Diuretics
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Transcript of Diuretics
DIURETICS
Presentation by- Syed Baseeruddin Alvi M.Pharm-Pharmacology(09)
INTRODUCTION
• Diuretics are the drugs which causes a net loss of sodium and water in urine
• They are used to reduce the abnormal accumulation of excess fluid in the body
• act to modulate different processes to reduce sodium and water reabsorption, resulting in increased water excretion
How can all diuretics show same action…….?
A sneak peek into the nephron…….!
Types of diuretics…….
Carbonic anhydrate inhibitors…….
• An enzyme – interconvertion b/w carbon di oxide and carbonic acid
• Site of action – PT• Na+ is carried by Na+/H+ antiport• Energy comes from down hill
moment of Na+
Acetazolamide
Dichlophenamide
Osmotic diuretics……. Glycerin Mannitol
Site of action – loop of Henle
It shows action by two ways
1. Extracts water from interstitial spaces
2. Extracts water from intracellular compartment
Increasing osmolarity of the filtrate
Reducing blood viscosity & medullary osmotic gradient
High ceiling diuretics(inhibitors of Na+/K+/2Cl- symport)…
Site of action – Thick ascending limb
Flux of ions is mediated by symporter
Overall transport causes extraction of
Nacl from lumen to medullary spaces
Transported Nacl is responsible in
generating & maintaining medullary
osmotic gradient
Inhibits the reabsorption of up to 25% of Na+, hence known as high ceiling Furosemide
Bumetanide
Inhibitors of Na+/Cl- symport…….
• They are also known as thiazide or
thiazide like diuretics.
• Site of action – Distal tubule
• Symporter moves Cl- into the cell
against its electrical gradient (active)
• Na+ entry is passive where as exit
is active process.
• Thiazides fight for Cl- binding site…
• Moderately effective (i.e 5%)
Hydrochlorothiazide Metolazone
Inhibitors of renal epithelial Na+ channels….
• They are known as k+ sparing diuretics
• Site of action – late distal tube &
collecting duct
• Na+ influx provides driving force for
secretion of k+
Amiloride
Triamterene
Antagonist of mineralocorticoid receptor….
ADR
AD ADRC
AIP
Inactive Na+ channels get activated
spironolactone
lumen Interstitial space