Combination therapy as first-line treatment for hypertension

Alagebrium (ALT-711) improves the anti-hypertensive efficacy of nifedipine in diabetic-hypertensive rats

Combining drugs with complementary mechanisms of action may contribute to improved hypertension control in diabetic patients. Advanced glycation end-product (AGE) breakers, a new class of candidate drugs targeting aging-related cardiovascular dysfunction, may be useful as novel adjuvant agents to improve the efficacy of diabetic hypertension (DH) treatment. This study evaluated the effects of alagebrium (ALT-711), an AGE breaker, combined with nifedipine, a Ca(2+) channel blocker, in a rat model of streptozotocin-induced DH. Compared with monotherapy, combination treatment significantly decreased systolic and diastolic blood pressure values, increased the pulse pressure, and decreased the coefficient of variation of the systolic blood pressure. Plasma biochemistry indicated that the concentrations of prostacyclin and nitric oxide were increased. Gene expression analysis showed significantly decreased prepro-endothelin-1expression in the aorta. These results reveal that alagebrium significantly improves the anti-hypertensive actions of nifedipine in a rat model of DH and suggest its potential use in the successful control of clinical DH.

Prediction of adverse events by in vivo gene expression profiling exemplified for phytopharmaceuticals containing salicylates and the antidepressant imipramine

BACKGROUND AND OBJECTIVE

Gene expression profiles of Sprague-Dawley (SD) rats treated with a standardized willow bark extract (WB), its salicin rich ethanol fraction (EtOH-FR) or the tricyclic antidepressant imipramine were evaluated for their potential to induce adverse events. Treatments had shown antidepressant-like effects.

METHODS

Gene expression profiles (Agilent Whole Genome Array, n=4/group) obtained from the peripheral blood of male SD rats treated with WB (STW 33-I), EtOH-FR (30 mg/kg bw) or imipramine (20 mg/kg bw) were analysed comparatively by the Ingenuity Systems Programme, which allows to conduct model calculations of thresholds for theoretical potential adverse events (AE).

RESULTS

The number of genes regulated by the three treatments were 1673 (WB), 117 (EtOH-FR) and 1733 (imipramine). The three treatments related to 47 disease clusters. The WB extract reached the threshold for a potential AE in one disease cluster (cardiac hypertrophy), whereas the EtOH-FR exceeded the threshold in 5 disease clusters (cardiac arteriopathy and stenosis, glomerular injury, pulmonary hypertension, alkaline phosphatase levels ⇑). Imipramine treatment hit 13 disease clusters: tachycardia, palpitation, myocardial infarction, arrhythmias, heart block, precipitation of congestive heart failure; urinary retention, altered liver functions. Those correspond to known potential adverse events. Glomerular injury and altered liver functions are part of the side effect profile of salicylic acid derivatives in agreement with the findings for the salicin rich EtOH-FR.

CONCLUSION

There is no linear relationship between the number of constituents of a drug (preparation) and the number of different targets hit in a biological system on the gene expression level. Therefore, the number of genetic targets in a biological system does not necessarily increase with the complexity of the treatment corresponding to the non-linear behaviour of biological systems. Regarding gene expression levels AE of single treatments are not necessarily additive in combination treatments. The applied method appears to be an interesting screening tool for the prediction of potential AE. The phenomena that imipramine crossed the potential threshold for AEs several times whereas the WB extract did reach the threshold level only once, however not backed by clinical data for this AE, deserves to be further investigated. It questions the commonly assumed principle that substances with low number or without AE will have a poor efficacy.

Effectiveness and safety of high-dose valsartan monotherapy in hypertension treatment: the ValTop study

