Used in Congestive Heart Failure

SYMPATHOMIMETICS MOST COMMONLY USED IN CONGESTIVE HEART FAILURE... 

Dopamine and dobutamine are sometimes used to stimulate the heart in cases of acute or severe heart failure (see Chapter 20). Dopamine and dobutamine exert a fairly specific positive inotropic effect, presumably through their ability to stimulate beta-1 receptors on the myocardium.60 Other beta-1 agonists (epinephrine, prenalterol, etc.) will also increase myocardial contractility, but most of these other beta-1 agonists will also increase heart rate or have other side effects that prevent their use in congestive heart failure. Dopamine and dobutamine are usually reserved for patients with advanced cases of congestive heart failure who do not respond to other positive inotropic drugs (e.g., digitalis).6,72... 

FIGURE 35.7 Fenoldopam, which causes vasodilation, is useful in congestive heart failure. 

In addition, a vasodilator in combination with an angiotensin-converting enzyme inhibitor has been used in congestive heart failure. The vasodilators may be classified as venodilators, arterial dilators, or balanced-type vasodilators. 

Sympathomimetics Most Commonly Used in Congestive Heart Failure... 

Parenteral 40, 80, 160 mg/mL for IV injection 80, 160, 320 mg/dL in 5% dextrose for IV infusion Angiotensin-Converting Enzyme Inhibitors Labeled for Use in Congestive Heart Failure Captopril (generic, Capoten)... 

Q9 What is the mechanism of action of loop diuretics and why may they be more useful in congestive heart failure than the thiazides ... 

Coenzyme QIO is a powerful antioxidant naturally occurring in the mitochondria of myocardium, and it is an electron carrier in the mitochondrial synthesis of ATP. Patients with heart failure have lower myocardial levels of coenzyme QIO, but supplementation has been demonstrated to have variable benefits in randomized controlled trials. One meta-analysis on the use in congestive heart failure showed improvements in stroke volume, ejection fraction, cardiac output, cardiac index, and end diastolic volume index. " Another antioxidant associated with beneficial effects in cardiac patients is lycopene, a natural constituent of tomatoes. Lycopene is the major carotenoid found in human serum, and epidemiological studies have indicated an effect of dietary supplementation in reducing heart disease. Few dietary interventions have been reported one study showed a mild but significant hypocholesterolemic effect, and another showed a significant reduction in LDL oxidation. " Animal studies show an antiatherogenic effect of DHEA, and a review of the clinical trials and studies on DHEA in males with coronary heart disease reported a favorable or neutral effect. Plasma levels of DHEA are decreased in patients with chronic heart failure in proportion to its severity. ... 

Flosequinan is a vasodilator. Vasodilators in combination with an angiotensin-converting enzyme (ACE) inhibitor have been used in congestive heart failure. The vasodilators may be classified as venodilators, arterial dilators, or balanced-type vasodilators (Table 26). The rationale for vasodilation in the management of CHF is based on the increased arteriolar vasotone that occurs. This initiates a vicious circle in which cardiac function is further depressed by an increase in afterload and in resistance to ejection. 

The drugs used in congestive heart failure are shown in Figure 13-1. 

A. Diuretics Diuretics are often used in congestive heart failure before digitalis and other drugs are considered. Furosemide is a very useful agent for immediate reduction of the pulmonary congestion and severe edema associated with acute congestive heart failure or severe chronic failure. Thiazides such as hydrochlorothiazide are often used in the management of mild... 

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Although they are extremely useful in congestive heart failure, captopril and the other ACE inhibitors have no positive inotropic effect on the heart. The answer is (B). 

The isothiocyanate (178) was converted to the isothiourea (179), but on treatment with ammonia the nitrile reacted to give a guanidine without replacement of the methylthio group. It was suggested that steric hindrance from the ortAo-chlorines was responsible for this unexpected reactivity. However, the crude salt (180) readily gave (181) when treated with ammonia in the presence of mercuric chloride. Hydrolysis then afforded biclodil (182) Scheme 5.42.) [231]. The compound has been examined as a vasodilator useful in congestive heart failure [232], but is also used to treat coccidiosis [233],... 

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