Hypertension is a chronic, non-communicable disease that constitutes one of the most significant global public health challenges of the 21st century. The Global Burden of Disease Study estimated that elevated systolic blood pressure was responsible for approximately 10.8 million deaths worldwide in 2019, making it the leading metabolic risk factor for disability-adjusted life years [1]. In India, the prevalence of hypertension has increased substantially over the past two decades, with recent epidemiological surveys reporting an overall prevalence of 25–30% among adults, with significant urban-rural gradients [2].

The pathophysiology of essential hypertension is multifactorial, involving the interplay of genetic predisposition, the renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system overactivity, endothelial dysfunction, oxidative stress, and renal sodium handling abnormalities [3]. Current international and national guidelines, including those from the Joint National Committee (JNC 8), the European Society of Cardiology/European Society of Hypertension (ESC/ESH 2018), and the Indian Guidelines on Hypertension (IGH-IV), recommend initiating pharmacotherapy when lifestyle modifications fail to achieve blood pressure targets [4,5].

Among the five major classes of first-line antihypertensive agents — angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), calcium channel blockers (CCBs), beta-blockers, and thiazide diuretics — ARBs and CCBs have gained particular prominence due to their efficacy, tolerability, and end-organ protective properties [6]. Telmisartan is a long-acting, highly lipophilic ARB with a plasma half-life of approximately 24 hours, providing sustained 24-hour blood pressure control with once-daily dosing. Beyond its antihypertensive properties, telmisartan possesses unique partial peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist activity, which confers potential metabolic benefits including improved insulin sensitivity and favourable lipid modulation [7,8].

Amlodipine is a third-generation dihydropyridine CCB with a long plasma half-life (30–50 hours), providing consistent blood pressure reduction over 24 hours. The ALLHAT and VALUE trials demonstrated the robust antihypertensive efficacy and cardiovascular protective effects of amlodipine, particularly in reducing stroke risk [9,10]. However, dose-dependent peripheral edema remains a significant limitation affecting patient adherence [11].

While several randomised controlled trials have compared these two agents in Western populations, there is a relative paucity of prospective data comparing their real-world effectiveness, metabolic impact, and tolerability profile in Indian patients, who exhibit distinct genetic, dietary, and metabolic characteristics [12]. The Indian population is characterised by a higher prevalence of insulin resistance, central adiposity, and premature cardiovascular disease, which may influence the comparative effectiveness of different antihypertensive drug classes [13].

This prospective cohort study was designed to compare the antihypertensive efficacy, blood pressure target achievement rates, metabolic effects, and adverse effect profiles of telmisartan (40 mg) and amlodipine (5 mg) in patients with newly diagnosed essential hypertension at a tertiary care centre in Bangalore, India.

