This document discusses different classes of diuretic drugs based on their site of action in the nephron. It defines diuretics as drugs that increase urine output and lists the four major sites where diuretics act - the proximal convoluted tubule (PCT), the thick ascending limb of Henle's loop, the distal convoluted tubule (DCT), and the collecting tubule. It provides examples of diuretic drugs that act at each site such as carbonic anhydrase inhibitors at site 1, loop diuretics at site 2, thiazide diuretics at site 3, and potassium-sparing diuretics at site 4. It also briefly discusses the mechanisms of action, effects

1. DIURETICS
by
SROTA DAWN.
B.PHARM(3RD YEAR)

2. Definition: A diuretic can be
defined as a chemical that
increases the rate of urine
formation.
The PRIMARY ACTION: Direct
inhibition of Na+ transport along
one or more of the four major
anatomical sites.

3. 4 major
sites of
nephron:
SITE 1 : The “PCT”
SITE 2 : The thick
ascending limb of
“HENLE’s LOOP”
SITE 3 : The “DCT”
SITE4:The“collecting
tubule &
cortical collecting
Tubule”

4. SITE OF
ACTION
TYPE OF
DIURETICS
EXAMPLES
1. SITE 
DIURETICS
Carbonic anhydrase
inhibitors
Acetazolamide
, methazolamide
, dichlorphenamide
etc.
2. SITE 
DIURETICS
Loop diuretics organomercurals,furos
emide,bumetanide,azo
semideetc
3. SITE 
DIURETICS
Thiazide & thiazide like
diuretics
Chlorthiazide,
benzthiazide,
hydrochlorthiazide etc.
4. SITE 
DIURETICS
Potassium-sparing
diuretics
Spironolactones
Triamterene,amiloride
5.OTHERS Osmotic diuretics Mannitol, Isosorbide,
glycerol

5. SITE 1 DIURETICS:
CARBONIC
ANHYDRASE INHIBITORS
MOA:INHIBITION OF
CAase
1. intracellularly
2. In luminal brush
border
effects:
reabsorption of
Na+,HNO3-
Seondary effect:
 excretion of K+
USE:
1.Glaucoma
2.Promote exeretion of
weakly acidic drug
3. In epilepsy
4. Acute mountain
sickness
ADR:
1. metabolic acidosis
2.hypokalemia
3.20%  in GFR
4.sulphonamide associat
ed hypersensitivity reactions.

6. SITE 2 DIURETICS:
HIGH- CEILING Or LOOP DIURETICS
MOA:
1.Inhibit the 1Na+/1K+/2Cl-
cotransport system
EFFECTS:
Reabsorption of Na+, K+,C l-
Use:
1.edemacardiac,hepatic,renal
2.Acute pulmonary edema
associated with CHF
3.HYPERCALCAEMIA & Renal
calcium stones
ADR:
1.Sulfnamoyl moiety associated
hypersensitivity reactions
2.Hypokalemia intensifies the
Toxicity of cardiac glycosidesSITE 2: Henle's loop

7. SITE 3 DIURETICS:
THIAZIDE DIURETICS
MOA:
All of these diuretics block the
Na+ reabsorption by inhibiting
The LUMINAL MEMBRANE
bound Na+/Cl- cotransport
system
Effects:
Naturetic,chloruretic,saluretic,
kaluretic& weak
bicarbonaturetic
Use:
1.edema associated CHF
2.hypertension(uncomplicated)
ADR:
1.Hypersensitivity reaction
2.Hypokalemia
3.cardiac output

8. SITE 4 : COLLECTING TUBULE&
CORTICAL COLLECTING TUBULE
SITE 4 DIURETICS:
POTASSIUM SPARING
DIURETICS
MOA:
SPIROLACTONEs:
inhibit reabsorption of Na+ by
compititively inhibiting the actions
of ALDOSTERONE
OTHERS:
Plug the Na+ channels of
Luminal membrane
EFFECTS:
Na+,Cl- exeretion without
Concomitant increase in
urinary excretion rate of K+
USE:
1.Combination therapy with
site 2&3 diuretics
2.Mild edema associated CHF
3.HYPERTENSION

9. OTHERS:
MANNITOL:
High luminal fluid concentration of mannitol create an
osmotic effect .this effect prevents the reabsorption of
Water.
Use:
Used in hospital setting to keep the nephrons open.
Decrease CSF volume & pressure.

10. THANK YOU