Antihypertensive therapy

Many patients receiving antihypertensive therapy commonly receive more than one drug, placing them at risk tor orthostatic hypotension. It it occurs, your patient may tall and be injured. So teach the following measures to follow while in the acute caretadlity and at home ... 

While the main goal of antihypertensive therapy is to achieve target blood pressures, the selection of agents for an individual should also account for certain special considerations and a patient s comorbidities. Specific antihypertensive therapy is warranted for certain patients with comorbid conditions that may elevate their level of risk for cardiovascular disease. 

Patients with asymptomatic left ventricular systolic dysfunction and hypertension should be treated with P-blockers and ACE inhibitors. Those with heart failure secondary to left ventricular dysfunction and hypertension should be treated with drugs proven to also reduce the morbidity and mortality of heart failure, including P-blockers, ACE inhibitors, ARBs, aldosterone antagonists, and diuretics for symptom control as well as antihypertensive effect. In African-Americans with heart failure and left ventricular systolic dysfunction, combination therapy with nitrates and hydralazine not only affords a morbidity and mortality benefit, but may also be useful as antihypertensive therapy if needed.66 The dihydropyridine calcium channel blockers amlodipine or felodipine may also be used in patients with heart failure and left ventricular systolic dysfunction for uncontrolled blood pressure, although they have no effect on heart failure morbidity and mortality in these patients.49 For patients with heart failure and preserved ejection fraction, antihypertensive therapies that should be considered include P-blockers, ACE inhibitors, ARBs, calcium channel blockers (including nondihydropyridine agents), diuretics, and others as needed to control blood pressure.2,49... 

The treatment of elderly patients with hypertension, as well as those with isolated systolic hypertension, should follow the same approach as with other populations with the exception that lower starting doses may be warranted to avoid symptoms and with special attention paid to postural hypotension. This should include a careful assessment of orthostatic symptoms, measurement of blood pressure in the upright position, and caution to avoid volume depletion and rapid titration of antihypertensive therapy.2 In individuals with isolated systolic hypertension, the optimal level of diastolic pressure is not known, and although treated patients who achieve diastolic pressures less than 60 to 70 mm Hg had poorer outcomes in a landmark trial, their cardiovascular event rate was still lower than those receiving placebo.69... 

Blood pressure of 130/85 mm Hg or greater or active treatment with antihypertensive therapy. 

Poor sleep architecture and fragmented sleep secondary to OSA can cause excessive daytime sleepiness (EDS) and neu-rocognitive deficits. These sequelae can affect quality of life and work performance and may be linked to occupational and motor vehicle accidents. OSA is also associated with systemic disease such as hypertension, heart failure, and stroke.21-23 OSA is likely an independent risk factor for the development of hypertension.24 Further, when hypertension is present, it is often resistant to antihypertensive therapy. Fatal and non-fatal cardiovascular events are two- to threefold higher in male patients with severe OSA.25 OSA is associated with or aggravates biomarkers for cardiovascular disease, including C-reactive protein and leptin.26,27 Patients with sleep apnea often are obese and maybe predisposed to weight gain. Hence, obesity may further contribute to cardiovascular disease in this patient population. 

ACE inhibitors and angiotensin-receptor blockers (ARB) have definite benefits in patients with nephropathy and are believed to have renoprotective effects in most patients. Due to their ability to cause an initial bump in serum creatinine, these agents should be used cautiously when employed in combination with the calcineurin inhibitors. The dihydropyridine calcium channel blockers have demonstrated an ability to reverse the nephrotoxicity associated with cyclosporine and tacrolimus (Table 52-8). In general, antihypertensive therapy should focus on agents with proven benefit in reducing the progression of cardiovascular disease and should be chosen on a patient-specific basis.55 See Chapter 2 for further recommendations for treating HTN. 

For women with 140 to 179 mm Hg systolic or 90 to 109 mm Hg diastolic, the decision to continue or stop antihypertensive therapy during pregnancy is controversial. Antihypertensive drugs may be continued during pregnancy except for ACEIs and angiotensin II receptor blockers. 

Antihypertensive therapy should be initiated in diabetic or nondiabetic CKD patients with an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin II receptor blocker. Nondihydropyridine calcium channel blockers are generally used as second-line antiproteinuric drugs when ACEIs or angiotensin II receptor blockers are not tolerated. 

Because of their capability of lowering the blood pressure regardless of body position, of their overall excellent acceptance by the patients and because of their favorable hemodynamic effects, the diuretic agents remain the most important contribution to antihypertensive therapy. 

Chlorexolone is thus another effective oral diuretic which may also form the basis of antihypertensive therapy. While many cases appear adequately controlled on chlorexolone alone [336] more severely ill patients may require its potentiation with specific antihypertensive drugs. 

Dihydralazine and minoxidil (via its sulfate-conjugated metabolite) dilate arterioles and are used in antihypertensive therapy. They are, however, unsuitable for monotherapy because of compensatory circulatory reflexes. The mechanism of action of dihydralazine is unclear. Minoxidil probably activates K channels, leading to hyperpolarization of smooth muscle cells. Particular adverse reactions are lupus erythematosus with dihydralazine and hirsutism with minoxidil—used topically for the treatment of baldness (alopecia androg-enetica). 

Antihypertensive therapy. Diuretics have long been used as drugs of first choice for lowering elevated blood pressure (p. 312). Even at low dosage, they decrease peripheral resistance (without significantly reducing EEV) and thereby normalize blood pressure. 

