Can the renin-angiotensin system protect against stroke? A focus on angiotensin II receptor blockers

From a patient's perspective, stroke is the most devastating form of cardiovascular disease, representing the number one cause of permanent disability in the United States. Treatment of hypertension significantly reduces the risk of stroke; however, it is unclear whether all antihypertensive agents are equivalent in this regard. Angiotensin-converting enzyme (ACE) inhibitors have been shown to reduce the risk of cardiovascular events, including stroke. Although attenuation of the renin-angiotensin system (RAS) is often credited with the blood pressure-independent effects of this class of agents, this hypothesis has not been confirmed with regard to the end point of stroke. In fact, drugs that activate the RAS, such as diuretics and dihydropyridine calcium channel blockers, are as effective or superior to ACE inhibitors for stroke prevention. Angiotensin II receptor blockers (ARBs) selectively block the angiotensin II subtype I receptor, which results in a reflexive increase in levels of angiotensin II and unopposed activation of angiotensin II subtype 2 receptors. Clinical trials comparing ARBs with active controls have reported significant reductions in stroke in ARB-treated patients. Data on ARBs and other drugs that activate the RAS (diuretics and dihydropyridine calcium channel blockers) support a potential role for the RAS in protecting against stroke. Ongoing trials with ARBs are evaluating stroke as a primary end point, and results should help to further elucidate the role of ARBs in this disease. Until then, it is prudent to treat hypertension with an agent or combination of agents that are likely to result in a rapid and sustained reduction in blood pressure, taking into consideration patient characteristics, comorbidities, tolerability, and cost.     

Angiotensin II-receptor blockers: clinical relevance and therapeutic role.

The limitations of angiotensin-converting-enzyme (ACE) inhibitors and the role of angiotensin II-receptor blockers (ARBs) in the treatment of hypertension, heart failure, and diabetic nephropathy are discussed. Although ACE inhibitors are generally well tolerated, two important class-related adverse effects are cough, which is common, and angioedema, which is rare but serious. Cough and angioedema appear to be less frequent with ARBs than with ACE inhibitors. ARBs seem to be as capable as ACE inhibitors of producing renal dysfunction. ARBs may offer more complete inhibition of angiotensin II than ACE inhibitors. The mechanism of action is based on selective binding to angiotensin type 1 receptors. Many clinical studies have shown that ARBs lower blood pressure as effectively as other antihypertensive agents, including ACE inhibitors. ARBs do not appear to have a greater clinical effect than ACE inhibitors in patients with heart failure. Some studies of combination ARB and ACE inhibitor therapy for heart failure indicate advantages of the combination over therapy with either class. ARBs may exert renal protective effects in diabetic nephropathy. ARBs offer an alternative to ACE inhibitors in the management of hypertension, especially for ACE-inhibitor-intolerant patients. ACE inhibitors remain the drugs of choice for patients with heart failure, left ventricular dysfunction after MI, and diabetic nephropathy; ARBs offer these patients an alternative when ACE inhibitor therapy is not tolerated.     

The role of angiotensin II type 1 receptor antagonists in elderly patients with hypertension

