What are the actions of diuretics?
Modify kidney function by increasing the rate of urine formation and excretion. It in turn removes Na and water.
What are the uses of diuretic drugs?
- Edematous conditions: CHF, renal and hepatic disease, ascites
- Non edematous: hypertension, glaucoma, neurologic
Can you name the 5 different classes of diuretics?
- 1. Osmotic
- 2. Carbonic Anhydrase Inhibitors
- 3. Loop Diuretics
- 4. Thiazide
- 5. Potassium Sparing
Where in the Renal Tubules do the different classes of diuretics effect?
- Proximal Tubule = Osmotics (mannitol) and Carbonic Anhydrase Inhibitors (Diamox)
- Loop of Henle= Loop Diuretics (furosemide)
- Distal Tubule= Thiazides (hydrochlorotiazide)
- Collecting Tubule= Potassium Sparing Diuretics (aldactone)
What are the actions of Mannitol?
- Osmotic - Increase osmotic pressure of the filtrate at the glomerulus.
- Results in rapid diuresis by increasing solute load --pulls water from tissues.
What is Mannitol indicated for?
- *Intraoccular pressure (Glaucoma)
- Because it pulls the fluid from the brain into the vessels.
- *Acute Renal Failure in "low flow" conditions (dehydration, hypotension, hypovolemic shock)- flushes the kidneys
- Overdose - not often
What routes are safe when administering mannitol?
- IV only.
- onset 30 minutes , lasts 6-8 hours
What is a major contraindication of Mannitol?
caution in Cardiac Heart Failure patients. Mannitol draws fluid into the vessels which increases the work load of the heart.
also caution with anuria, severe pulmonary edema, severe dehydration, children<12 yo, pregnancy
What are some adeverse effects of osmotic diuretics?
- Pulmonary edemaTachycardia
What are the actions of Acetazolamide?
Increases osmotic pressure resulting in diuresis by preventing reabsorption of bicarbonate ions from proximal tubule
Which diuretic lowers intraocular pressure and is a common therapy for glaucoma and altitude sickness?
it is also indicated (though not used often) for management of seizures and overdoses
What are the side effects of Acetazolamide?
Diamox= Headache, nervous, ataxia, alopecia,
, anorexia, decrease K+, may increase BG
- MAY increase serum glucose,
- Potassium Wasting.
What are the contraindications and precautions with Acetazolamide?
- Should not use if you are allergic to sulfanomides, have renal or respiratory acidosis, or liver impairment
- You can develop a tolerance with long-term use.
Which drug is less potent than loop diuretics and thiazides?
Carbonic Anhydrase Inhibitor- the metabolic acidosis they induce reduces their diuretic effect in 2 to 4 days
CIAs= Acetazolamide (Diamox)
What diuretic is most frequently used and where do they effect the renal tubule?
- Loop Diuretics=
- Lasix (furosemide)
- Bumex (bumetamide)
- Edecrin (ethacrynicacid)
- Demedex (Torsemide)
- ** Effect the Loop of Henle
What diuretic has a renal vasodilation effect and inhibits sodium reabsorption in the ascending loop?
Loop diuretics- Lasix (fureosemide)
What are the indications of lasix?
- 1. Pulmonary edema, ARF
- 2. Severe edema due to CHF, kidney or liver disease
- 3. Hypertension
- 4. Hypercalcemia - promotes Ca excretion
- 5. Management of acites- fluid in abdominal cavity?
Drug of choice when rapid effects are required: ARF, pulm. edema
Which of the following diuretics has a saluretic effect (Na excreting) 10x greater than the other?
a. Lasix (furosemide)
b. Hydodiuril (HCTZ)
The loop diuretic -Lasix (furosemide)
What are some common side effects of Lasix (furosemide)?
And what are some significant Adverse effects?
- Hypokalemia - Potassium wasting*
- Orthostatic Hypertension
- anorexia, abdominal discomfort, weakness, muscle cramps- usually due to low K+
- cn 8 damage, photosensitivity, alkalosis, Hyper-glycemia & uricemia (dont give with gout), hypo- ca & mg
What diuretic has the adverse effect of tinnitus and hearling that may be irreversible when given IV?
