Name: Metolazone (Mykrox)
Class: Diuretic (Thiazide-Like)
Mechanism: Inhib. Na+ & Cl- transport in the cortical thick ascending limb and the early distal tubule ® NaCl and water excretion, & ¯ excretion of Ca2+ and uric acid.
Absorption: Oral ® good absorption. Takes effect in 1 hr.
Dist.: Metabolism.: Excretion, t½:
Toxicity/S.E.s: Hypokalemia, hyponatremia, hyperuricemia, hypercalcemia, Metabolismolic alkalosis, postural hypotension, hyperglycemia (in patients w/DM), and rare hypersensitivity rxns. C/i—pts susceptible to problems w/hypokalemia (cirrhosis, pts on digitalis), hyperuricemia (gout), or hypercalcemia.
Utility: The only distal nephron diuretic efficacious in patients w/severe renal insufficiency. Treat hypertension, CHF, nephrotic synd., other Na+-retaining states. Reduce Ca2+ excretion (e.g., prevention of kidney stones).
Special Features: Strongest inhib. of Na+ & water reabsorption of the thiazide and thiazide-like diuretics. Often given in comb. w/a loop diuretic. Milder diuretic action than loop diuretics.