What is the mechanism of action for Diuretic Agents?
Kidney filters out toxic wastes while saving important chemicals.
The nephron (1,000,000 per kidney!) maintains this delicate balance
Drugs that accelerate the rate of urine formation.
Result: removal of sodium and water (and other electrolytes)
Diuretics
Name some Diuretic Agents.
Carbonic anhydrase inhibitors
Loop diuretics
Osmotic diuretics
Potassium-sparing diuretics
Thiazide and thiazide-like diuretics
What is the mechanism of action for Carbonic Anhydrase Inhibitors: acetazolamide (Diamox)?
The enzyme carbonic anhydrase helps to make H+ ions available for exchange with sodium and water in the proximal tubules.
Block the action of carbonic anhydrase, preventing the exchange of H+ ions w/ Na+ & H2O.
Inhibition of carbonic anhydrase reduces H+
What are Carbonic Anhydrase Inhibitors: Therapeutic Uses?
Adjunct agents in the long-term mgt of open-angle glaucoma
Used with miotics to lower intraocular pressure before ocular surgery in certain cases (when narrow-angle delayed)
Also useful in the treatment of:
Glaucoma, Edema of CHF, Epilepsy, High-altitude
Name some drugs and other Carbonic Anhydrase Inhibitors: Therapeutic Uses?
Acetazolamide is used in the management of edema secondary to CHF 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.
Carbonic Anhydrase Inhibitors: Side Effects? (Most common)
Metabolic abnormalities like Metabolic acidosis
What are Carbonic Anhydrase Inhibitors: Side Effects?
Drowsiness, Anorexia/ NV,Paresthesias, Hematuria,Urticaria,
Photosensitivity,Melena(darkening of stool),Rash, Blood dyscrasias
Name some Loop Diuretics.
bumetanide (Bumex), ethacrynic acid (Edecrin), furosemide (Lasix)
What is Loop Diuretic's Mechanism of action?
Act directly on the ascending limb of the loop of Henle to inhibit sodium and chloride resorption.(Keep Na and Cl)
Increase renal prostaglandins, resulting in the dilation(Increase blood flow) of blood vessels and reduced peripheral vascular resistance.
D
What are Loop Diuretics: Drug Effects?
Potent diuresis and subsequent loss of fluid
RAPID ONSET OF ACTION. Lasts at least 2 hours. Diuretic action works even when creatinine clearance <25mL/min. so still work when kidney fx decreased
Decreased fluid volume causes:
Reduced BP; Reduced pulmonary
What are Loop Diuretics:Therapeutic Uses?
Edema associated with CHF or hepatic or renal disease
Control of hypertension
What are some Loop Diuretics: Common Side Effects?
CNS:Dizziness, headache, tinnitus, blurred vision, Ototoxicity
GI: N/V,diarrhea
Hematologic:blood dyscrasias(Shifts in RBCS, get CBC), > lipids
Metabolic:Hypokalemia, hyponatremia,hypochloremia, hypomagnesemia, hypocalcemia, hyperglycemia,hyperuricemia, d
Name a Osmotic Diuretic and the mechanism of action?
Mannitol (Osmitrol)
Mechanism of Action: Work in the proximal tubule of kidney
Nonabsorbable, producing osmotic effect
Pull water into the blood vessels and nephrons from the surrounding tissues
> Blood volume causes excretion of water & electrolytes by t
What are the Osmotic Diuretics: Drug Effects?
Reduced cellular edema
> urine production, causing diuresis
Rapid excretion of water, sodium, and other electrolytes, as well as excretion of toxic substances from the kidney
Reduces excessive intraocular pressure by drawing water from the eye.
Reduced in
What are the Osmotic Diuretics: Therapeutic Uses?
Used in the treatment of patients in the early, oliguric phase of Acute Renal Failure
Promotes excretion of toxic substances
Reduction of intracranial pressure
Treatment of cerebral edema
Reduces intraocular pressure.
What are Osmotic Diuretics: Side Effects?
Convulsions
Thrombophlebitis
Pulmonary congestion & CHF from increased blood volume
If passes through capillary pores into tissues, edema results.Less significant: headaches, N/V, tachycardia, blurred vision, chills, and fever
How should you administer Osmotic Diuretics?What should you check the solution for? what type of needle should you use? When should you stop?
IV solutions available in several concentrations
Determine compatibility w/ IV fluids
Check solution for crystals. May warm to dissolve crystals, but then cool to body temp before administration.