Early combination therapy is increasingly recommended in hypertension management because of increased risk of adverse effects with high-dose monotherapy. However, this risk is not necessarily increased for high doses of angiotensin receptor blockers (ARB). ValTop study compared efficacy and safety of high vs. conventional dose of valsartan in hypertensive patients. ValTop was a controlled, randomized, double-blind trial. Of 6035 screened subjects, 4004 mild-to-moderate hypertensive patients (mean seated diastolic blood pressure (MSDBP) 90-109 mm Hg) started 4-week open-label treatment with valsartan 160 mg. Of them, 3776 were randomized to receive valsartan 160 mg (N=1900) or 320 mg (N=1876) o.d. for 4 weeks. In 28-week open-label extension study, all participating patients (N=642) received valsartan 320 mg. Valsartan 160 mg reduced MSDBP by 10.0 mm Hg in the initial open-label phase. Further BP reductions in the double-blind phase were significantly (P<0.0001) greater in the 320 mg group than in the 160 mg group for MSDBP (1.6 ± 0.18 mm Hg vs. 0.5 ± 0.18 mm Hg) and mean seated systolic BP (3.3 ± 0.31 mm Hg vs. 0.7 ± 0.31 mm Hg). The size of the additional effect of the 320 mg dose on BP was similar in subjects controlled or not by the initial 160 mg dose. Adverse event (AE) rates were similar in both treatment groups, drug-related AEs occurring in <5% of subjects in each phase. High-dose valsartan is safe and effective in uncomplicated mild-to-moderate hypertension independently of the initial response to a moderate dose. High-dose ARB monotherapy may thus be a viable option in hypertension management.

Efficacy and safety of the single pill combination of amlodipine 10 mg plus valsartan 160 mg in hypertensive patients not controlled by amlodipine 10 mg plus olmesartan 20 mg in free combination

BACKGROUND AND OBJECTIVE

For patients with moderate hypertension (grade 2, defined as systolic blood pressure [SBP] 160-179 mmHg and/or diastolic blood pressure [DBP] 100-109 mmHg), current guidelines recommend initial combination therapy and rapid dose-adjustment to achieve blood pressure goal. In this study we investigated the efficacy and tolerability of the single pill combination of amlodipine 10 mg plus valsartan 160 mg (A 10 + Val 160) in patients not controlled by the free combination of amlodipine 10 mg plus olmesartan 20 mg (A 10 + O 20).

METHODS

In this prospective, open-label, non-randomized trial, 257 patients with mean sitting DBP of 100-109 mmHg at trough entered a 4 week treatment phase with A 10 + O 20 in free combination once daily. Patients in whom DBP remained uncontrolled were switched in a second 4 week treatment phase to A 10 + Val 160. The primary efficacy variable was the reduction in DBP at week 8 compared to week 4 in the intent-to-treat population.

RESULTS

In the total cohort, baseline SBP/DBP of 164.2 +/- 9.8/103.6 +/- 2.1 mmHg decreased by 19.2 +/- 12.4/14.1 +/- 7.4 mmHg at week 4. In patients who did not achieve BP control (n = 175), subsequent treatment with A 10 + Val 160 for 4 weeks reduced SBP from 149.6 +/- 11.1 at week 4 by 7.9 mmHg at week 8 (95% CI: 6.1-9.6, p < 0.0001) and DBP from 93.4 +/- 3.9 mmHg by 9.1 mmHg (95% confidence interval: 8.1-10.2, p < 0.0001). The combination of A 10 + Val 160 was well tolerated, and the observed adverse events (15.3% of patients in phase 2) were consistent with the known drug profiles.

CONCLUSIONS

In a study designed to reflect typical clinical practice, in patients not controlled by the free combination of A 10 + O 20, the single pill combination of A 10 + Val 160 produced a statistically and clinically significant additional BP reduction and was well tolerated. Potential limitations of the design (open-label, non-controlled design, short term treatment) have to be taken into account.

Emerging insights in the first-step use of antihypertensive combination therapy

The blood pressure (BP) goals set by hypertension management guidelines (<140/90 mm Hg in uncomplicated hypertension; <130/80 mm Hg in type 2 diabetes or kidney disease) are not being achieved in a high proportion of patients, partly because monotherapy is insufficient in many patients. In particular, patients with uncontrolled moderate or severe hypertension and/or associated cardiovascular risk factors remain at high risk for cardiovascular events and hypertensive emergency. In recognition of the urgency of treating moderate and severe hypertension, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) advocates the initial use of 2-drug therapies in patients with systolic BP levels >20 mm Hg above goal or diastolic BP level >10 mm Hg above goal. Regimens should usually include a thiazide diuretic and, for patients with diabetes or kidney disease, an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Recently, clinical trial data have shown that first-step antihypertensive treatment of moderate and severe hypertension with carefully chosen fixed-dose combinations provides a high rate of BP goal achievement, a simplified dosing regimen, and superior tolerability compared with monotherapy.