Arterial hypertension (high blood pressure) generally does not impair the well-being of the affected individual however, in the long term it leads to vascular damage and secondary complications (A). The aim of antihypertensive therapy is to prevent the latter and, thus, to prolong life expectancy. 

A universally accepted principle of antihypertension therapy is the simultaneous use of several drugs that act on the primary regions controlling arterial blood pressure, and it is generally recommended to use a combination of diuretics, adrenoblockers, angiotensinconverting enzyme inhibitors, or calcium channel blockers. 

In antihypertension therapy, the most frequently used drugs are diltiazem (19.3.10), verapamil (19.3.15), and nifedipin (19.3.16), which appear to be equally effective drags for treating hypertension. Methods of syntheses have already been discussed in Chapter 19. 

Hypertension - Usual dose is 5 mg once daily. Maximum dose is 10 mg once daily. Small, fragile, or elderly patients or patients with hepatic insufficiency may be started on 2.5 mg once daily this dose may also be used when adding amlodipine to other antihypertensive therapy. In general, titrate over 7 to 14 days proceed more rapidly if clinically warranted with frequent assessment of the patient. 

For initial therapy, start with the 0.1 mg system. If, after 1 or 2 weeks, desired blood pressure reduction is not achieved, add another 0.1 mg system or use a larger system. Dosage greater than two 0.3 mg systems usually does not improve efficacy. Note that the antihypertensive effect of the system may not commence until 2 to 3 days after application. Therefore, when substituting the transdermal system in patients on prior antihypertensive therapy, a gradual reduction of prior drug dosage is advised. Previous antihypertensive treatment may have to be continued, particularly in patients with severe hypertension. 

Caution is advised when tizanidine is to be used in patients receiving concurrent antihypertensive therapy and should not be used with other 2adrenergic agonists. 

Hamet P, Gong L. Antihypertensive therapy debate contribution from the Shanghai Trial Of Nifedipine in the Elderly (STONE). J Hypertens Suppl 1996 14(4) S9-14. 

ALLHAT Authors/Officers and Coordinators. Diuretic versus alpha-blocker as first-step antihypertensive therapy final results from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). Hypertension 2003 42 239-46. 

III.c.6.2. Resistant hypertension. Hypertension should be considered resistant if the BP cannot be reduced to below 140/90 mmHg in patients who adhere to a triple-drug regimen that includes a diuretic, with all three drugs in near maximal doses. For older patients with isolated SBP, resistance is defined as failure of an adequate triple-drug regimen to reduce SBP below 160 mmHg. The various causes of true resistance are listed in Table 9. One of the most common causes is volume overload as a result of inadequate diuretic therapy. Patients who have resistant hypertension or who are unable to tolerate antihypertensive therapy may benefit from referral to a hypertension specialist. 

Table 8. General guidelines to improve patient adherence to antihypertensive therapy (Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure, 1997)...

Be aware of signs of patient non-adherence to antihypertensive therapy... 

Which of the following drugs is an appropriate initial antihypertensive therapy in an otherwise healthy adult with mild hypertension ... 

Most cases of secondary ED are related to arteriosclerosis. ED is also associated with hypertension, antihypertensive therapy, and diabetes meUitus, particularly in the older diabetic. Other chronic diseases, such as psychogenic disorders and Peyronie s disease, may be associated with ED. 

Kuperstein R. and Z. Sasson (2000). Effects of antihypertensive therapy on glucose and insulin metabolism and on left ventricular mass. Circulation 102 1802-1806. 

Blood pressure aggressively for an increase because 25% of patients taking darbe-poetin alfa require antihypertensive therapy and dietary restrictions... 

May increase by 2.5 mg/hr ql5min. After BP goal is achieved, decrease rate to 3 mg/hr. Rapid BP decrease. Initially, 5 mg/hr. May increase by 2.5 mg/hr q5min. Maximum 15 mg/hr until desired BP attained. After BP goal achieved, decrease rate to 3 mg/hr. Changing from IV to oral antihypertensive therapy Begin antihypertensives other... 

As noted earlier, lithium is contraindicated in patients with unstable congestive heart failure or the sick sinus node syndrome ( 307, 328). In older patients or those with prior cardiac histories, a pretreatment ECG should be obtained. Except for the potential adverse interactions with diuretics, the concomitant use of other cardiac drugs is generally safe. Because verapamil may lower serum levels of lithium, however, more careful monitoring may be required to assure continued therapeutic effects (329). Some data also indicate that verapamil may predispose to lithium neurotoxicity. Conversely, increased lithium levels leading to toxicity has occurred with methyidopa and enalapril. When antihypertensive therapy is necessary, b-blockers are a reasonable choice when lithium is coadministered. 

Should it occur, treatment is largely symptomatic chlorpromazine 50-100 mg may control the central excitatory symptoms, and contribute to control of others, while more specific antihypertensive therapy may be required labetalol, a combined a- and p-adrenoceptor antagonist, has been used successfully. Arrhythmias may require 3 blockade. 

The net cardiovascular effects of moderate doses of cholinesterase inhibitors therefore consist of modest bradycardia, a fall in cardiac output, and an increased vascular resistance that result in a rise in blood pressure. (Thus, in patients with Alzheimer s disease who have hypertension, treatment with cholinesterase inhibitors requires that blood pressure be monitored to adjust antihypertensive therapy.) At high (toxic) doses of cholinesterase inhibitors, marked bradycardia occurs, cardiac output decreases significantly, and hypotension supervenes. 

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