Medications acting on the Nephron (Diuretics) Flashcards
Diuretic MOA
Blockade of sodium and chloride reabsorption
Diuretic Site of Action
Proximal tubule produces greatest diuresis
Diuretic Adverse Effects
Hypovolemia
Acid-base imbalance
Electrolyte imbalance
Diuretic Cardiovascular Effects
Decreasing preload and afterload
Four Classifications of Diuretics
- Loop - Furosemide
- Thiazide: Hydrothorothiazide
- Osmotic: Mannitol
- Potassium-Sparing:
4a. Aldosterone antagonist
4b. non-aldosterone antagonist.
Loop Diuretics - Prototype?
Furosemide (Lasix)
Furosemide MOA
Acts on ascending Loop of Henle to block reabsorption
Furosemide Pharmacokinetics
Rapid onset - PO 60 mins
IV 5 mins
Furosemide Therapeutic uses
HTN
Pulmonary edema
Edematous states
If you have severe renal impairment with a patient, what diuretic would you use?
Furosemide (Loop Diuretic) as a HTCZ (Thiazide) Diuretic would not work.
Diuretic Side Effects
Hypovolemia
Hypotension
Hypokalemia
Ototoxicity - cautionary as there is transient deafness present
Thiazide Diuretic MOA
Acts on the Distal Convoluted Tubule (DCT).
MOA - increases renal excretion of Na+, Cl-, K+, and water.
Elevates uric acid and glucose
Thiazide Diuretic - Diuresis
LOWER than Loop diuretics
Therapeutic use of Thiazide Diuretics
Essential HTN
Edema
Diabetes Insipidus
HCTZ Side Effects
DO NOT USE IN PREGNANCY
Hyponatremia, Hypochloremia, dehydration
Hyperglycemia
Hyperuricemia
Impacts lipids, calcium, and mag
Osmotic Diuretic - Mannitol MOA
Promotes diuresis by creating an osmotic force w/ the lumen of the nephron
Drug must be given parenterally - hard push
Acts on the descending limb of the Loop of Henle
Osmotic Diuretic - Mannitol - Therapeutic use
Reduction of ICP via the constricting the capillaries to decrease fluid allowance out of the vasculature
Reduction of intraoccular pressure
Prophylaxis for Renal Failure
Potassium-Sparing Diuretics MOA
Blocks aldosterone in the distal nephron (Collecting ducts) and RETAINS potassium while increasing the excretion of Na+
Potassium Sparing Diuretic Medications
Spironolactone
Eplerenone
Potassium Sparing Diuretic Therapeutic uses
HTN
Edema
Heart failure (decreases mortality)
Potassium Sparing Diuretic Side Effects
HYPERKALEMIA
Endocrine effects such as gynecomastia, impotence, deepening of the voice
Potassium Sparing Diuretic Interactions
Thiazide, & Loop Diuretics or ANY AGENTS RAISING POTASSIUM LEVELS (Potassium supp, ACEI, ARBs, renin inhibitor