Hypertension is a major risk factor for stroke and coronary events in elderly people and clinical trials have shown that treatment of hypertension with various drugs can result in a substantial reduction in cerebrovascular and cardiovascular events. The angiotensin II type 1 (AT1) receptor antagonists are the newest class of antihypertensive agents to be used widely in clinical practice. AT1 receptor antagonists can generally be given once-daily. They are also extremely well tolerated with minimal first-dose hypotension and an incidence of adverse effects similar to that seen with placebo. Adverse event rates are significantly lower than with other classes of antihypertensive drugs including ACE inhibitors. These factors result in improved compliance and increased rates of continuance on therapy. AT1 receptor antagonists show similar efficacy in lowering blood pressure to other classes of antihypertensive agents and their antihypertensive effect is potentiated when they are given concomitantly with low-dose thiazide diuretics. AT1 receptor antagonists are eliminated predominantly by the hepatic route but most are not subject to extensive metabolism and interactions with other drugs are uncommon. This is an advantage in the elderly, who are often receiving multiple medications which increases the risk for adverse drug interactions. Dose adjustments are not usually required in the elderly unless there is plasma volume depletion. Although plasma AT1 receptor antagonist concentrations are generally higher in the elderly than in younger subjects, this pharmacokinetic difference may be balanced by decreased activation of the circulating renin-angiotensin-aldosterone system in the elderly. Recent clinical studies in high-risk hypertensive patients with left ventricular hypertrophy or in patients with diabetic nephropathy or heart failure have demonstrated that AT1 receptor antagonists can improve clinical outcomes to a similar or sometimes greater extent than other antihypertensive agents. Many of these studies have included large numbers of older patients and have confirmed the excellent tolerability profile of these drugs. Thus, AT1 receptor antagonists should be considered as a possible first-line treatment or as a component of combination therapy in patients with type 2 diabetes mellitus and microalbuminuria or nephropathy and as an alternative or additional treatment to ACE inhibitors in patients with heart failure or left ventricular dysfunction. AT1 receptor antagonists also appear to reduce the onset of new diabetes compared with some other antihypertensive drugs. The benefits in terms of organ protection have mainly been seen in studies using higher doses of particular AT1 receptor antagonists and it is not certain at present whether these results can be extrapolated to other members of the class. As the elderly are more likely to have developed organ damage related to hypertension or to have heart failure or diabetes as concomitant conditions, AT1 receptor antagonists represent an appropriate option for many elderly patients. The main disadvantage of these drugs is the cost of the medication but this may be offset by their improved tolerability with fewer adverse reactions and thus increased compliance, resulting in better blood pressure control and fewer clinical events. Overall, AT1 receptor antagonists are well tolerated and efficacious for blood pressure-lowering when given as a single daily dose in elderly patients and have many potential benefits in high-risk hypertensive subjects.     

Clinical relevance of cimetidine drug interactions.

The excellent efficacy and tolerability profiles of H2-antagonists have established these agents as the leading class of antiulcer drugs. Attention has been focused on drug interactions with H2-antagonists as a means of product differentiation and because many patients are receiving multiple drug therapy. The main mechanism of most drug interactions involving cimetidine appears to be inhibition of the hepatic microsomal enzyme cytochrome P450, an effect which may be related to the different structures of H2-antagonists. Ranitidine appears to have less affinity than cimetidine for this system. There have been many published case reports and studies of drug interactions with cimetidine, but many of these have provided pharmacokinetic data only, with little information concerning the clinical significance of these findings. Nevertheless, the coadministration of cimetidine with drugs that have a narrow therapeutic margin (such as theophylline) may potentially result in clinically significant adverse effects. The monitoring of serum concentrations of drugs coadministered with cimetidine may reduce the risk of adverse events but does not abolish the problem. However, for most patients, concomitant administration of cimetidine with drugs possessing a wide therapeutic margin is unlikely to pose a significant problem.     

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in women of childbearing age: risks versus benefits

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are effective and widely used antihypertensive drugs. Exposure to these agents is known to be harmful to the fetus in the second and third trimesters of pregnancy. Concerns have also been raised about the risk of congenital malformations if ACEIs or ARBs are taken during the first trimester of pregnancy. The evidence to date, however, is conflicting and observed malformations may be due to confounders such as undiagnosed diabetes or maternal obesity, other antihypertensive medications or the hypertension itself. Nonetheless, in women who become pregnant while taking an ACEI or ARB, the drug should be stopped as soon as possible. In women with chronic kidney disease and proteinuria, it may be appropriate to continue taking an ACEI or ARB until the pregnancy is confirmed because of the significant benefit to their kidney function and the lower fertility rate in these patients.     

