Renal Pharmacology

Golden Rule: Water tends to follow sodium.

source

Mannitol MOA 

osmotic diuretic, increases tubular fluid osmolarity, producing increased urine flow

Hydrochlorothiazide MOA

inhibits NaCl reabsorption in the early distal tubule

Loop diuretics MOA

inhibits cotransport system (Na+, K+, 2Cl-)  in the thick ascending limb of loop of Henle
*abolishes hypertonicity of medulla, preventing concentration of urine

Acetazolamide MOA

carbonic anhydrase inhibitor
*causes self-limited NaHCO3 diuresis and reductions in total body HCO3- stores
 in the proximal convoluted tubule