Informational only — Not medical advice. Always consult a licensed healthcare provider.

Community data Updated 2 months ago

Indications

Merozolyn is used to relieve fluid retention (edema) linked to congestive heart failure, as well as edema arising from kidney disease, including nephrotic syndrome and reduced kidney function. The 2.5 mg strength is also prescribed for mild to moderate essential hypertension, either on its own or alongside other classes of blood pressure-lowering medicines.

⚠️ Always consult a registered physician before taking any medicine.

Pharmacology

Metolazone is a diuretic antihypertensive drug for the treatment of edema. Merozolyn is a quinazoline diuretic, with properties generally similar to the thiazide diuretics. The actions of Merozolyn result from interference with the renal tubular mechanism of electrolyte reabsorption. Merozolyn acts primarily to inhibit sodium reabsorption at the cortical diluting site and to a lesser extent in the proximal convoluted tubule. Sodium and chloride ions are excreted in approximately equivalent amounts. The increased delivery of sodium to the distal-tubular exchange site results in increased potassium excretion.Merozolyn does not inhibit carbonic anhydrase. A proximal action has been shown in humans by increased excretion of phosphate and magnesium ions, and by a markedly increased fractional excretion of sodium in patients with severely compromised glomerular filtration.The antihypertensive mechanism of action of metolazone is not fully understood but is presumed to be related to its saluretic and diuretic properties.Pharmacokinetics: Metolazone is absorbed rapidly; however, rate and extent of absorption is dependent on the formulation. Clinical studies have shown that ninety to nine-five percent of metolazone is bound to red blood cells and plasma protein. The prolonged duration of action of metolazone is attributed to its protein binding and allows for once a day dosing. Only a small amount of metolazone is metabolized. Most of the drug is excreted in the unconverted form in the urine. When Metolazone is given, diuresis and saluresis usually begin within one hour and persist for 24 hours depending on the dose. The effect may be prolonged beyond 24 hours particularly at the higher recommended dosages.

Pregnancy & Breastfeeding

Use in Pregnancy: Metolazone crosses the placenta and appears in cord blood, so its use in women of childbearing age requires weighing the drug's potential benefits against its possible hazards to the fetus. Potential effects on the fetus include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have been observed in adults. However, teratogenic studies in mice, rats, and rabbits have not shown teratologic effects in these animals.

Nursing Mothers: Metolazone appears in breast milk. It is therefore possible that effects seen with metolazone use may occur in the nursing infant. If use of metolazone is considered essential for a nursing mother, she should stop breastfeeding.

⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.

Dosage Reference

⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.

Adults: Effective dosage of Metolazone should be individualized according to indications and patient response. A single daily dose is recommended. Therapy with Merozolyn should be titrated to gain an initial therapeutic response and to determine the minimal dose possible to maintain the desired therapeutic response. Usual dosages: for edema of cardiac failure, Metolazone 5 to 10 mg is given once daily. For edema of renal disease, Metolazone 5 to 20 mg is given once daily. Treatment of edematous states: the time interval for the initial dosage to show effect may vary; diuresis and saluresis usually begin within one hour and persist for 12 to 24 hours, depending on dosage. When a desired therapeutic effect has been obtained, it may be advisable to reduce the dose, if possible. The daily dose depends on the severity of the patient's condition, sodium intake and responsiveness. A decision to change the daily dose should be based upon the results of thorough clinical and laboratory determinations. If antihypertensive drugs or diuretics are given concurrently with Merozolyn, more careful dosage adjustment may be necessary. For patients with congestive cardiac failure who tend to experience paroxysmal nocturnal dyspnea, it is usually advisable to employ a dosage near the upper end of the range to ensure prolongation of diuresis and saluresis for a full 24 hour period. Hypertension: for mild to moderate essential hypertension, Metolazone 2.5 to 5 mg is given once daily. Treatment of hypertension: the time interval required for the initial dosage regimen of Metolazone to show effect may vary from three to four days, to three to six weeks, in the treatment of elevated blood pressure. Doses should be adjusted at appropriate intervals to achieve maximum therapeutic effect.

Side Effects & Interactions

Side Effects

No side-effect data recorded yet.