Comparison of Hyperkalemic Risk in Hospitalized Patients Treated with Different Angiotensin Receptor Blockers

Background and Aim

Clinical use of angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) is associated with hyperkalemia as an adverse drug reaction. Although it has significant clinical implications, the incidence and relative risks of hyperkalemia with various ARBs have not yet been fully evaluated. The purpose of this study was to determine the risk of hyperkalemic events in hospitalized patients treated with different ARBs and to compare the risk among them.

Methods

We constructed a retrospective cohort composed of hospitalized adult patients who took ARBs in a single tertiary teaching hospital between April 2004 and March 2010. We estimated the incidence of hyperkalemia (serum potassium level >5.5 mEq/L) with various ARBs, and then compared the risk between them using a multivariate Cox proportional hazard model based on age, sex, Charlson co-morbidity score, baseline serum potassium, underlying diseases, and concomitant drugs.

Results

We identified 6992 evaluable intervals from 5449 patients treated with one of the seven ARBs during hospitalization over the 71-month study period with 2521.6 patient-months. We found 381 hyperkalemic events (5.4%) during the study period and an overall event rate of 15.1/100 patient-months. Moderate to fatal hyperkalemia was relatively rare (>6.0 mEq/L, 2.1% [moderate]; >6.5 mEq/L, 0.9% [severe]; >7.0 mEq/L, 0.3% [fatal]). After adjustment for covariates, telmisartan showed a lower risk of hyperkalemia (hazard ratio 0.67; 95% confidence interval 0.51, 0.89) compared with all other ARBs.

Conclusion

The risk of hyperkalemic events in hospitalized patients treated with different ARBs was defined. Telmisartan showed a relatively lower hyperkalemic risk profile in hospitalized patients compared with other ARBs.     

Clinically significant drug interactions with antidepressants in the elderly

Pharmacological treatment of depression in old age is associated with an increased risk of adverse pharmacokinetic and pharmacodynamic drug interactions. Elderly patients may have multiple disease states and, therefore, may require a variety of other drugs. In addition to polypharmacy, other factors such as age-related physiological changes, diseases, genetic constitution and diet may alter drug response and, therefore, predispose elderly patients to adverse effects and drug interactions. Antidepressant drugs currently available differ in their potential for drug interactions. In general, older compounds, such as tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs), have a higher potential for interactions than newer compounds, such as selective serotonin reuptake inhibitors (SSRIs) and other relatively novel agents with a more specific mechanism of action. In particular, TCAs and MAOIs are associated with clinically significant pharmacodynamic interactions with many medications frequently prescribed to elderly patients. Moreover, TCAs may be susceptible to pharmacokinetic interactions when given in combination with inhibitors or inducers of the cytochrome P450 (CYP) isoenzymes involved in their metabolism. Because of a more selective mechanism of action, newer antidepressants have a low potential for pharmacodynamic drug interactions. However, the possibility of the serotonin syndrome should be taken into account when drugs affecting serotonergic transmission, such as SSRIs, venlafaxine or nefazodone, are coadministered with other serotonergic agents. Newer agents have a differential potential for pharmacokinetic interactions because of their selective effects on CYP isoenzymes. Within the group of SSRIs, fluoxetine and paroxetine are potent inhibitors of CYP2D6, while fluvoxamine predominantly affects CYP1A2 and CYP2C19 activity. Therefore, these agents should be closely monitored or avoided in elderly patients treated with substrates of these isoforms, especially those with a narrow therapeutic index. On the other hand, citalopram and sertraline have a low inhibitory activity on different drug metabolising enzymes and appear particularly suitable in an elderly population. Among other newer antidepressants, nefazodone is a potent inhibitor of CYP3A4 and its combination with substrates of this isoform should be avoided.     

