Diuretics adverse effects

Potassium-sparing by diuretic agents, particularly spironolactone, enhances the effectiveness of other diuretics because the secondary hyperaldosteronism is blocked. This class of diuretics decreases magnesium excretion, eg, amiloride can decrease renal excretion of potassium up to 80%. The most important and dangerous adverse effect of all potassium-sparing diuretics is hyperkalemia, which can be potentially fatal the incidence is about 0.5% (50). Therefore, blood potassium concentrations should be monitored carehiUy. 

Diuretics cause numerous adverse effects and metabolic abnormalities, with severity linked to diuretic potency. A particularly worrisome adverse effect in the setting of HF is... 

Patients at increased risk of NSAID-induced gastrointestinal adverse effects (e.g., dyspepsia, peptic ulcer formation, and bleeding) include the elderly, those with peptic ulcer disease, coagulopathy, and patients receiving high doses of concurrent corticosteroids. Nephrotoxicity is more common in the elderly, patients with creatinine clearance values less than 50 mL/minute, and those with volume depletion or on diuretic therapy. NSAIDs should be used with caution in patients with reduced cardiac output due to sodium retention and in patients receiving antihypertensives, warfarin, and lithium. 

Combination therapy with an ARB and ACE inhibitor offers a theoretical advantage over either agent alone through more complete blockade of the deleterious effects of angiotensin II. However, clinical trial results indicate that the addition of an ARB to optimal HF therapy (e.g., ACE inhibitors, /3-blockers, diuretics) offers marginal benefits at best with increased risk of adverse effects. Addition of an ARB may be considered in patients who remain symptomatic despite receiving optimal conventional therapy. 

Equipotent doses of loop diuretics (furosemide, bumetanide, torsemide, ethacrynic acid) have similar efficacy. Ethacrynic acid is reserved for sulfa-allergic patients. Continuous infusions of loop diuretics appear to be more effective and to have fewer adverse effects than intermittent boluses. An initial IV loading dose (equivalent to furosemide 40 to 80 mg) should be administered before starting a continuous infusion (equivalent to furosemide 10 to 20 mg/hour). 

Massive use of diuretics entails a hazard of adverse effects (A) (1) the decrease in blood volume can lead to hypotension and collapse (2) blood viscosity rises due to the increase in eryth-ro- and thrombocyte concentration, bringing an increased risk of intravascular coagulation or thrombosis. 

The diuretic effect of spironolactone develops fully only with continuous administration for several days. Two possible explanations are (1) the conversion of spironolactone into and accumulation of the more slowly eliminated metabolite canrenone (2) an inhibition of aldosterone-stimulated protein synthesis would become noticeable only if existing proteins had become nonfunctional and needed to be replaced by de novo synthesis. A particular adverse effect results from interference with gonadal hormones, as evidenced by the development of gynecomastia (enlargement of male breast). Clinical uses include conditions of increased aldosterone secretion, e.g., liver cirrhosis with ascites. 

Minoxidil may produce serious adverse effects. It can cause pericardial effusion, occasionally progressing to tamponade it can exacerbate angina pectoris. Reserve for hypertensive patients who do not respond adequately to maximum therapeutic doses of a diuretic and 2 other antihypertensive agents. 

ASA, NSAIDs, food EMS Monitor ECG for hypokalemia (peaked T waves), esp in pts taking K-sparing diuretics may affect glucose (hypoglycemia) concurrent EtOH use can t adverse effects may cause posistent cough OD May cause profound hypotension give IV fluids... 

Altered homeostasis in older persons can lead to important and common adverse drug effects the less robust homeostatic milieu may be stressed by drugs, causing adverse effects. Examples include orthostatic hypotension due to antihypertensives and other agents that cause a-adrenergic blockade (e.g. terazosin, doxazosin, tricyclic antidepressants and phenothiazines) in those with barorecep-tor dysfunction. Diuretics can cause hyponatraemia or hypokalaemia in older patients, whereas ACE inhibitors and NSAIDs can cause hyperkalaemia. 

Furosemide, torsemide, and bumetanide are sulfonamide derivatives, hence chemically related to the thiazides. They share the thiazides adverse effects of serum uric acid elevation and diabetogenic potential. Ethacrynic acid (Edecrin) is chemically unrelated to other diuretics and does not appear to have diabetogenic potential. 

It is indicated in all grades of essential hypertension and renovascular hypertension where standard therapy is ineffective or inappropriate because of adverse effects and in congestive heart failure. It should be used as an adjunctive therapy with digitalis and/or diuretics. 

Because CBZ can cause hyponatremia, it should be used cautiously in patients on a salt-restricted diet ( 373). Hyponatremia is rarely clinically significant when sodium values are above 125 mmol/L. Low sodium levels, as well as concomitant diuretic and lithium users, may predispose to the development of the syndrome of inappropriate ADH. Since CBZ enhances the effects of ADH, it can lead to impairment of free water clearance from the body. Older patients are at higher risk and should be closely monitored for this adverse effect which can be managed by dose reduction of CBZ. More severe cases, however, usually require switching to... 

---