Study Design and Setting This was a prospective, open-label, parallel-group cohort study conducted at the Department of General Medicine, Shri Atal Bihari Vajpayee Medical College and Research Institute, Bangalore, India, over a period of 12 months from May 2025 to April 2026. Study Population Patients aged 18–65 years presenting to the outpatient department with newly diagnosed essential hypertension (systolic blood pressure [SBP] 140–179 mmHg and/or diastolic blood pressure [DBP] 90–109 mmHg on two separate occasions at least one week apart) were screened for eligibility. Inclusion Criteria The inclusion criteria were: (1) age 18–65 years; (2) newly diagnosed essential hypertension, Stage I (SBP 140–159 mmHg and/or DBP 90–99 mmHg) or Stage II (SBP 160–179 mmHg and/or DBP 100–109 mmHg) as per JNC 8 classification; (3) antihypertensive drug-naïve status; and (4) willingness to provide written informed consent and comply with the follow-up schedule. Exclusion Criteria Patients were excluded if they had: (1) secondary hypertension; (2) hypertensive emergency or urgency (SBP ≥180 mmHg and/or DBP ≥110 mmHg); (3) pre-existing cardiovascular disease (coronary artery disease, heart failure, valvular heart disease, or cerebrovascular disease); (4) diabetes mellitus (type 1 or type 2); (5) chronic kidney disease (eGFR <60 mL/min/1.73 m²); (6) hepatic dysfunction (ALT/AST >3× upper limit of normal); (7) known hypersensitivity to telmisartan or amlodipine; (8) pregnancy, lactation, or women of childbearing age not using reliable contraception; (9) concurrent use of medications known to affect blood pressure; or (10) any condition deemed by the investigator to preclude safe participation. Sample Size Calculation The sample size was calculated based on the primary outcome of mean SBP reduction at 24 weeks. Assuming a clinically meaningful difference of 4 mmHg between the two groups, a standard deviation of 10 mmHg (based on prior literature), a two-sided alpha of 0.05, and a statistical power of 80%, the minimum required sample size was 100 patients per group. Accounting for an anticipated dropout rate of 10%, a total of 220 patients (110 per group) were targeted for enrolment. Treatment Allocation and Protocol Patients were allocated to receive either telmisartan 40 mg once daily in the morning (Group T) or amlodipine 5 mg once daily in the morning (Group A) based on physician discretion, considering patient profile and clinical suitability. All patients received standardised lifestyle counselling including dietary sodium restriction (<5 g/day), regular physical activity (≥150 minutes/week of moderate-intensity exercise), weight management, smoking cessation, and moderation of alcohol intake. Dose up-titration was permitted after 8 weeks if blood pressure remained above target (telmisartan to 80 mg; amlodipine to 10 mg). Patients requiring dose escalation were documented but analysed in their original groups by intention-to-treat. Data Collection and Outcome Measures Clinical assessments were performed at baseline and at 4, 8, 12, and 24 weeks. At each visit, blood pressure was recorded as the mean of three readings taken 5 minutes apart, with the patient seated and after a 10-minute rest period, using a calibrated, validated digital sphygmomanometer (OMRON HEM-7130, Japan). An appropriately sized cuff was used based on mid-arm circumference. Heart rate was recorded concurrently. Body mass index (BMI) was calculated at baseline and 24 weeks. Laboratory investigations including fasting blood glucose, complete lipid profile (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides), serum creatinine, blood urea nitrogen, serum uric acid, serum electrolytes (sodium, potassium), and liver function tests were performed at baseline and at 24 weeks. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. The primary outcome was the change in SBP and DBP from baseline to 24 weeks. Secondary outcomes included: (1) the proportion of patients achieving target blood pressure (<140/90 mmHg) at each time point; (2) changes in heart rate; (3) changes in metabolic parameters (fasting blood glucose, lipid profile, serum uric acid); and (4) incidence and nature of adverse effects. Statistical Analysis Continuous variables were expressed as mean ± standard deviation (SD) and compared using the independent samples t-test or Mann-Whitney U test, as appropriate based on normality assessment by the Shapiro-Wilk test. Categorical variables were expressed as frequencies and percentages and compared using the chi-square test or Fisher's exact test. Within-group comparisons of blood pressure at different time points were performed using repeated measures ANOVA with Bonferroni correction. A two-tailed p-value of <0.05 was considered statistically significant. All statistical analyses were performed using IBM SPSS Statistics version 26.0 (IBM Corp., Armonk, NY, USA) and GraphPad Prism version 9.5 (GraphPad Software, San Diego, CA, USA).

Study Population

Of the 248 patients screened during the study period, 220 met the inclusion criteria and were enrolled (108 in the telmisartan group and 112 in the amlodipine group). Twenty-eight patients were excluded: 8 had secondary hypertension on evaluation, 6 had coexisting diabetes mellitus, 5 had eGFR <60 mL/min/1.73 m², 4 withdrew consent, 3 had hypertensive urgency at the baseline visit, and 2 had hepatic dysfunction. During the follow-up period, 10 patients were lost to follow-up (4 in the telmisartan group and 6 in the amlodipine group), yielding a final analytical cohort of 210 patients (telmisartan: n=104; amlodipine: n=106). The overall completion rate was 95.5%.