Antihypertensive therapy: special focus on drug interactions

Today, the lifetime risk of patients aged 55-65 years to receive antihypertensive drugs approaches 60%. Yet, recent trials suggest that hypertension is not adequately controlled in the majority of patients. The prevalence of hypertension increases with advancing age, as does the prevalence of comorbid conditions and the total number of medications taken. Multi-drug therapy, advancing age and comorbid conditions are also key risk factors for adverse drug reactions and drug interactions. In this review, the authors evaluate the most frequently used antihypertensive drugs (diuretics, beta-adrenergic blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin II receptor Type 1 blockers and alpha-adrenergic blockers) with special reference to pharmacodynamic and pharmacokinetic drug interactions. As the spectrum of drugs prescribed is constantly changing, safety yesterday does not imply safety today and safety today does not imply safety tomorrow. Furthermore, therapeutic efficacy should not be neglected over concerns regarding drug interactions. Many patients are at risk of clinically relevant drug interactions involving antihypertensive drugs but, presently, even more patients may be at risk of suffering from the consequences of their inadequately treated hypertension. In this respect, the authors discuss controversial viewpoints on the overall clinical relevance of drug interactions occurring at the level of cytochrome P450 metabolism.     

Angiotensin II receptor blockers for the treatment of hypertension

The rising incidence of stroke, congestive heart failure (CHF) and end stage renal disease (ESRD) has signalled a need to increase awareness, treatment and control of hypertension. There continues to be a need for effective antihypertensive medications since hypertension is a major precursor to various forms of cardiovascular disease. The renin-angiotensin (AT) aldosterone system (RAAS) is a key component to the development of hypertension and can be one target of drug therapy. Angotensin II (ATII) receptor blockers (ARBs) are the most recent class of agents available to treat hypertension, which work by by inhibiting ATII at the receptor level. Currently, national consensus guidelines recommend that ARBs should be reserved for hypertensive patients who cannot tolerate angiotensin converting enzyme (ACE) inhibitors (ACEIs). ARBs, however, are moving to the forefront of therapy with a promising role in the area of renoprotection and CHF. Recent trials such as the The Renoprotective Effect of the Angiotensin-Receptor Antagonist Irbesartan in Patients with Nephropathy Due to Type 2 Diabetes Trial (IDNT), the Effect of Irbesartan on the Development of Diabetic Nephropathy in Patients with Type 2 Diabetes (IRMA2), and The Effects of Losartan on Renal and Cardiovascular Outcomes in Patients with Type 2 Diabetes and Nephropathy (RENAAL) study have demonstrated the renoprotective effects of ARBs in patients with Type 2 diabetes. The Valsartan Heart Failure Trial (Val-HeFT) adds to the growing body of evidence that ARBs may improve morbidity and mortality in CHF patients. As a class, ARBs are well tolerated and have a lower incidence of cough and angioedema compared to ACEIs. This article reviews the differences among the ARBs, existing efficacy data in hypertension, and explores the role of ARBs in CHF and renal disease.     

Angiotensin II receptor blockers for the treatment of hypertension

The rising incidence of stroke, congestive heart failure (CHF) and end stage renal disease (ESRD) has signalled a need to increase awareness, treatment and control of hypertension. There continues to be a need for effective antihypertensive medications since hypertension is a major precursor to various forms of cardiovascular disease. The renin-angiotensin (AT) aldosterone system (RAAS) is a key component to the development of hypertension and can be one target of drug therapy. Angotensin II (ATII) receptor blockers (ARBs) are the most recent class of agents available to treat hypertension, which work by by inhibiting ATII at the receptor level. Currently, national consensus guidelines recommend that ARBs should be reserved for hypertensive patients who cannot tolerate angiotensin converting enzyme (ACE) inhibitors (ACEIs). ARBs, however, are moving to the forefront of therapy with a promising role in the area of renoprotection and CHF. Recent trials such as the The Renoprotective Effect of the Angiotensin-Receptor Antagonist Irbesartan in Patients with Nephropathy Due to Type 2 Diabetes Trial (IDNT), the Effect of Irbesartan on the Development of Diabetic Nephropathy in Patients with Type 2 Diabetes (IRMA2), and The Effects of Losartan on Renal and Cardiovascular Outcomes in Patients with Type 2 Diabetes and Nephropathy (RENAAL) study have demonstrated the renoprotective effects of ARBs in patients with Type 2 diabetes. The Valsartan Heart Failure Trial (Val-HeFT) adds to the growing body of evidence that ARBs may improve morbidity and mortality in CHF patients. As a class, ARBs are well tolerated and have a lower incidence of cough and angioedema compared to ACEIs. This article reviews the differences among the ARBs, existing efficacy data in hypertension, and explores the role of ARBs in CHF and renal disease.     