Loop Diuretics - Lasix (furosemide)
What are the contraindications of Loop diuretics?
- -Anuria (don't give to patients with gout)
- - Electrolyte depletion and hypotension
- - Dehydration
- - Pregnancy (use with caution)
- - Infants
- - Hepatic coma
- **Monitor diabetics for hyperglycemia
Loop Diuretics: Onset and rule of thumb
- Quick onset with IV and PO
- Rule of thumb: give IV slowly to prevent CN 8 damage
Which diuretics should you use caution in patients with diabetes, gout, cardiac arrhythmias and pregnancy?
- Thiazides- Hydordiuril (hydrochlorothiazide) also becareful if you are allergic to sulfanomides
- & Loop Diuretics - Lasix (furosemide)
What diuretic acts on the distal tubule, inhibit sodium reabsorption and decrease peripheral vascular resistance?
- Hydrodiuril (Hydrochlorotiazide)
What are some disadvantages of using Thiazide?
- 1. Hypokalemia
- 2. Hyperglycemia
- 3. Reduced uric acid excretion- uric acid causes gout, stones
- 4. Orthostatic Hypotension
- 5. Cardiac dysrhythmias
- 6. Impotence and decreased libido (only one different than lasix)
What are the indications of Thiazide?
- 1. Mild hypertension- potentiates ACE inhibitors
- 2. Mild edema- from CHF, hepatic cirrhosis, or cotricosteroid & estrogen therapy
What are the main differences between Thiazides and Loop Diuretics?
- -mostly given PO (w. no IV available),
- -absorbed within 2 hrs and excreted in 3-6 hours
- -less potent than loop
- -Side effect = HYPERcalcemia
- -Given PO and IV
- -Rapid acting
- - Extremely potent and rapid
- -IV effectiveness improves in combo w. thiazide (zaroxolyn)
- -Side effect= HYPOcalcemia
What is type of diuretic is Zaroxlyn (____) and what is it usually taken in combination with?
- -Zaroxlyn (metolazone) is a Thiazide!
- -Usually combine with loop diuretics because it potentiates the action.
When should you administer Zaroxolyn and what route should you use?
- -Administer 30 min prior to Loop diruetic
- -Must be given PO or NG (NO IV DOSE AVAILABLE!)
What diuretic blocks sodium reabsorption by preventing the effects of Aldosterone in the distal tubule?
- Potassium Sparing Diuretics -- Aldactone (Spironolactone)
- -Has similiar effects of Loop and Thiazide because it increases excretion of Na and water BUT it conserve K+. (SO it is not potassium wasting like the others)
What are the indications of Aldactone?
- 1. Patients at risk of hypokalemia
- 2. Hyperaldosteronism- seen in cirrhosis of liver and nephrotic syndrome
- 3. Hypertension and edema
- 4. Has additive effect when used with other diuretics – often included in combination drugs to decrease BP and edema
The following side effects are seen in which diuretic? Hyperkalemia, lethargy, confusion, ataxia, hypotension, GI distress, leg cramps, dizziness, gynecomastia in men, menstrual irregularities and hisutism (hairyness) in women
What are the contraindications while taking Potassium Sparing Diuretics?
- 1. Renal Insufficiency
- 2. Hyperkalemia
- 3. Prenancy
What drug's effects are decreased with salicilates?
While using which drug should patients be monitored closely for hyperkalemia and taught the warning signs (nausea, diarrhea, lethargy, confusion, ataxia)?
Where sodium goes, _____ follows.
20-25% of sodium is absorbed in _____.
5-10% of sodium is absorbed in ______.
3% of sodium is absrobed in ______.
- Where sodium goes WATER follows.
- -20% to 25% - loop of Henle
- -5% to 10% - distal tubules
- -3% -collecting ducts
- Whatever is not absorbed is excreted.