Baseline Characteristics

The baseline demographic and clinical characteristics of the two groups are summarised in Table 1. The groups were well-matched with respect to age, sex distribution, BMI, smoking and alcohol use, family history of hypertension, baseline blood pressure, heart rate, and all metabolic parameters (p>0.05 for all comparisons). The mean age of the study population was 48.2 ± 10.8 years, with a male predominance (60.0%). Approximately 63.8% of patients had Stage I hypertension, while 36.2% had Stage II hypertension.

Table 1. Baseline demographic and clinical characteristics of the study population

HTN = hypertension; BMI = body mass index; SBP = systolic blood pressure; DBP = diastolic blood pressure; FBG = fasting blood glucose; eGFR = estimated glomerular filtration rate. Values are mean ± SD or n (%). p-values by independent t-test or chi-square test.

Primary Outcome: Blood Pressure Reduction

Both treatment groups demonstrated statistically significant and progressive reductions in SBP and DBP from baseline through 24 weeks (within-group p<0.001 by repeated measures ANOVA for both parameters in both groups). The detailed blood pressure values at each time point are presented in Table 2.

In the telmisartan group, the mean SBP decreased from 152.4 ± 11.8 mmHg at baseline to 127.6 ± 7.3 mmHg at 24 weeks, representing a mean reduction of 24.8 ± 9.6 mmHg (16.3%). In the amlodipine group, the mean SBP decreased from 153.8 ± 12.4 mmHg to 125.8 ± 7.0 mmHg, corresponding to a mean reduction of 28.0 ± 10.4 mmHg (18.2%). The between-group difference in SBP reduction at 24 weeks was statistically significant (p=0.021), favouring amlodipine (Figure 1).

The mean DBP reduction at 24 weeks was 16.0 ± 6.8 mmHg (16.6%) in the telmisartan group and 17.4 ± 7.2 mmHg (17.9%) in the amlodipine group. This difference did not reach statistical significance (p=0.148). Figure 2 illustrates the DBP trajectory over the study period.

Table 2. Blood pressure values (mmHg, mean ± SD) at each time point

* p<0.05 between groups. † p-value for between-group comparison of change (Δ) from baseline to 24 weeks by independent t-test. Within-group change from baseline: p<0.001 for both SBP and DBP at all time points in both groups (repeated measures ANOVA with Bonferroni correction).

Figure 1. Mean systolic blood pressure (SBP) over the 24-week follow-up period. Error bars represent standard deviation. Amlodipine demonstrated a marginally greater SBP reduction, reaching statistical significance at Week 8 and for overall change from baseline (p=0.021).

Figure 2. Mean diastolic blood pressure (DBP) over the 24-week follow-up period. Error bars represent standard deviation. Both groups achieved comparable DBP reductions without statistically significant between-group differences at any time point.

Secondary Outcomes

Blood Pressure Target Achievement

The proportion of patients achieving the target blood pressure of <140/90 mmHg increased progressively in both groups over the 24-week period (Figure 3). At Week 4, 34.6% of telmisartan patients and 38.7% of amlodipine patients achieved the target (p=0.536). By Week 24, the rates were 82.7% and 85.8%, respectively (p=0.548). No statistically significant between-group differences were observed at any time point. Among patients with Stage II hypertension at baseline, target achievement at 24 weeks was 72.2% (26/36) in the telmisartan group and 77.5% (31/40) in the amlodipine group (p=0.578).

Figure 3. Proportion of patients achieving target blood pressure (<140/90 mmHg) at each follow-up visit. No statistically significant differences were observed between the two groups at any time point.

Metabolic Parameters

Table 3 presents the changes in metabolic parameters from baseline to 24 weeks. Telmisartan was associated with a statistically significant reduction in fasting blood glucose (−3.4 ± 4.8 mg/dL vs. +1.6 ± 5.2 mg/dL; p=0.032 for between-group comparison of change), triglycerides (−9.8 ± 12.4 mg/dL vs. −2.6 ± 8.6 mg/dL; p=0.044), and serum uric acid (−0.2 ± 0.4 mg/dL vs. +0.2 ± 0.6 mg/dL; p=0.038). A trend toward greater HDL cholesterol improvement was observed with telmisartan (+1.6 ± 3.2 mg/dL vs. +0.2 ± 2.8 mg/dL; p=0.082) but did not reach statistical significance. Changes in total cholesterol, LDL cholesterol, serum creatinine, and eGFR were comparable between groups.

