Pharm

• -Drugs that accelerate the rate of urine formation
• -Result: removal of sodium and water

• -Where sodium goes, water follows- 20% to 25% of all sodium is reabsorbed into the bloodstream in the loop of henle, 5%to 10% in the distal tubules, 3% in collecting ducts
• -If water is not absorbed, it is excreted as urine

• -Carbonic anhydrase inhibitors
• -Loop diuretics
• -Osmotic diuretics
• -Potassium-sparing diuretics
• -Thiazide and thiazide-like diuretics

-acetazolamide (Diamox)

• -The enzyme carbonic anhydrase helps to make H+ ions available for exchange with sodium and water in the proximal tubules
• -CAIs block the action of carbonic anyhydrase, thus preventing the exchange of H+ ions with sodium and water
• -Inhibition of carbonic anhydrase reduces H+ ion concentration in renal tubules
• -As a result, there is increased excretion of bicarbonate, sodium, water and potassium
• -Resorption of water is decreased and urine volume is increased

• -Adjunct agents in the long-term management of open-angle glaucoma
• -Used with miotics to lower intraocular pressure before ocular surgery in certain cases
• -Also useful in the treatment of- Glaucoma, Edema, Epilepsy, High-altitude sickness
• -Acetazolamide is used in the management of edema secondary to HF when other diuretics are not effective
• -CAIs are less potent diuretics than loop diuretics or thiazides-the metabolic acidosis they induce reduces their diuretic effect in 2 to 4 days.

• -Metabolic acidosis -Paresthesias
• -Anorexia -Urticaria
• -Hematuria -Melena
• -Photosensitivity
• -Drowsiness

• -furisemide (Lasix)
• -bumetanide (Bumex)
• -ethacrynic acid (Edecrin)

• -Act directly on the ascending limb of the loop of Henle to inhibit sodium and chloride resorption
• -Increase renal prostaglandins, resulting in the dilation of blood vessels and reduced peripheral vascular resistance

• -Potent diuresis and subsequent loss of fluid
• -Decreased fluid volume causes- Reduced BP, reduced pulmonary vascular resistance, reduced systemic vascular resistance, reduced central venous pressure, reduced left ventricular end-disastolic pressure
• -Potassium depletion

• -Edema associated with HF or hepatic or renal disease
• -Control of hypertension
• -Increase renal excretion of calcium in patients with hypercalcemia

Body system -Effect

• CNS - Dizziness, headache, tinnitus, blurred vision
• GI- Nausea, vomiting, diarrhea
• Hematologic- Agranulocytosis, neutropenia, thrombocytopenia
• Metabolic- Hypokalemia, hyperglycemia, hyperuricemia

• -Electrolytes
• -Volume status
• -BUN/SCr

-mannitol (Osmitrol)

• -Work in the proximal tubule
• -Nonabsorabable, producing an osmotic effect
• -Pull water into the blood vessels and nephrons from the surrounding tissues

• -Reduced cellular edema
• -Increased urine production, causing diuresis
• -Rapid excretion of water, sodium, and other electrolyes, as well as excretion of toxic substances from the kidney
• -Reduced excessive intraocular pressure

• -Used in the treatment of patients in the early, oliguric phase of ARF
• -To promote the excretion of toxic substances
• -Reduction of intracranial pressure
• -Treatment of cerebral edema

• -Convulsions
• -Thrombophlebitis
• -Pulmonary congestion
• -Also headache, chest pain, tachycardia, blurred vision, chills, and fever

• -amiloride (Midamor)
• -triamterene (Dyrenium)
• -spironolactone (aldactone)
• -eplerenone (Inspra)

• -Work in collecting ducts and distal convoluted tubules
• -Intefere with sodium-potassium exchange
• -Competitively bind to aldosterone receptors
• -Block the resorption of sodium and water usually induced by aldosterone

• -Prevent potassium from being pumped into the tubule, thus preventing its secretion
• -Competitively block the aldosterone receptors and inhibit its action
• -The excretion of sodium and water is promoted

• -spironolactone and triamterene-Hyperaldosteronism, hypertension, reversing the potassium loss caused by potassium-losing drugs
• -amiloride- treatment of HF

-spironolactone- gynecomastia, amenorrhea, irregular menses, postmenopausal bleeding

-eplenerone- less gynecomastia, expensive

• -Thiazide diurectics- hydrochlorothiazide (Esidrix, HydroDIURIL), chlorothiazide (Diuril), trichloromethiazide (Metahydrin)
• -Thiazide-like diuretics- chlorthalidone (Hygroton), metolazone (Mykrox, Zaroxolyn)

• -Inhibit tubular resorption of sodium and chloride ions
• -Action primarily in the ascendnig loop of Henle and early distal tubule
• -Result: water, sodium, and chloride are excredted
• -Potassium is also excreted to a lesser extent
• -Dilate the arterioles by direct relaxation

• -Lowered peripheral vascular resistance
• -Depletion of sodium and water

• Hypertension ( one of the most prescribed group of agents for this)
• -Edematous states
• -Idiopathic hypercalciuria
• -Diabetes insipidus
• -adjunct agents in treatment of HF, hepatic cirrhosis

• Body system - Effect
• -CNS- dizziness, headache, blurred vision, paresthesias, decreased libido
• -GI- Anorexia, nausea, vomiting, diarrhea
• -GU- Impotence
• -Inegumentary- Urticaria, photosensitivity
• -Metabolic- Hypokalemia, glycosuria, hyperglycemia

• -Monitoring: - Electrolyes, BUN/SCr
• -Advantages: -Safe, cheap, daily dosing, less side effects

• -Perform a thorough patient history and physical examination
• -Asses baseline fluid volume status, intake and output, serum electrolyte values, weight, and vital signs-especially postural BPs
• -Assess for disorders that may contraindicate or necessitate cautious use of these agents
• -Instruct patients to take in the morning as much as possible to avoid interference with sleep patterns
• -Monitor serum potassium levels during therapy
• -Potassium supplements are usually not recommended when potassium levels exceed #mEq/L
• -Teach patient to mantain proper nutrional and fluid volume status
• -Teac patients to eat more potassium-rich foods when takin any but the potassium-sparing agents
• -Foods high in potassium include bananas, oranges, dates, raisins, plums, fresh vegetables, potatoes, meat, and fish
• -Patients taking diuretics alone with a digitalis preparation should be taught to monitor for digitalis toxicity
• -Diabetic patients who are taking thiazide and/ or loop diuretics should be told to monitor blood glucose and watch for elevated levels
• -Teach patients to change positions slowly, and to rise slowly after sitting or lying to prevent dizziness and possible fainting related to orthostatic hypotension
• -Encourage patients to keep a log of their daily weight
• -Encourage patients to return for follow-up visits and lab work
• -Patients who have been ill with nausea, vomiting, and/or diarrhea should notify their physician because fluid loss may be dangerous
• -Signs and symptoms of hypokalemia include muscle weakness, constipation, irregular pulse rate, and overall feeling of lethargy
• -Instruct patients to notify physician immediately if they experience rapid heart rates or syncope ( reflects hypotension or fluid loss)
• -A weight gain of 2 or more lbs a day or 5 or more lbs in a week should be reported immediately
• -Excessive consumption of licorice can lead to an additive hyppokalemia in patients taking thiazides
• -Monitor for adverse side effects: Metabolic alkalosis, drowsiness, lethargy, hypokalemia, tachycardia, hypotension, leg cramps, restlessness, decreased mental alertness
• -Monitor for theraputic effects- Reduction in edema, fluid volume overload, HF, reduction of hypertension, return to norma intraocular pressure