Heart failure renal function

It is a quinazoline-derived nonthiazide diuretic. It is found to be more effective in comparison to the thiazide-like diuretics in the treatment of edema in such patients who have a histoiy of compromised renal function. It is extensively indicated for hypertension, edema accompanying congestive heart failure, renal disease including the nephrotic syndrome and other conditions of retarded renal function. 

Under certain circumstances, and very rarely, the inhibition of gluconeogenesis by metformin may suppress lactic acid metabolism and precipitate a potentially fatal lactic acidosis. Impairment of renal function, liver disease, alcoholism, conditions that give rise to increased lactate production (e.g. congestive heart failure, infections) are therefore contraindications for the application of metformin. 

The corticosteroids are administered with caution in older adults because they are more likely to have preexisting conditions such as congestive heart failure, hypertension, osteo-poros s and arthritis which may be worsened by the use of such agents The nurse monitors older adults for exacerbation of existing conditionsduring corticosteroid therapy. In addition, lower dosages may be needed because of the effects of aging, such as decreased muscle mass renal function, and plasma volume. 

The potent antidiuretic hormone AVP orchestrates the regulation of free water absorption, body fluid osmolality, cell contraction, blood volume, and blood pressure through stimulation of three G-protein-coupled receptor subtypes Vi-vascular types a and b, V2-renal, and V3-pituitary. Increased AVP secretion is the trademark of several pathophysiological disorders, including heart failure, impaired renal function, liver cirrhosis, and SIADH. As a consequence, these patients experience excess water retention or inadequate free-water excretion, which results in the dilution of sodium concentrations, frequently manifesting as clinical hyponatremia (serum sodium concentration <135mmol/L). This electrolyte imbalance increases mortality rates by 60-fold. Selective antagonism of the AVP V2 receptor promotes water... 

The answer is d. (Hardman, p 7502) The most consistent of the toxicides of ACT inhibitors is impairment of renal function, as evidenced by proteinuria. Elevations of blood urea nitrogen (BUN) and creatinine occur frequently, especially when stenosis of the renal artery or severe heart failure exists Hyperkalemia also may occur These drugs are to be used very cautiously where prior renal failure is present and in the elderly Other toxicides include persistent dry cough, neutropenia, and angioedema. Hepatic toxicity has not been reported... 

Angiotensin converting enzymes- inhibitors (ACE-inhibitors) are a group of drugs that are very potent in dilating the blood vessels and through this mechanism lower the blood pressure. Therefore they can also improve heart function in patients with heart failure. In some cases they are also used for preventing renal failure in persons with hypertension and/or diabetes. Paradoxically, this later use of ACE-inhibitors... 

Daily maintenance doses for each age group are given in the table below and should provide therapeutic effects with minimum risk of toxicity in most patients with heart failure and normal sinus rhythm. These recommendations assume the presence of normal renal function ... 

Silverberg DS, Wexler D, Blum M, et al. The use of subcutaneous erythropoietin and intravenous iron for the treatment of the anemia of severe, resistant congestive heart failure improves cardiac and renal function and functional cardiac class, and markedly reduces hospitalizations. J Am Coll Cardiol. Jun 2000 35(7) 1737-1744. 

Lithium intoxication can be precipitated by the use of diuretics, particularly thiazides and metola-zone, and ACE inhibitors. NSAIDs can also precipitate lithium toxicity, mainly due to NSAID inhibition of prostaglandin-dependent renal excretion mechanisms. NSAIDs also impair renal function and cause sodium and water retention, effects which can predispose to interactions. Many case reports describe the antagonistic effects of NSAIDs on diuretics and antihypertensive drugs. The combination of triamterene and indomethacin appears particularly hazardous as it may result in acute renal failure. NSAIDs may also interfere with the beneficial effects of diuretics and ACE inhibitors in heart failure. It is not unusual to see patients whose heart failure has deteriorated in spite of increased doses of frusemide who are also concurrently taking an NSAID. 

Hypotension, in particular in combination with diuretics, is a well-known adverse reaction to ACE-inhibitors when used in patients with heart failure. Dry cough, possibly mediated by the accumulation of bradykinin, is also a well-known side-effect in 5-15% of the patients treated with an ACE-inhibitor. Impaired renal function may be worsened by ACE-inhibitors. Allergic reactions, sometimes rather intense, may be observed occasionally. In rare cases angioneurotic edema has been described. ACE inhibitors should be avoided in women who are likely... 

Abnormal clearance may be anticipated when there is major impairment of the function of the kidney, liver, or heart. Creatinine clearance is a useful quantitative indicator of renal function. Conversely, drug clearance may be a useful indicator of the functional consequences of heart, kidney, or liver failure, often with greater precision than clinical findings or other laboratory tests. For example, when renal function is changing rapidly, estimation of the clearance of aminoglycoside antibiotics may be a more accurate indicator of glomerular filtration than serum creatinine. 

ACE inhibitors have a particularly useful role in treating patients with chronic kidney disease because they diminish proteinuria and stabilize renal function (even in the absence of lowering of blood pressure). This effect is particularly valuable in diabetes, and these drugs are now recommended in diabetes even in the absence of hypertension. These benefits probably result from improved intrarenal hemodynamics, with decreased glomerular efferent arteriolar resistance and a resulting reduction of intraglomerular capillary pressure. ACE inhibitors have also proved to be extremely useful in the treatment of heart failure, and after myocardial infarction, and there is recent evidence that ACE inhibitors reduce the incidence of diabetes in patients with high cardiovascular risk (see Chapter 13). 

Many glomerular diseases, such as those associated with diabetes mellitus or systemic lupus erythematosus, exhibit renal retention of salt and water. The cause of this sodium retention is not precisely known, but it probably involves disordered regulation of the renal microcirculation and tubular function through release of vasoconstrictors, prostaglandins, cytokines, and other mediators. When edema or hypertension develops in these patients, diuretic therapy can be very effective. If heart failure is also present, see the warnings mentioned above. 

Givertz MM et al The effects of KW-3902, an adenosine Al-receptor antagonist, on diuresis and renal function in patients with acute decompensated heart failure and renal impairment or diuretic resistance. 3 Am Coll Cardiol 2007 50(16) 1551. [PMID 17936154]... 

When given in larger than physiologic amounts, steroids such as cortisone and hydrocortisone, which have mineralocorticoid effects in addition to glucocorticoid effects, cause some sodium and fluid retention and loss of potassium. In patients with normal cardiovascular and renal function, this leads to a hypokalemic, hypochloremic alkalosis and eventually to a rise in blood pressure. In patients with hypoproteinemia, renal disease, or liver disease, edema may also occur. In patients with heart disease, even small degrees of sodium retention may lead to heart failure. These effects can be minimized by using synthetic non-salt-retaining steroids, sodium restriction, and judicious amounts of potassium supplements. 

Metformin Obscure Reduced hepatic and renal gluconeogenesis Decreased endogenous glucose production Type 2 diabetes Oral maximal plasma concentration in 2-3 h Toxicity Gastrointestinal symptoms, lactic acidosis (rare) cannot use if impaired renal/hepatic function congestive heart failure (CHF), hypoxic/acidotic states, alcoholism... 

In a double-blind placebo-controlled study of the effects of three doses of tolvaptan (30, 45, or 60 mg/day) in 254 patients with chronic heart failure taking stable doses of furosemide there were significant reductions in body weight and increased urine volumes edema improved and serum sodium normalized in those with hyponatremia (5). There were no significant changes in heart rate, blood pressure, serum potassium, or renal function. 

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