Antihypertensive therapy: special focus on drug interactions

Today, the lifetime risk of patients aged 55 – 65 years to receive antihypertensive drugs approaches 60%. Yet, recent trials suggest that hypertension is not adequately controlled in the majority of patients. The prevalence of hypertension increases with advancing age, as does the prevalence of comorbid conditions and the total number of medications taken. Multi-drug therapy, advancing age and comorbid conditions are also key risk factors for adverse drug reactions and drug interactions. In this review, the authors evaluate the most frequently used antihypertensive drugs (diuretics, β-adrenergic blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin II receptor Type 1 blockers and α-adrenergic blockers) with special reference to pharmacodynamic and pharmacokinetic drug interactions. As the spectrum of drugs prescribed is constantly changing, safety yesterday does not imply safety today and safety today does not imply safety tomorrow. Furthermore, therapeutic efficacy should not be neglected over concerns regarding drug interactions. Many patients are at risk of clinically relevant drug interactions involving antihypertensive drugs but, presently, even more patients may be at risk of suffering from the consequences of their inadequately treated hypertension. In this respect, the authors discuss controversial viewpoints on the overall clinical relevance of drug interactions occurring at the level of cytochrome P450 metabolism.     

RISK-BENEFITS OF ANTIHYPERTENSIVE DRUGS - β-BLOCKERS

1. Beta-Blockers are of similar efficacy in the treatment of hypertension to other antihypertensive drugs of first choice; they have a wide spectrum of activity both alone and in combination. 2. Although beta-blockers first appear to worsen the haemodynamic changes of hypertension, subsequently peripheral resistance falls. The cardiovascular reflexes responsible for the responses of posture or other responses requiring normal functioning of alpha-mediated tone are not inhibited. 3. Important contra-indications are asthma and heart failure in susceptible subjects. Lipid soluble drugs have somewhat greater CNS side effects. 4. Triglyceride levels, notably an increase in VLDL and a fall in HDL occur from non-selective agents (less so from beta 1-selective agents) and there is a marginal effect from drugs with relatively high ISA. 5. In contrast to other antihypertensive drugs beta-blockers reduce the myocardial infarction rate in high risk patients (i.e. post-myocardial infarct). Results in primary prevention of mild hypertension have been less promising. 6. Those drugs which are lipid soluble and liver metabolized result in greater variation of plasma concentration after oral administration and some pharmacokinetic drug interactions. Once daily administration is possible with many beta-blockers. 7. beta-Blocking drugs have an established and proven place in the treatment of hypertension.     

The expanding role of angiotensin receptor blockers in the management of the elderly hypertensive

The world faces the challenge of an ageing population, and for developed countries, the particular challenge is the increasing number of very old people, over 80 years of age. Hypertension is a condition associated with increasing age, but elderly patients with hypertension are often difficult to manage. Nevertheless, treatment of hypertension is of greatest value in older patients who often have additional risk factors or cardiovascular disease. Older patients have generally tolerated antihypertensive therapy well in randomised, placebo-controlled trials. The tolerability of angiotensin receptor blockers (ARBs) is better than that of many other classes of drugs currently used for the management of hypertension and these drugs have virtually no contraindications. Thus, ARBs have a bright future in the management of hypertension and in the treatment of stroke and cognitive decline in the elderly.     