The mean heart rate decreased modestly in the telmisartan group (−1.6 ± 3.4 bpm) while it increased slightly in the amlodipine group (+1.4 ± 3.8 bpm), with a statistically significant between-group difference (p=0.028).

Table 3. Metabolic parameters at baseline and 24 weeks (mean ± SD)

† p-value for between-group comparison of change from baseline to 24 weeks. * p<0.05. FBG = fasting blood glucose; eGFR = estimated glomerular filtration rate.

Adverse Effects

The adverse effect profiles of the two groups are detailed in Table 4 and illustrated in Figure 4. The overall incidence of adverse effects was significantly lower in the telmisartan group compared to the amlodipine group (21.2% vs. 34.0%; p=0.038). The most notable difference was in the incidence of peripheral edema, which was significantly more frequent with amlodipine (14.2% vs. 3.8%; p=0.011). Flushing was also significantly more common with amlodipine (7.5% vs. 1.0%; p=0.024). All reported adverse effects were of mild-to-moderate severity and did not necessitate treatment discontinuation. No serious adverse events, including hyperkalemia (serum potassium >5.5 mEq/L), acute kidney injury, or angioedema, were reported in either group.

Dose up-titration was required in 14 patients (13.5%) in the telmisartan group and 12 patients (11.3%) in the amlodipine group (p=0.634). No patient in either group required addition of a second antihypertensive agent during the study period.

Table 4. Adverse effects reported during the 24-week follow-up

* p<0.05 (chi-square test or Fisher's exact test). All adverse effects were of mild-to-moderate severity. No treatment discontinuation occurred due to adverse effects.

Figure 4. Comparison of adverse effect profiles between the two treatment groups. Peripheral edema and flushing were significantly more common in the amlodipine group. ** p<0.05; * p<0.05.

Figure 5. Waterfall plot depicting individual patient systolic blood pressure changes from baseline to 24 weeks. Each bar represents one patient. Orange bars indicate patients who did not achieve SBP reduction. The majority of patients in both groups experienced clinically meaningful SBP reductions.

This prospective cohort study provides a comprehensive head-to-head comparison of telmisartan 40 mg and amlodipine 5 mg as initial monotherapy for newly diagnosed essential hypertension in an Indian tertiary care setting. Our findings demonstrate that both agents are effective in reducing blood pressure, with comparable target achievement rates, but with important differences in their adverse effect and metabolic profiles that may guide individualised treatment decisions.

The primary finding of our study is that both telmisartan and amlodipine produced clinically meaningful and statistically significant reductions in SBP and DBP over the 24-week follow-up. Amlodipine demonstrated a marginally greater SBP reduction (28.0 vs. 24.8 mmHg; p=0.021), while DBP reductions were comparable. This observation aligns with findings from the ONTARGET trial, where telmisartan-treated patients had slightly higher mean blood pressures compared to the ramipril arm, despite comparable cardiovascular outcomes [14]. The slightly superior SBP reduction with amlodipine is consistent with its potent direct vasodilatory mechanism and the results of the ALLHAT trial, which demonstrated the robust blood pressure-lowering efficacy of amlodipine across diverse populations [9].

Despite the modest statistical difference in SBP reduction, the clinical significance of this finding is debatable, as the absolute difference of 3.2 mmHg may not translate into meaningful differences in cardiovascular outcomes, particularly given that both groups achieved comparable target blood pressure rates (82.7% vs. 85.8%; p=0.548). Previous studies by Sharma et al. (2014) and Neldam et al. (2004) similarly reported equivalent blood pressure control rates between ARBs and CCBs, even when absolute blood pressure reductions differed marginally [15,16].

