L55 Flashcards
4 reasons to use acetazolamide
- Glaucoma
- Metabolic alkalosis
- Altitude sickness
- Periodic paralysis - hypo + hyperK
4 SE of acetazolamide
Drowsiness
Dizziness
Headache
Fatigue
Is the diuresis from mannitol water or osmotic?
Large vol WATER - ↓U Na
Osmotically active - don’t block specific ion transport channels
3 reasons to use IV mannitol
- ↓ICP
- Forced diuresis - lose water
- Free radical scavenger (rhabdo)
SE of mannitol
Intravasc expansion - might increase ICP or worsen CHF/pulm edema before starts working… be careful
What disease state induces an osmotic diuresis?
Diabetes
Excess glucose in urine -> diuresis
Why diabetics so thirsty!!
Which diuretics are ceiling diuretics?
Loop: must achieve lower threshold [ ] to achieve diuresis
If increase drug dose above therapeutic window, no additional effects
Type of diuresis caused by loop diuretics
Isosthenuric
4 loop diuretics you need to know
Furosemide - variable oral availability, sulfa allergy, weak CA inhibitor (PCT), direct vasodilator
Torsemide - more avail but still sulfa allergy
Bumetanide “ “
Ethacrynic acid - no allergy and good avail but no one makes it
4 uses for loop diuretics
- Edema to due intravasc vol depletion: CHF, acute pulm cong, cirrhosis, nephrotic syndrome
- HTN
- ↑Ca
- Forced diuresis
5 SE of loops
- Lose too much vol = intravasc vol depletion: circulatory collapse, ↑BUN
- ↓K - arrhythmia
- ↓Ca
- ↓Mg
- Ototox - blocks 2Cl/K/Na in the ear!
U osm created by thiazides
Urine is either isotonic or hypertonic
Inhibits ability to produce a dilute urine
Added benefits of thiazides
Direct vasodilator
What drug do you use to treat nephrogenic diabetes insipidus (kidney doesn’t respond to ADH)?
Volume depletion inhibits polyuria
You’re wasting Na and thus water, as your body realizes your hypoNa, it starts to find ways to hold onto water in other ways
2 thiazides you need to know
HCTZ - limit to vasodilation and diuretic effects
Metolazone - larger diuresis b/c also has sign prox tubular effects
Which pts do you NEVER give thiazides to?
HypoNa
Also ineffective if GFR
4 indications to give thiazides
- HTN - 1st choice!!!
- Edema
- Nephro DI
- Hyper-Ca-URIA aka ↑risk kidney stones - works by ↑volume of urine, more dilute
SE of thiazides
HypoNa HypoK High cholesterol and diabetes - benefits out weigh risks HyperCa Hyper-uricemia ↑BUN
Indication + 2 SEs for amiloride and triamterene
ENAC blockers Use = ascites due to cirrhosis SE: - Hyper K - Hypotension
What do you add to HCTZ to prevent hypoK?
Triamterene = ENAC blocker
3 indications for spironolactone
- Cirrhosis (ascites)
- CHF - SURVIVAL benefit proven
- Hyperaldo
SE spironolactone
HyperK
Hypotension
Gynecomastia + erectile dysfxn
What is the theory for synergistic use of diuretics?
No benefit by using 2 of the same type Use those that sequentially block the nephron Ex: - Loop + thiazide - Loop + K sparing
What organ is the primary target of toxicities due to diuretic therapy?
Kidney - b/c drugs really only build up in [ ] in the tubular fluid
Otherwise, vestibular fluid -> hearing SEs
Why not use loop or thiazides w/ digitalis?
HypoK -> dig tox
Why not use ACE inhibitors w/ K sparing?
HyperK -> arrhythmia
Why not use NSAIDs w/ loop or thiazide?
↓Diuretic effect
Why not use probenecid (gout) with loop or thiazide?
↓Diuretic effect
Which diuretics are hugely salt wasting?
Most = thiazide
Large salt waste from loop and K
