candesartan Combination (NICE-Combi) Study.

Societal interest in pharmaco-economic analysis is increasing in Japan. In this study, the cost-effectiveness of low-dose combination therapy with controlled release nifedipine plus candesartan and up-titrated monotherapy with candesartan was estimated, based on the results of the NICE-Combi study. The NICE-Combi study was a double-blind, parallel arm, randomized clinical trial to compare the efficacy of low-dose combination therapy of controlled release nifedipine (20 mg/day) plus candesartan (8 mg/day) vs. up-titrated monotherapy of candesartan (12 mg/day) on blood pressure control in Japanese patients with mild to severe essential hypertension who were not sufficiently controlled by the conventional dose of candesartan (8 mg/ day). The incremental cost effectiveness of each cohort during the 8-week randomization period was compared, from the perspective of a third-party payer (i.e., insurers). The average total cost per patient was 29,943 Japanese yen for the combination therapy group and 33,182 Japanese yen for the candesartan monotherapy group, while the rate of achievement of the target blood pressure was significantly higher in the combination therapy group than in the up-titrated monotherapy group. In the combination therapy group, higher efficacy and lower incremental treatment cost ("Dominance") were observed when compared to the monotherapy group. The sensitivity analyses also supported the results. In conclusion, these results suggest that combination therapy with controlled release nifedipine and low-dose candesartan (8 mg) is "dominant" to up-titrated candesartan monotherapy for the management of essential hypertension. This conclusion was robust to sensitivity analysis.