Loop diuretics

diuretic drug

- Blocks sodium from being reabsorbed from the tubules into the blood.

- As the sodium is excreted in the urine, it brings water and potassium with it.

- This decreases the volume of blood and is used to treat hypertension, congestive heart failure, and nephrotic syndrome.

carbonic anhydrase inhibitors

Treat glaucoma

Decreases aqueous humor production

Diuresis

Diamox is an example

loop diuretics

furosemide, bumetanide, torsemide

ascending limb, dilation, edema

loop diuretics mechanism of action:

- Possess kidney, cardiovascular, and metabolic effects

- Act directly on the ______ _______ of the loop of Henle to block chloride and sodium resorption

- Increase kidney prostaglandins, resulting in the _______ of blood vessels and reduced kidney, pulmonary, and systemic vascular resistance

- Useful in treatment of _______

diuresis, fluid volume, potassium and sodium

loop diuretic drug effect:

- Rapid onset; last at least 2 hours

- Potent ______ and subsequent loss of fluid

- Decreased _____ ________ causes a reduction in:

→ Blood pressure, Pulmonary vascular resistance, Systemic vascular resistance, Central venous pressure, and Left ventricular end-diastolic pressure

- _______ and ______ depletion

Small calcium loss

loop diuretic indications

- Edema associated with heart failure and liver or kidney disease

Hypertension (to control)

- Kidney excretion of calcium in patients with hypercalcemia (to increase excretion)

- Heart failure resulting from diastolic dysfunction

loop diuretic adverse effects

- Central nervous system = dizziness, headache, tinnitus, blurred vision

- Gastrointestinal = nausea, vomiting, diarrhea

- Hematological = agranulocytosis, neutropenia, thrombocytopenia = high risk of infection

- Metabolic = hypokalemia, hyperglycemia, hyperuricemia

NOTE THINK ABOUT WHEN YOU ARE DEHYDRATED

loop diuretic interactions

- Increase serum levels of uric acid, glucose, alanine aminotransferase, and aspartate aminotransferase.

thiazide (metolazone): sequential nephron blockade

- Nonsteroidal anti-inflammatory drugs (NSAIDs) may decrease the reduction of vascular resistance

Ex. aspirin = use in caution

osmotic diuretics

Mannitol

Treats Edema, increased ICP, increased IOP

Contraindicated in intracranial hemorrhage

"Oh man I had a bad headache because of increased cranial pressure, but man it all went away when I took mannitol"

Reduces ICP and IOP by increasing serum osmolality

Side effects: Heart failure, pulmonary edema, renal failure, dehydration, electrolyte imbalances

Use filter needle and tubing when admintering

Monitor weight, I&Os, and electrolytes

potassium-sparing diuretic

aldosterone-inhibiting diuretics + used if they cannot tolerate the other diuretics

Ex. amiloride (Midamor®), spironolactone (Aldactone®), triamterene, triamterene in combination with hydrochlorothiazide

collecting duct and distal convoluted tubule

potassium-sparing diuretic mechanism of action:

work in ______ _____ and ____ ______ ____

= interfere with SODIUM-POTASSIUM exchange

= competitively bind to ALDOSTERONE receptors --> block resorption of sodium and water usually induced by aldosterone secretion

Potassium Sparing Diuretics

drug effect:

- relatively weak compared with the thiazide and loop diuretics

- Competitively block aldosterone receptors and inhibit their action

- Promote the excretion of sodium and water

Potassium Sparing Diuretics indications

pironolactone and triamterene:

- Hyperaldosteronism

- Hypertension

- Reversing potassium loss caused by potassium-wasting diuretics

- Certain cases of heart failure

- Hyperkalemia = clotting, tachycardia, dysrhythmia, and mi

Potassium sparring diuretics adverse effects

- central nervous system = dizziness, headache

- Gastrointestinal = cramps, nausea, vomiting, diarrhea, Urinary frequency, weakness, hyperkalemia

spironolactone

potassium sparing diuretic:

- Gynecomastia

- Amenorrhea

- Irregular menses

- Postmenopausal bleeding

Interactions:

Lithium

Angiotensin-converting enzyme inhibitors

Potassium supplements

NSAIDs

Thiazide and Thiazide-like Diuretics

Thiazide diuretics: hydrochlorothiazide (Urozide®)

Thiazide-like diuretics: metolazone (Zaroxolyn®), chlorthalidone, indapamide

Mechanism of action:

tubular resorption, distal convoluted tubule, dilate

Thiazide and Thiazide-like Diuretics mechanism of action:

- Inhibit ______ ______ of sodium, chloride, and potassium ions

- Action primarily in the _______ ____ _____

Result in osmotic water loss

- _______ the arterioles by direct relaxation

-Decrease preload and afterload

- Thiazides should not be used if creatinine clearance is less than 30 to 50 mL/min (normal is 125 mL/min).

Thiazide and Thiazide-like Diuretics indications

- Hypertension (one of the most prescribed group of drugs for this)

- Edematous states

- Idiopathic hypercalciuria (Ca kidney stones)

- Diabetes insipidus

- Heart failure caused by diastolic dysfunction

Thiazide and Thiazide-like Diuretics adverse effects

- Central nervous: dizziness, headache, blurred vision

- Gastrointestinal: anorexia, nausea, vomiting, diarrhea

- Genitourinary: erectile dysfunction

- Hematological: jaundice, leukopenia, agranulocytosis

- Integumentary: urticaria, photosensitivity

- Metabolic: hypokalemia, glycosuria, hyperglycemia, hyperuricemia, hypochloremic alkalosis

furosemide

- increase urination = remove excess fluid

- lowers blood pressure

furosemide indications

- hypertension

- pulmonary edema

- edema

- hypercalcemia

caused by: heart failure, liver impairment, kidney disease, ascites

furosemide patient history

- allergies

- kidney or liver dysfunction

furosemide assessments

- vital signs

- edema

- capillary refill

- skin assessment

furosemide adverse effects

- dehydration

- electrolyte loss

- dizziness

- syncope

liver function

furosemide lab work:

- alkaline phosphate

- aspartate aminotransferase

- lactate dehydrogenase

kidney function

furosemide lab work:

- blood urea nitrogen

- creatinine

serum electrolytes

furosemide:

- potassium

- sodium

- chloride

- magnesium

- calcium

- uric acid

nursing interventions

furosemide:

heart: rate and rhythym

diet: signs of constipation, increase intake of fluids and fibre

medications: take @ same time to enhance therapeutic effect + do not administer after 5pm = prevent nocturia

other: use of commode, incontinence pad, water on bedside table, change position slowly

patient teaching

furosemide:

- ORTHOSTATIC hypotension = fall risk

- potassium-rich diet + proper fluid intake

- weight gain journal

- rash, muscle weakness, cramps, nausea, dizziness, numbness, tingling

- S/S of digoxin toxicity and hypokalemia

- HTN medication adherence

urinary output

furosemide desired outcome = increase in?

blood pressure, edema, weight, abdominal girth

furosemide desired outcome = decrease in?

older adult relevance

furosemide:

- effective with kidney impairment

- rapid onset

- cross-reaction = unlikely

- multiform

= higher risk of dehydration, falls, and hypotension

medication challenges

furosemide:

- adverse reactions

- non-adherence

- impairment