diuretics(mode of action)
potassium sparing diuretics
a)Aldosteron antagonist
ex:Amphenone _Spironolactone(Aldoctone is trade name )
Note:similar to aldosteron in chemical structure.
mode of action:competes with aldosteron for its receptors site in distal convoluted tubule and collecting duct which results in inhibition Na re-absorption,so excretion of water increases because Na attracts water
b)non aldosteron diuretics
ex:Amiloride (more potent and rapid onest)
Note:used combination with thiazide derivatives and loop diuretics.
mode of action:it inhibits Na/K exchange directly
cardiovascular diuretics
ex: xanthine derivatives(theophylline - aminophyline)
cardiac glycosides(strophanthus )
Note: have diuretic effect secondary to thier effect on cardiovascular system
mode of action:1-cardiac stimulation increase cardiac out put
2-improve circulation
3-dilatation renal blood vessels increases glomerular filteration rate
4-diuresis
used in:cardiac and renal odema
acidifying diuretics
ex:Ammonium chloride (NH4CL)Solutions of ammonium chloride are mildly acidic and CaCl
NH4CL--------->NH3+H+CL
mode of action:acidification to urine
used to :correct alkalosis for excretion of basic drugs as amphetamine.
mercural diuretics
ex:salygran -mersalygran
Note:rarely used and give alkaline urine so it is contraindication in equine
mode of action:1-decrease CL re-absorption
2-decrease Na re-absorption
3-decrease water re-absorption
Anti diuretics
ex:petressin tannate-ADH-synthetic ADH
definition :drugs decreases excretion of water
.
mode of action:stimulation anti diuretic hormone which result in re-absorption water from tubules
used in: treatment diabetes incipedus (disease characterized with increase amount and frequency of urination especially during night caused by insufficient ADH anti diuretic hormone)
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