A key strength of this study is the systematic evaluation of metabolic parameters. Telmisartan demonstrated statistically significant favourable effects on fasting blood glucose, triglycerides, and serum uric acid compared to amlodipine. These findings are attributable to telmisartan's unique partial PPAR-γ agonist activity, which has been demonstrated in both preclinical and clinical studies to enhance insulin sensitivity and modulate lipid metabolism [7,8]. The PPAR-γ activation by telmisartan is structurally mediated — unlike other ARBs, telmisartan's biphenyl-carboxylic acid moiety enables direct interaction with the PPAR-γ ligand-binding domain [17]. The metabolic benefits of telmisartan have significant clinical implications in the Indian population, where the prevalence of metabolic syndrome and insulin resistance is disproportionately high, and where antihypertensive agents with neutral or favourable metabolic profiles may offer additional cardiovascular risk reduction [13,18].

The adverse effect profile observed in our study is consistent with the established pharmacological profiles of both drugs. The significantly higher incidence of peripheral edema (14.2% vs. 3.8%) and flushing (7.5% vs. 1.0%) in the amlodipine group reflects its mechanism-related vasodilatory effects. Peripheral edema is a well-recognised dose-dependent side effect of dihydropyridine CCBs, resulting from preferential arteriolar dilatation and increased transcapillary hydrostatic pressure, rather than sodium retention [11]. In the ACCOMPLISH trial, peripheral edema was the most common cause of amlodipine discontinuation [19]. The superior tolerability profile of telmisartan observed in our study supports findings by Lacourcière et al. (2003) and Williams et al. (2006), who reported lower rates of treatment-emergent adverse events with ARBs compared to CCBs [20,21].

The modest heart rate reduction observed with telmisartan (−1.6 bpm) compared to the slight increase with amlodipine (+1.4 bpm) may be clinically relevant, as elevated resting heart rate is an independent cardiovascular risk factor. This difference may be mediated by the inhibitory effect of angiotensin II blockade on sympathetic nervous system activity and baroreflex sensitivity [22].

Limitations

This study has several limitations that warrant consideration. First, the open-label, non-randomised design introduces the potential for selection and observer bias, although the well-matched baseline characteristics of the two groups mitigate this concern to some extent. Second, the 24-week follow-up period, while adequate for assessing blood pressure control and short-term tolerability, is insufficient to evaluate long-term cardiovascular outcomes or renal protective effects. Third, the single-centre design limits the generalisability of findings to other healthcare settings and populations. Fourth, while dose titration was permitted, the starting doses of telmisartan 40 mg and amlodipine 5 mg represent mid-range doses, and the comparative efficacy at maximal doses was not systematically evaluated. Fifth, 24-hour ambulatory blood pressure monitoring was not performed, which would have provided additional information on blood pressure variability and nocturnal dipping patterns. Finally, the study did not assess medication adherence using objective measures such as pill counts or electronic monitoring devices, relying instead on patient self-report.

Strengths

The strengths of this study include its prospective design, comprehensive metabolic assessment, systematic adverse effect documentation, adequate sample size, high completion rate (95.5%), and standardised blood pressure measurement protocol using validated automated devices. The study also provides real-world effectiveness data in an Indian population, which is underrepresented in landmark hypertension trials.

This prospective cohort study demonstrates that both telmisartan 40 mg and amlodipine 5 mg are effective first-line antihypertensive agents in patients with newly diagnosed essential hypertension, achieving comparable blood pressure target rates of approximately 83–86% at 24 weeks. Amlodipine produced a marginally greater systolic blood pressure reduction, while telmisartan exhibited a superior tolerability profile with significantly fewer vasodilatory adverse effects (peripheral edema, flushing) and demonstrated favourable metabolic effects on fasting blood glucose, triglycerides, and serum uric acid — attributes particularly relevant in the Indian population characterised by a high prevalence of metabolic syndrome. The choice between telmisartan and amlodipine should be individualised, taking into account patient comorbidities (particularly metabolic syndrome, insulin resistance, and diabetes risk), tolerability concerns, and the overall cardiovascular risk profile. Telmisartan may be preferred in patients with metabolic risk factors or those prone to peripheral edema, while amlodipine remains an excellent choice when maximal blood pressure reduction is the primary therapeutic goal. Larger, multicentre, randomised controlled trials with longer follow-up periods and hard cardiovascular endpoints are warranted to definitively establish the comparative long-term benefits of these two agents in Indian patients with essential hypertension.

