Enalapril and nifedipine in the treatment of mild to moderate essential hypertension: a 6 month comparison

Meta-analysis of randomized trials of angioedema as an adverse event of renin-angiotensin system inhibitors

Angioedema is a rare, potentially life-threatening adverse event of renin-angiotensin system inhibitors. The objective of the present study was to determine the risk of angioedema from randomized clinical trials. A PubMed/CENTRAL/EMBASE search was made for randomized clinical trials from 1980 to October 2011 in patients on angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), or direct renin inhibitor (DRI). Trials with a total number of patients ≥100 and a duration of ≥8 weeks were included for analysis. Incidence of angioedema was pooled by weighing the incident rate of each trial by the inverse of the variance. Twenty-six trials with 74,857 patients in the ACE inhibitor arm with 232,523 person-years of follow-up, 19 trials with 35,479 patients on ARB with 122,293 person-years of follow-up, and 2 trials with 5,141 patients on DRI with 1,735 person-years of follow-up met the inclusion criteria and were included in the analysis. In head-to-head comparison in 7 trials, risk of angioedema with ACE inhibitors was 2.2 times higher than with ARBs (95% confidence interval [CI] 1.5 to 3.3). With ACE inhibitors and ARBs, incidence of angioedema was higher in heart failure trials compared to hypertension or coronary artery disease trials without heart failure (p <0.0001). Weighted incidence of angioedema with ACE inhibitors was 0.30% (95% CI 0.28 to 0.32) compared to 0.11% (95% CI 0.09 to 0.13) with ARBs, 0.13% (95% CI 0.08 to 0.19) with DRIs, and 0.07% with placebo (95% CI 0.05 to 0.09). In conclusion, incidence of angioedema with ARBs and DRI was <1/2 than that with ACE inhibitors and not significantly different from placebo. Incidence of angioedema was higher in patients with heart failure compared to those without heart failure with ACE inhibitors and ARBs.

Nifedipine versus carvedilol in the treatment of de novo arterial hypertension after liver transplantation: results of a controlled clinical trial

The aim of this study was to compare nifedipine and carvedilol in the treatment of de novo arterial hypertension after orthotopic liver transplantation (OLT). The study included 50 patients who developed arterial hypertension after OLT. Twenty-five patients received nifedipine (group A), and 25 received carvedilol (group B). Patients were defined as intolerant to nifedipine or carvedilol if severe adverse effects developed. These patients stopped the first drug and were switched to the other one. Patients were defined as full responders to monotherapy if there was normalization of blood pressure, and they were defined as partial responders by the need to add a second antihypertensive drug, ramipril. The 2 groups of patients were similar for baseline conditions. At the end of the study, patients intolerant to monotherapy were 48% of group A and 12.5% of group B (P < 0.01). Full responders were 20% of group A and 33.33% of group B (P < 0.01). Partial responders were 22% of group A and 54.1% of group B (P < 0.01). The addition of ramipril normalized blood pressure in 19% of partial responders to monotherapy (75% in partial responders to nifedipine and 30% in partial responders to carvedilol, P < 0.01). In responders to either monotherapy or combined therapy, there was a significant improvement of renal function. In responders to carvedilol, but not in responders to nifedipine, the daily dose of tacrolimus at 1 year should be reduced to 50% compared to the baseline dose to maintain the blood trough level in the therapeutic range.

Clinical efficacy and safety of telmisartan 80 mg once daily compared with enalapril 20 mg once daily in patients with mild-to-moderate hypertension: results of a multicentre study

The efficacy and safety of once-daily telmisartan 80 mg vs. once-daily enalapril 20 mg in the treatment of essential hypertension were evaluated in a multicentre, single-blind, placebo-controlled, randomised trial. In total, 68 patients (49 females, 19 males) with mild-to-moderate hypertension, defined as morning supine systolic blood pressure (SBP) 141-149 mmHg, diastolic blood pressure (DBP) 95-114 mmHg, were enrolled. After a 4-week placebo run-in phase, patients were randomly assigned to treatment with telmisartan or enalapril administered once daily in the morning for 8 weeks. No statistically significant differences were found in the baseline characteristics of patients in either group. Both SBP and DBP were decreased in both treatment groups, but the reductions were statistically different in favour of telmisartan (SBP, p = 0.013; DBP, p = 0.002). The incidence of adverse effects was lower in the telmisartan group, with the absence of cough. In conclusion, telmisartan is more effective and better tolerated than enalapril for the treatment of hypertension and has the advantage that it does not cause cough.

ACE inhibitor-induced angioedema. Incidence, prevention and management

Available information from 1980 to 1997 on angiotensin converting enzyme (ACE) inhibitor-induced angioedema and its underlying mechanisms are summarised and discussed. The incidence of angioedema is low (0.1 to 0.2%) but can be considered as a potentially life-threatening adverse effect of ACE inhibitor therapy. This adverse effect of ACE inhibitors, irrespective of the chemical structure, can occur early in treatment as well as after prolonged exposure for up to several years. The estimate incidence is quite underestimated. The actual incidence can be far higher because of poorly recognised presentation of angioedema as a consequence of its late onset in combination with usually long term therapy. Also, a spontaneous reporting bias can contribute to an actual higher incidence of this phenomenon. The incidence can be even higher (up to 3-fold) in certain risk groups, for instance Black Americans. Treatment includes immediate withdrawal of the ACE inhibitor and acute symptomatic supportive therapy followed by immediate (and long term) alternative therapy with other classes of drugs to manage hypertension and/or heart failure. Preclinical and clinical studies for the elucidation of the underlying mechanism(s) of ACE inhibitor-associated angioedema have not generated definite conclusions. It is suggested that immunological processes and several mediator systems (bradykinin, histamine, substance P and prostaglandins) are involved in the pathogenesis of angioedema. A great part of all reviewed reports suggest a relationship between ACE inhibitor-induced angioedema and increased levels of (tissue) bradykinin. However, no conclusive evidence of the role of bradykinin in angioedema has been found and an exclusive role of bradykinin seems unlikely. So far, no clear-cut evidence for an immune-mediated pathogenesis has been found. In addition, ACE gene polymorphism and some enzyme deficiencies are proposed to be involved in ACE inhibitor-induced angioedema. Progress in pharmacogenetic and molecular biological research should throw more light on a possible genetic component in the pathogenesis of ACE inhibitor-associated angioedema.