Use filter needle & inline filter to prevent any crystals f
Name some Potassium-Sparing Diuretics and what's there mechanism of action?
Work in collecting ducts and distal convoluted tubules
Interfere with sodium-potassium exchange(Na leaves H20 follows and K comes in)
Competitively bind to aldosterone receptors
Block the resorption of sodium and water usually induced by aldosterone
What are some Potassium-Sparing Diuretics: Drug Effects?
Prevent K+ 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; potassium is retained
Relatively weak: rarely used alone
What are some Potassium-Sparing Diuretics: Therapeutic Uses?
Hyperaldosteronism
Hypertension
Reversing the potassium loss caused by potassium-losing drugs
What are Potassium-Sparing Diuretics: Side Effects?
CNS:Dizziness, headache
GI:Cramps, nausea, vomiting, diarrhea
Other:Urinary frequency,weakness **hyperkalemia
What are some Potassium-sparing diuretics: Side effects/adverse effects of Spironolactone (Aldactone)?
aldosterone antagonist can cause gynecomastia, irregular menses, amenorrhea, postmenopausal bleeding; hirsutism, deepening voice (endocrine D/Os)
What are some Potassium-sparing diuretics: Side effects/adverse effects of Triamterene (Dyrenium) & amilride (Midamor)?
nonaldosterone antagonists can cause dizziness, leg cramps, N/V, < folic acid, kidney stones, anemia (rarely)
What the drugs that interact with Potassium-Sparing diuretics?
Ace inhibitors, lithium, NSAIDS
What should I do if a pt has hyperkalemia?
Insulin may be given to move K+ into body cells, thereby reducing the serum level
What should I do if K+ > 5meq/L or if they are having dysrhythmias?
DC med & restrict potassium intake.
What are some things that i should tell pts who are taking Potassium-sparing diuretics?
Advise not to use salt substitutes: >K+
Women to report changes in voice, hair, menses/ Men sexual dysfunction, enlarged breasts
Triamterene may turn urine blue.
Name 2 Thiazide & Thiazide-LIke Diuretics: synthetic drugs r/t sulfonamides.
hydrochlorothiazide (HydroDIURIL AKA HCTZ): prototype thiazide diuretic.
Thiazide-like: metolazone (Mykrox, Zaroxolyn)
What is Thiazide and Thiazide-Like Diuretics: Mechanism of Action?
Inhibit tubular resorption of Na+ & Cl- ions
Action primarily in the ascending loop of Henle and early distal tubule
Result: water, sodium, and chloride are excreted
Potassium is also excreted to a lesser extent
Dilate the arterioles by direct relaxation
What are Thiazide and Thiazide-Like Diuretics: Drug Effects?
Lowered peripheral vascular resistance
Depletion of sodium and water
What are Thiazide and Thiazide-Like Diuretics: Therapeutic Uses?
Hypertension (one of the most prescribed group of agents for this)
Edematous states
Adjunct agents in tx of CHF, hepatic cirrhosi(problems w/ Liver)
What are Thiazide and Thiazide-Like Diuretics: Side Effects?
1.Major side effects=electrolyte disturbances: reduced K, Na, Cl, Mg
2. Hyperglycemia, hyperuricemia (may cause gout attack)
3. Can cause increased LDL, triglycerides, & total cholesterol.
4. Headache, impotence, decreased libido may be dose-related.
5. G
what should the nurse do when giving diuretics?What the nurse assess for? When should pts take this med?What should the nurse monitor?
Perform a thorough patient history and physical examination. Assess baseline fluid volume status, intake and output (I&O), serum electrolyte values, weight, vital signs.
Daily weights are best measure of fluid loss or retention
Assess for disorders that m
What should the nurse teach the pt?
Teach patients to maintain proper nutritional and fluid volume status.
Teach patients to eat more K+-rich foods when taking any but the potassium-sparing agents.
High in K+: bananas, oranges, dates, raisins, plums, fresh vegetables, potatoes, meat, & fish
What should the nurse tell the pt about positioning? daily weights & N/V?
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 & to return for follow-up visits and
What should the pt do if they are experiencing rapid HR or fainting?When should they report weight gain? What adverse effects should they look for?
Instruct patients to notify the physician immediately if they experience rapid heart rates or fainting (reflects hypotension or fluid loss).
A weight gain of 2 or more pounds a day or 5 or more pounds a week should be reported immediately.
Monitor for adv
What therapeutic effects should the nurse monitor for diuretic agents?
Reduction in edema, fluid volume overload, CHF
Reduction of hypertension
Return to normal intraocular pressure