1. GBD 2019 Risk Factors Collaborators. Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020;396(10258):1223-1249.
2. Anchala R, Kannuri NK, Pant H, et al. Hypertension in India: a systematic review and meta-analysis of prevalence, awareness, and control of hypertension. J Hypertens. 2014;32(6):1170-1177.
3. Oparil S, Acelajado MC, Bakris GL, et al. Hypertension. Nat Rev Dis Primers. 2018;4:18014.
4. James PA, Oparil S, Carter BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA. 2014;311(5):507-520.
5. Williams B, Mancia G, Spiering W, et al. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39(33):3021-3104.
6. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. J Am Coll Cardiol. 2018;71(19):e127-e248.
7. Benson SC, Pershadsingh HA, Ho CI, et al. Identification of telmisartan as a unique angiotensin II receptor antagonist with selective PPARgamma-modulating activity. Hypertension. 2004;43(5):993-1002.
8. Vitale C, Mercuro G, Castiglioni C, et al. Metabolic effect of telmisartan and losartan in hypertensive patients with metabolic syndrome. Cardiovasc Diabetol. 2005;4:6.
9. ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic: the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA. 2002;288(23):2981-2997.
10. Julius S, Kjeldsen SE, Weber M, et al. Outcomes in hypertensive patients at high cardiovascular risk treated with regimens based on valsartan or amlodipine: the VALUE randomised trial. Lancet. 2004;363(9426):2022-2031.
11. Sica DA. Calcium channel blocker-related peripheral edema: can it be resolved? J Clin Hypertens (Greenwich). 2003;5(4):291-294.
12. Gupta R, Gaur K, Ram CV. Emerging trends in hypertension epidemiology in India. J Hum Hypertens. 2019;33(8):575-587.
13. Joshi SR, Anjana RM, Deepa M, et al. Prevalence of dyslipidemia in urban and rural India: the ICMR-INDIAB study. PLoS One. 2014;9(5):e96808.
14. Yusuf S, Teo KK, Pogue J, et al. Telmisartan, ramipril, or both in patients at high risk for vascular events. N Engl J Med. 2008;358(15):1547-1559.
15. Sharma AM, Bakris G, Neutel JM, et al. Single-pill combination of telmisartan/amlodipine versus amlodipine monotherapy in diabetic hypertensive patients: an 8-week randomized, parallel-group, double-blind trial. Clin Ther. 2014;36(11):1518-1531.
16. Neldam S, Lang M, Jones R; ATHOS Study Group. Telmisartan and amlodipine single-pill combinations vs amlodipine besylate as first-line therapy in black patients with stage 1 and 2 hypertension. J Hum Hypertens. 2012;26(4):244-251.
17. Schupp M, Clemenz M, Ginber R, et al. Molecular characterization of new selective peroxisome proliferator-activated receptor gamma modulators with angiotensin receptor blocking activity. Diabetes. 2005;54(12):3442-3452.
18. Misra A, Khurana L. Obesity-related non-communicable diseases: South Asians vs White Caucasians. Int J Obes (Lond). 2011;35(2):167-187.
19. Jamerson K, Weber MA, Bakris GL, et al. Benazepril plus amlodipine or hydrochlorothiazide for hypertension in high-risk patients. N Engl J Med. 2008;359(23):2417-2428.
20. Lacourcière Y, Poirier L, Lefebvre J, et al. Antihypertensive effects of amlodipine and hydrochlorothiazide in elderly patients with ambulatory hypertension. Am J Hypertens. 2003;16(12):1033-1038.
21. Williams B, Lacy PS, Thom SM, et al. Differential impact of blood pressure-lowering drugs on central aortic pressure and clinical outcomes: principal results of the Conduit Artery Function Evaluation (CAFE) study. Circulation. 2006;113(9):1213-1225.
22. Siragy HM, Xue C, Webb RL. Beneficial effects of combined benazepril-amlodipine on cardiac nitric oxide, cGMP, and TNF-alpha production after cardiac ischemia. J Cardiovasc Pharmacol. 2006;47(5):636-642.