Diuretics- Melissa (3)* Flashcards
Three primary uses for diuretic drugs:
- Mobilize Fluid (during increased ICP/ IOP)
- Excrete Fluid (edema)
- Excrete Electrolytes (Na+)
Acetazolamide:
Drug class
MOA + LOA*
Carbonic Anhydrase Inhibitor
*Acts on PROXIMAL TUBULE
- Decreases intracellular CA–>
- Low intracellular H+ HCO3-
- Decrease Na/H+ luminal XGE = low Na reabsorption
- Decrease Na/HCO3- basolateral cotransport= low Na reabsorption
- Decrease Na/K basolateral cotransport = low K reabsorption
Net effect:
2. Decrease luminal CA, Increase Luminal HCO3-, Na+, K+ for excretion
What are 3 effects of Acetazolamide use?
- Weak diuretic (^Na excretion, 5%* filtered load)
- ^^^ HCO3- excretion–> acidosis*
- ^ K+ excretion —> hypokalemia
3 Therapeutic uses for acetazolamide:
When is it NOT used?
Open angle glaucoma, Mountain sickness, Urinary alkalization (rid acidic toxins)
*NOT used as diuretic
Note: treats mountain sickness by acidifying blood, which stimulates respiration. Else, due to ^^^ bicarbonate in blood, patients will lose respiratory drive at night/ maybe die in their sleep.
What is Hyperchloremic Acidosis? Why is it important to acetazolamide use?
Acidosis resulting from acetazolamide use: excretion of HCO3- causes acidosis with ^ Cl-
Compensatory mechanisms will respond to acidosis–> negate the diuretic effects–> ineffective diuretic
3 important side effects to acetazolamide use:
Hyperchloremic acidosis, Hypokalemia, HYPERSENSITIVITY (Sulfadrug)
List Three Thiazide Drugs:
MOA (2) / LOA
- Hydrochlorothiazide***
- Chlorothiazide
- Polythiazide
(Most end in thiazide, except special renal ones and chlorthalidone)
MOA DISTAL TUBULE :
- Binds Cl- binding site–> STOP luminal Na/Cl cotransport
- Decrease Na Reabsorption by 10%
List two Thiazide related drugs:
MOA/ LOA
When are these particularly useful?
- Metolazone
- Indapamide
MOA DISTAL TUBULE :
- Binds Cl- binding site–> STOP luminal Na/Cl cotransport
- Decrease Na reabsorption
***TX PATIENTS WITH POOR RENAL FXN
Give to indaPAMide + METOOlazone, (Pam and Me too) cause we have jacked up kidneys.
What do thiazides/ related drugs do to the urine (4)?
What patients would these be good to treat?
What patients would these be bad to treat?
- Modest Diuretic (^ Na excretion 10% Filtered load)
- ^ K /Cl /HCO3 excretion
- DECREASE Ca+ excretion–> GOOD for OSTEOPEROSIS***
- DECREASE URIC ACID excretion–> BAD for GOUT***
5 Clinical indications for thiazide/ related drug use
HTN, Edema States (CHF, Cirrhosis), Ca2+ Kidney Stones, Nephrogenic DI (^ +feedback), Nephrotic Syndrome (+SP)
SE of Thiazides/ related drugs (5-hyper, 1 hypo)
- Excessive MOA, HYPERSENSITIVITY (sulfa), Hyperglycemia (Diabetes)/ Hyperlipidemia (long term tx), Hyperuricemia
- Hypovolemia (rare)
Describe the drug-drug interaction between thiazides/related drugs and digitalis
Hypokalemia induced by thiazides/ related drugs will ^ efficacy of the digitalis–> toxicity
Careful with CHF patients!
What is the relationship between thiazides/ related drugs and the GFR?
GFR must be GREATER THAN or EQUAL to 30-40 ml/min for drug to work!
(EXCEPT for IndaPAMide + METOOlazone )
Which two thiazide related drugs are effective in patients with GFR LESS than 40 ml/min
Metolazone, Indapamide
Which diuretics are the most effective?
Loop diuretics
List three loop diuretics that are sulfa drugs
- Furosemide
- Bumetanide
- Torsemide
(All of the IDEs)
LOOPY FURry BUM TORtoise
(FURuity LOOPS BUMp TOgether in my cereal)