Diuretics Flashcards
(29 cards)
Loop diuretics: Action
Action – these are the most potent diuretics available.
They inhibit Na+ and Cl- resorption in renal tubules by direct action on the ascending loop of Henle.
They also inhibit Na+, Cl- and water resorption in proximal tubule.
And they increase the concentrations of renal prostaglandins → dilation of blood vessels in the kidneys, lungs.
Loop Diuretics: Uses
Uses – Edema associated with HF, liver, and kidney disease; hypertension, hypercalcemia (often seen in CA patients).
Loop Diuretics: Side Effects
SE –
Volume depletion [esp in elderly],
orthostatic hypotension,
electrolyte disturbances (esp hypokalemia), tinnitus, transient deafness,
impaired glucose tolerance,
blood dyscrasia,
Steven-Johnson syndrome (awful skin problems which can lead to toxic epidermal necrolysis where your skin falls off). Neurotoxic (hearing loss is one sign) and nephrotoxic effects.
Loop Diuretics: Interactions
Interactions –
additive neurotoxic and nephrotoxic effects, increase serum uric acid, glucose, AST, ALT. Interacts with digoxin. Also, consistent NSAIDs use → less diuresis.
Loop Diuretics: Drugs
Drugs – furosemide [Lasix]** – related to sulfa drugs., po, IV. Also → loss of magnesium and calcium.
Bumetanide [bumex]
Ethacrynate [Edecrin]* – can cause irreversible ototoxicity
Torsemide [Demadex]*
Loop Diuretics: Nursing considerations
Nursing considerations – same as above plus: give IV slowly, over 4 minutes Fast administration can → transient tinnitus or deafness. Store in light resistant containers. These pts often need K+ supplements.
Thiazide Diuretics: Action
Action – sulfa drugs –
Inhibit tubular resorption of Na+ and Cl- ions in the ascending loop of Henle and distal tubule.
These are nowhere near as strong as the loop diuretics.
Thus, water, Na+, and Cl- are excreted. Also K+.
Also may increase GFR.
At first the decrease in blood volume decreases CO, but after a while, this stabilizes.
These drugs are most effective after 3-4 weeks of Tx.
Thiazide Diuretics: Uses
Uses – Hypertension (should be the first line, but aren’t?), edema, hypercalciuria, diabetes insipidus, HF, cirrhosis
Thiazide Diuretics: Side effects
SE – Orthostatic hypotension, hyponatremia, hypokalemia, glucose intolerance, GI, rash, HA, impotence, deceased libido.
Thiazide Diuretics: Interactions
Interactions – Digoxin (causes toxicity). Oral hypoglycemics – reduced effect – check BS.
Bile acid sequestrants – You need separate administration of these 2 classes.
Thiazide Diuretics: Drugs
Drugs – hydrochlorothiazide [HCTZ, Hydro-Diuiril, Esidrix]** -has diuretic ceiling effect at about 50 mg.
chlorothiazide [Diuril]
chlorthalidone [Hygroton]*
indapamide [Lozol]*
Thiazide Diuretics: Nursing Considerations
Nursing considerations – Check K+ and look for sxs of hypokalemia. Give K+ supplements. Check blood sugar. Weigh daily. Get up slowly. Give in AM. Check for sulfa allergy.
Potassium sparing diuretics: ACTION
Action – Na+ ion channel inhibitors have direct action on distal renal tubules - inhibits Na resorption → excretion of Na+ and water, and retention of K+.
Overall Mechanism of Action
- Work in collecting ducts and distal convoluted tubules.
- Interfere with sodium-potassium exchange.
- Competitively bind to aldosterone receptors
- Block the resorption of sodium and water usually induced by aldosterone.
Potassium sparing diuretics: USES
Uses – Hypertension; with other diuretics to prevent K+ loss.
Potassium sparing diuretics: SIDE EFFECTS
SE – hyperkalemia, anemia, dizziness, orthostatic hypotension, sore throat, dry mouth, N/V, irreg menses, kidney stones, impotence, hirsutism
Potassium sparing diuretics: INTERACTIONS
Interactions – increased Lithium toxicity. ACE inhibitors and K+ supplements can → hyperkalemia. Licorice (raises the BP).
Potassium sparing diuretics: NURSING CONSIDERATIONS
Nursing considerations – Check for S/S of hyperkalemia. Give with food or milk to ease GI stuff.
Potassium sparing diuretics: DRUGS
amiloride [Midamor]*
usu used with loop or thiazide diuretics for CHF
Triamterene [Dyrenium]**
Aldosterone Antagonists (Prevent aldosterone from binding with receptors) also K sparing.
spironolactone [Aldactone]** - used for ascites, used for kids with CHF,
Eplerenone [Inspra]
Osmotic Diuretics: ACTION
Action –
Increase the osmolality of the plasma, glomerular filtrate, and tubular fluid.
Pull fluid from extravascular spaces into vascular and then to tubules.
These are inert and resistant to extensive metabolism.
Osmotic Diuretics:Effects
Effects –
a. Reduced cellular edema.
b. Increased urine production.
c. Rapid excretion of water, Na+, other lytes, and toxic substances.
d. Reduces intraocular pressure.
Osmotic Diuretics: Uses
Uses – Increased ICP, cerebral edema, ARF, reduce toxin levels
Osmotic Diuretics: Side effects
SE – Convulsions, thrombophlebitis, pulmonary congestion, HA, chest pains, tachycardia, blurred vision, chills, fever, rhinitis
Osmotic Diuretics: Drugs
Drugs – mannitol [Osmitrol]** - IV only
glycerin - po
urea [Ureaphil]*
Osmotic Diuretics: Nursing considerations
Nursing considerations –
Check urine output hourly.
Crystallizes at low temperatures - redissolve by warming in hot-water bath and shake, then let come to room temp. IV infusion rate is very important!
