HTN Pcol (MOA) Exam With Complete Solution
Chlorthalidone (and hydrochlorothiazide)
Blocks the Na-Cl cotransporter in the distal convoluted tubule. Increases excretion of
sodium chloride and water and potassium.
Triamterene
Blocks the epithelial sodium channels in the collecting duct with a decrease in sodium
reabsorption from the lumen.
Spironolactone
Inhibition of aldosterone on mineralocorticoid receptor sites in the collecting duct
leading to increased excretion of sodium and water with sparing of potassium and
hydrogen ions is KP sparing diuretic .
Loop Diuretics
Acts through inhibition of sodium and chloride reabsorption from loop of Henle because
of interference with Na / K / Cl cotransporter which increases the excretion of water,
sodium, chloride, magnesium, and calcium
SNG
Lisinopril
It is a competitive inhibitor of ACE enzyme so blocks conversion of Angiotensin I to
Angiotensin II that is a powerful vasoconstrictor and results in vasodilatation and
reduced aldosterone secretion. Degradation of bradykinin is also blocked.
Doxazosin
Selectively block alpha-1 receptors on vascular smooth muscle which results in
peripheral vasodilation of arterioles and veins.
Clonidine
Chlorthalidone (and hydrochlorothiazide)
Blocks the Na-Cl cotransporter in the distal convoluted tubule. Increases excretion of
sodium chloride and water and potassium.
Triamterene
Blocks the epithelial sodium channels in the collecting duct with a decrease in sodium
reabsorption from the lumen.
Spironolactone
Inhibition of aldosterone on mineralocorticoid receptor sites in the collecting duct
leading to increased excretion of sodium and water with sparing of potassium and
hydrogen ions is KP sparing diuretic .
Loop Diuretics
Acts through inhibition of sodium and chloride reabsorption from loop of Henle because
of interference with Na / K / Cl cotransporter which increases the excretion of water,
sodium, chloride, magnesium, and calcium
SNG
Lisinopril
It is a competitive inhibitor of ACE enzyme so blocks conversion of Angiotensin I to
Angiotensin II that is a powerful vasoconstrictor and results in vasodilatation and
reduced aldosterone secretion. Degradation of bradykinin is also blocked.
Doxazosin
Selectively block alpha-1 receptors on vascular smooth muscle which results in
peripheral vasodilation of arterioles and veins.
Clonidine