Safety of nifedipine in patients with hypertension: a meta-analysis

Our objective was to compare cardiovascular event rates in patients with mild or moderate hypertension who received nifedipine with active drug controls. We performed a MEDLARS search using the MeSH heading "hypertension" and the text word "nifedipine" to identify all articles that were published between 1966 and August 1995 in English, French, German, Italian, and Spanish languages and that involved human subjects. The computerized search was supplemented by a manual search of article bibliographies. Review of 1880 citations revealed 98 randomized controlled clinical trials that met protocol criteria. Articles were extracted independently by two doctors who were blinded for author, institution, and treatment regimen, using a structured, pretested extraction form. Differences of opinion were resolved by consensus. Fourteen events occurred in 5198 exposures (0.27%) to nifedipine and 24 events in 5402 exposures (0.44%) to other active drug controls. Unadjusted odds ratios for nifedipine versus controls were 0.49 (95% confidence interval [CI], 0.22-1.09) for definitive events (death, nonfatal myocardial infarction or stroke, revascularization procedure) and 0.61 (95% CI, 0.31-1.17) for all events (definitive plus increased angina). The odds ratio for nifedipine monotherapy (sustained- or extended-release in 91% of exposures) was nonsignificantly higher for definitive and all events (odds ratio, 1.40; 95% CI, 0.49-4.03 and odds ratio, 1.39; 95% CI, 0.59-3.32, respectively). The odds ratio for nifedipine in combination with another drug was significantly lower for definitive and all events (odds ratio, 0.09; 95% CI, 0.01-0.66 and odds ratio, 0.15; 95% CI, 0.03-0.65, respectively). Differences in odds ratio for nifedipine monotherapy and combined therapy were statistically significant (P=.02 for definitive events and P=.001 for all events). Results support the safety of sustained- and extended-release nifedipine in the treatment of mild or moderate hypertension when it is used in combination with other drugs.

Comparative effects of fosinopril and nifedipine on regression of left ventricular hypertrophy in hypertensive patients: a double-blind study

The effects of fosinopril and nifedipine on left ventricular (LV) mass were evaluated in 35 hypertensive patients with LV mass index greater than 110 g/m2 in female and 130 g/m2 in male patients. The goal of therapy was also to obtain a seated diastolic blood pressure (SDBP) of less than 90 mmHg. The patients were studied by echocardiography after 2 weeks of placebo treatment and 4, 12, and 24 weeks of monotherapy with active drugs. Both fosinopril and nifedipine reduced SDBP to a normal level after 6 months of treatment (p < .001). Regression of LV hypertrophy was achieved by either agent (p < .001), with fosinopril being more effective than nifedipine (p < .002). In conclusion, both fosinopril and nifedipine effectively reduce SDBP and achieve important regression of LV hypertrophy.

Enalapril. A reappraisal of its pharmacology and therapeutic use in hypertension

Enalapril, an angiotensin converting enzyme (ACE) inhibitor usually administered orally once daily, decreases blood pressure by lowering peripheral vascular resistance without increasing heart rate or output. It is effective in lowering blood pressure in all grades of essential and renovascular hypertension. Patients not responding adequately to enalapril monotherapy usually respond with the addition of a thiazide diuretic (or a calcium antagonist or beta-blocker), and rarely require a third antihypertensive agent. Enalapril is at least as effective as other established and newer ACE inhibitors, and members of other antihypertensive drug classes including diuretics, beta-blockers, calcium antagonists and alpha-blockers, but therapy with enalapril may be less frequently limited by serious adverse effects or treatment contraindications than with other drug classes. The most frequent adverse effect limiting all ACE inhibitor therapy in clinical practice is cough. This favourable profile of efficacy and tolerability, and the substantial weight of clinical experience, explain the increasing acceptance of enalapril as a major antihypertensive treatment and supports its use as logical first-line therapeutic option.

Cough and enalapril: assessment by spontaneous reporting and visual analogue scale under double-blind conditions

The incidence and prevalence of cough related to enalapril was assessed by spontaneous reporting and a visual analogue scale during a 6 month random double-blind parallel-group study comparing enalapril with nifedipine. Cough was reported spontaneously by 6.2% of enalapril-treated patients, and by none on nifedipine (NS). No patient had to discontinue enalapril because of cough. After 24 weeks treatment increases in visual analogue scale scores for cough frequency greater than or equal to 8 mm were more common for enalapril than nifedipine (difference 21.5%, 95% CI 7.3-35.7%). Increased cough frequency by visual analogue scale was present throughout the study in women, but less consistently in men. High scores for cough were not related to the dose of enalapril. Cough with enalapril was not an important problem during the 6 months of treatment. However increased cough frequency could be detected by visual analogue scale, with a frequency consistent with that observed in open clinic-based studies of longer duration. These findings suggest that ACE inhibitor-induced cough may increase in severity over time, and that even a period of 6 months treatment is too short to evaluate this side-effect adequately.