Fixed-Drug Combinations as First-Line Treatment for Hypertension

As combinations of drugs from different classes that have synergistic or additive effect and properties to cancel out each others' untoward hemodynamic and metabolic effects become more and more widely used, their use as first-line therapy for the treatment of newly diagnosed hypertensive patients is growing in popularity as well. The possibility to begin therapy with a fixed 2-drug combination may be preferable to starting with monotherapy followed by upward titration and addition of other agents. More and more combinations are coming out on the market and proving their effectiveness in randomized controlled trials and in large multicenter studies. One suggestion is the "polypill," a fixed combination of multiple agents that address various components of the metabolic syndrome and coexisting common risk factors in both high-risk patients with conditions requiring polypharmacy, and in healthy asymptomatic individuals.

Insights from molecular investigations of traditional Chinese herbal stroke medicines: implications for neuroprotective epilepsy therapy

Traditional Chinese herbal medicine is the most widely practiced form of herbalism worldwide. It is based on a sophisticated system of medical theory and practice that is distinctly different from orthodox Western scientific medicine. Most traditional therapeutic formulations consist of a combination of several drugs. The combination of multiple drugs is thought to maximize therapeutic efficacy by facilitating synergistic actions and ameliorating or preventing potential adverse effects while at the same time aiming at multiple targets. Orthodox drug therapy has been subject to critical analysis by the "evidence-based medicine" movement, and demands have been made that herbal medicine should be subject to the same kind of scrutiny. However, evaluation of the effectiveness of herbal medicines can be challenging, as their active components are often not known. Accordingly, it may be difficult to ensure that an herbal preparation used in clinical trials contains the components underlying its purported therapeutic effect. We reasoned that the identification of actions of herbal medicines at well-defined molecular targets and subsequent identification of chemical compounds underlying these molecular effects might serve as surrogate markers in the hypothesis-guided evaluation of their therapeutic efficacy. A research program was initiated to characterize in vitro molecular actions of a collection of 58 traditional Chinese drugs that are often used for the treatment of stroke. The results indicate that these drugs possess activity at disparate molecular targets in the signaling pathways involved in N-methyl-d-aspartate (NMDA) receptor-mediated neuronal injury and death. Each herbal drug contains diverse families of chemical compounds, where each family comprises structurally related members that act with low affinity at multiple molecular targets. The data appear to support the multicomponent, multitarget approach of traditional Chinese medicine. Glutamate release and excessive stimulation of NMDA receptors cause status epilepticus-induced neuronal death and are involved in epileptogenesis. Therefore, these results are also relevant to the development of antiepileptogenic and neuroprotective therapy for seizures. The combination of principles of modern molecular medicine with certain ideas of traditional empirical Chinese medicine may be beneficial in translational medicine in general.

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.

Multiple weak hits confuse complex systems: a transcriptional regulatory network as an example

Robust systems, like the molecular networks of living cells, are often resistant to single hits such as those caused by high-specificity drugs. Here we show that partial weakening of the Escherichia coli and Saccharomyces cerevisiae transcriptional regulatory networks at a small number (3-5) of selected nodes can have a greater impact than the complete elimination of a single selected node. In both cases, the targeted nodes have the greatest possible impact; still, the results suggest that in some cases broader specificity compounds or multitarget drug therapies may be more effective than individual high-affinity, high-specificity ones. Multiple but partial attacks mimic well a number of in vivo scenarios and may be useful in the efficient modification of other complex systems.

Antecedents to effective treatment of hypertension in Hispanic populations

Hypertension is a common medical disorder affecting >50 million people. It is a primary modifiable risk factor to cardiovascular disease and a leading cause of death in black and Hispanic groups. This article focuses on patient-specific and physician-specific barriers that contribute to underdiagnosis, undertreatment, access issues, and poor adherence to therapy. Two cross-cultural interviewing frameworks, ETHNIC and ADHERE, are discussed as approaches that complement the traditional clinical assessment and treatment of hypertension in Hispanics.