Drug information of Metolazone


Metolazone is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention. Metolazone treats fluid retention (edema) in people with congestive heart failure, or a kidney disorder such as nephrotic syndrome. This medication is also used to treat high blood pressure (hypertension).

Mechanism of effect

The actions of Metolazone result from interference with the renal tubular mechanism of electrolyte reabsorption.


Metolazone is a quinazoline diuretic, with properties generally similar to the thiazide diuretics.


Peak blood levels are obtained within 2 to 4 hours of oral administration. 50-70% bound to erythrocytes, up to 33% bound to plasma proteins. Not substantially metabolized. 70-95% is excreted unchanged in urine.


Usual Adult Dose for Hypertension Initial dose: 2.5 mg orally once a day (Zaroxolyn) or 0.5 mg orally once a day (Mykrox). Usual Adult Dose for Edema Initial dose: 5 mg orally once a day (Zaroxolyn) or 0.5 mg orally once a day (Mykrox).

Drug contraindications

Anuria, , hepatic coma , precoma


1-Rarely, the rapid onset of severe hyponatremia and/or hypokalemia has been reported following initial doses of thiazide.. When symptoms consistent with severe electrolyte imbalance appear rapidly, drug should be discontinued and supportive measures should be initiated immediately. 2-Hypokalemia may occur with consequent weakness, cramps, and cardiac dysrhythmias. Serum potassium should be determined at regular and appropriate intervals. 3-Cross-allergy may occur when Metolazone tablets, USP, are given to patients known to be allergic to sulfonamide-derived drugs, thiazides, or quinethazone.

Points of recommendation

1-DO NOT INTERCHANGE UPSTATE'S Metolazone TABLETS, USP, ZAROXOLYN TABLETS, AND OTHER FORMULATIONS OF Metolazone. 2-Metolazone may raise blood glucose concentrations possibly causing hyperglycemia and glycosuria in patients with diabetes or latent diabetes. 3-Thiazide diuretics have exacerbated or activated systemic lupus erythematosus and this possibility should be considered with Metolazone tablets, USP. 4-advised to take the medication as directed, and promptly report any possible adverse reactions to the treating physician.

Pregnancy level


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