肾移植术后高血压的药物治疗

目的：介绍肾移植术后高血压药物治疗的具体方法和治疗中需要注意的问题。方法：对肾移植术后高血压的病因学进行了分析，结合目前常用的各类别抗高血压药物的作用特点，针对移植后高血压的特殊病因和肾移植病人特殊的病理生理状况，提出肾移植术后高血压药物治疗的具体策略。结果：治疗中需要了解不同抗高血压药物的作用特点，并考虑其对移植物可能造成的不利影响。还要考虑这些药物与免疫抑制药物之间的潜在药物相互作用，对于肾移植术后的其他并发症，如糖尿病、高胆固醇血症、胰岛素耐受、缺血性心脏病等影响也必须加以考虑。结论：高血压是肾移植病人移植物功能衰竭、心血管发病和死亡的重要危险因素，需要针对不同病因和情况合理使用抗高血压药物。     

Non-steroidal anti-inflammatory drugs (NSAIDs) and hypertension treatment intensification: a population-based cohort study

Purpose

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to antagonize the effects of antihypertensive drugs, and these associations can lead to an increase in arterial blood pressure. However, the impact of NSAIDs on hypertension treatment management in large-scale populations remains poorly evaluated. We examined whether the introduction of NSAID into the treatment regimen would induce an intensification of hypertension treatment (defined as the introduction of a new antihypertensive drug).

Methods

We conducted a cohort study involving 5,710 hypertensive subjects included in the French health insurance system database who had been treated and stabilized with their antihypertensive therapy and not exposed to any NSAID between 1 April 2005 and 1 April 2006. The maximum follow-up duration was 4?years.

Results

Adjusted hazard ratios (HR) for hypertension treatment intensification were 1.34 [95?% confidence interval (CI) 1.05–1.71] for NSAIDs in general, 1.79 (95?% CI 1.15–2.78) for diclofenac and 2.02 (95?% CI:1.09–3.77) for piroxicam. There were significant interactions between NSAIDs and angiotensin converting enzyme inhibitors (ACEIs; HR? 4.09, 95?% CI 2.02–8.27) or angiotensin receptor blockers (ARBs; HR?3.62, 95?% CI 1.80–7.31), but not with other antihypertensive drugs.

Conclusions

Exposure to NSAIDs leads to an intensification of hypertension treatment, especially in patients treated with ACEIs or ARBs. Renin–angiotensin system blockers should be avoided whenever NSAIDs are prescribed.     

Optimizing the Pharmacologic Treatment of Hypertension

Hypertension is a well documented risk factor for cardiovascular disease (CVD) and substantially contributes to the global burden of disease. Different drug options exist for combination therapy as part of an overall control of risk factors in order to decrease the absolute risk of CVD. Several guidelines in recent years have tried to set up recommendations to increase the proportion of subjects in acceptable BP control from high-risk groups. Some conventional drugs are still very important in modern hypertension treatment, e.g. low-dose thiazide diuretics. However, newer compounds have added to the list of useful agents to be used as monotherapy or in combination therapy for improved target organ protection, e.g. the calcium channel antagonists and ACE inhibitors. The role of β-adrenoceptor antagonists (β-blockers) has changed somewhat as a result of critical comments from recent meta-analyses. Currently, therefore, β-blockers are recommended less often for primary prevention and monotherapy, but should still be used for secondary prevention, combination therapy, and for symptom relief. Finally, the new angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) are still rather expensive, but have been increasingly documented in clinical trials for patients with essential hypertension. One controversial aspect is whether ARBs are better, worse, or equal to standard therapy with an ACE inhibitor for cardiovascular protection. BP remains poorly controlled in a large number of hypertensive patients and there is a greater need to control all relevant CVD risk factors in such patients. Therefore, different drugs are needed in order to be used in evidence-based synergistic and cost-effective drug combinations.     

The Role of Angiotensin Receptor Blocker and Calcium Channel Blocker Combination Therapy in Treating Hypertension

Hypertension remains a significant health problem, affecting approximately 30% of the US population. Of these, only 36.8% have BP controlled to recommended levels of <140/90mmHg for uncomplicated hypertension and <130/80 mmHg for patients with diabetes mellitus or renal disease. For those with uncontrolled hypertension, the risk of diabetes, renal disease, stroke, and cardiovascular disease is increased. Therapeutic options for the treatment of hypertension include several major classes of drugs: diuretics, ß-adrenoceptor antagonists (ß-blockers), ACE inhibitors, angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]), renin inhibitors, calcium channel blockers, and central sympatholytics, alone or in combination. Guidelines recommend thiazide diuretics as preferred first-line monotherapy. However, only 50% of patients will respond adequately to this therapy and the rest will require two or more antihypertensive agents to achieve BP goals. Clinical evidence demonstrates that some drugs have advantages when used in combination rather than as monotherapy. Drugs that block the renin-angiotensin-aldosterone system not only provide BP control but may also provide vascular protection and are metabolically neutral. This is a concise review of the safety and efficacy of ARBs in combination with amlodipine for the treatment of hypertension, with focus on the telmisartan-amlodipine combination. A MEDLINE search of the English literature from 2006 to 2009 of amlodipine in combination with ARBs revealed six publications, which are included in this review.     

The expanding role of angiotensin receptor blockers in the management of the elderly hypertensive

SUMMARY

The world faces the challenge of an ageing population, and for developed countries, the particular challenge is the increasing number of very old people, over 80 years of age. Hypertension is a condition associated with increasing age, but elderly patients with hypertension are often difficult to manage. Nevertheless, treatment of hypertension is of greatest value in older patients who often have additional risk factors or cardiovascular disease. Older patients have generally tolerated antihypertensive therapy well in randomised, placebo-controlled trials. The tolerability of angiotensin receptor blockers (ARBs) is better than that of many other classes of drugs currently used for the management of hypertension and these drugs have virtually no contraindications. Thus, ARBs have a bright future in the management of hypertension and in the treatment of stroke and cognitive decline in the elderly.     

A practical guide to the management of hypertension in renal transplant recipients

Hypertension as well as hypotension can be harmful to a newly transplanted renal allograft. Elevated blood pressure is also a major risk factor for cardiovascular death, which is a frequent occurrence despite successful renal transplantation. Renal artery stenosis, immunosuppressive drugs, chronic rejection, retained native kidneys, and excessive extracellular fluid volume may all contribute to post-transplant hypertension. Antihypertensive agents are widely used in the management of post-transplant hypertension. Careful clinical judgement and knowledge of the pharmacology, pharmacodynamics, pharmacokinetics, adverse drug reaction profiles, potential contraindications, and drug-drug interactions of antihypertensive agents are important when therapy with antihypertensive drugs is initiated in renal transplant recipients. Since blood pressure elevation in any individual is determined by a large number of hormonal and neuronal systems, the effect of antihypertensive agents on the allograft should be considered a critical factor in the management of hypertension in renal transplant recipients. Most renal transplant recipients have other risk factors for premature cardiovascular death such as diabetes mellitus, hypercholesterolemia, insulin resistance, obesity, left ventricular hypertrophy and ischaemic heart disease. Initial antihypertensive therapy should be tailored individually according to the patient's risk factors. A realistic therapeutic goal for blood pressure management in the initial post-operative state is a systolic blood pressure <160 mm Hg and a diastolic blood pressure <90 mm Hg with lower pressure targets becoming applicable late post-transplantation.     

抗反转录病毒治疗及机会感染治疗中的药物相互作用

目前有30余种药物用于艾滋病毒感染治疗。3种及以上抗病毒药物联合应用显著提高了抗反转录病毒治疗的疗效,但也存在多种药物相互作用。同时,艾滋病患者常因机会感染接受治疗,而抗感染药物,尤其是抗结核、抗真菌药物的使用会使药物相互作用更加复杂。药物相互作用可能导致治疗疗效下降和(或)增加不良反应风险。本文主要介绍抗反转录病毒治疗和机会感染治疗中的重要药物相互作用以及与此有关的配伍禁忌和剂量调整。