No

Diuretic, Thiazide

Management of mild to moderate hypertension; treatment of edema in congestive heart failure and nephrotic syndrome, impaired renal function

B (per manufacturer); D (per expert analysis)

Hypersensitivity to metolazone or any component, or other thiazides, and sulfonamide derivatives; anuria; hepatic coma; pregnancy

Electrolyte disturbances (hypokalemia, hypochloremic alkalosis, hyponatremia) can occur. Use with caution in severe hepatic dysfunction; hepatic encephalopathy can be caused by electrolyte disturbances. Gout can be precipitate in certain patients with a history of gout, a familial predisposition to gout, or chronic renal failure. Cautious use in diabetics; may see a change in glucose control. Hypersensitivity reactions can occur. Can cause SLE exacerbation or activation. Use caution in severe renal impairment. Orthostatic hypotension may occur (potentiated by alcohol, barbiturates, narcotics, other antihypertensive drugs). Mykrox® tablets are not interchangeable with Zaroxyln® tablets. Use with caution in patients with moderate or high cholesterol concentrations. Photosensitization may occur.

>10%: Central nervousness: Dizziness

1% to 10%:

Cardiovascular: Orthostatic hypotension, palpitations, chest pain, cold extremities (rapidly acting), edema (rapidly acting), venous thrombosis (slow acting), syncope (slow acting)

Central nervous system: Headache, fatigue, lethargy, malaise, lassitude, anxiety, depression, nervousness, "weird" feeling (rapidly acting), chills (slow acting)

Endocrine & metabolic: Hypokalemia, impotence, reduced libido, excessive volume depletion (slow acting), hemoconcentration (slow acting), acute gouty attach (slow acting), weakness

Dermatologic: Rash, pruritus, dry skin (rapidly acting)

Gastrointestinal: Nausea, vomiting, abdominal pain, cramping, bloating, diarrhea or constipation, dry mouth

Genitourinary: Nocturia

Neuromuscular & skeletal: Muscle cramps, spasm

Ocular: Eye itching (rapidly acting)

Otic: Tinnitus (rapidly acting)

Respiratory: Cough (rapidly acting), epistaxis (rapidly acting), sinus congestion (rapidly acting), sore throat (rapidly acting),

<1% (Limited to important or life-threatening symptoms): Purpura, hyperglycemia, glycosuria, leukopenia, agranulocytosis, aplastic anemia, hepatitis

Symptoms of overdose include hypermotility, diuresis, lethargy, confusion, muscle weakness

Following GI decontamination, therapy is supportive with I.V. fluids, electrolytes, and I.V. pressors if needed

Angiotensin-converting enzyme inhibitors: Increased hypotension if aggressively diuresed with a thiazide-type diuretic.

Beta-blockers increase hyperglycemic effects in Type 2 diabetes mellitus.

Cyclosporine and thiazide- type compounds can increase the risk of gout or renal toxicity; avoid concurrent use.

Digoxin toxicity can be exacerbated if a diuretic induces hypokalemia or hypomagnesemia.

Lithium toxicity can occur due to a reduced renal excretion of lithium; monitor lithium concentration and adjust as needed.

Neuromuscular blocking agents effects may be prolonged; monitor serum potassium and neuromuscular status.

NSAIDs can decrease the efficacy of thiazide-type diuretics.

Inhibits sodium reabsorption in the distal tubules causing increased excretion of sodium and water, as well as, potassium and hydrogen ions

Same for all routes:

Duration: 12-24 hours

Absorption: Oral: Incomplete

Distribution: Crosses the placenta; appears in breast milk

Protein binding: 95%

Bioavailability: Mykrox® reportedly has highest

Half-life: 6-20 hours, renal function dependent

Elimination: Enterohepatic recycling; 80% to 95% excreted in urine

Adults: Oral:

Hypertension: 2.5-5 mg/dose every 24 hours

Hypertension (Mykrox®): 0.5 mg/day; if response is not adequate, increase dose to maximum of 1 mg/day

Dialysis: Not dialyzable (0% to 5%) via hemo- or peritoneal dialysis; supplemental dose is not necessary

This product may cause a potassium loss; your physician may prescribe a potassium supplement, another medication to help prevent the potassium loss, or recommend that you eat foods high in potassium, especially citrus fruits; do not change your diet on your own while taking this medication, especially if you are taking potassium supplements or medications to reduce potassium loss; too much potassium can be as harmful as too little; avoid natural licorice; should be administered after breakfast

Serum electrolytes (potassium, sodium, chloride, bicarbonate), renal function, blood pressure (standing, sitting/supine)

Metolazone is a potent diuretic and is often used in patients refractory to thiazide or loop diuretics. It is important that the patient be closely monitored to avoid profound volume depletion. Also watch for hypomagnesemia.

Dizziness is common; may cause drowsiness

May rarely cause agranulocytosis; use caution with clozapine and carbamazepine; may decrease lithium clearance resulting in an increase in serum lithium levels and potential lithium toxicity; monitor serum lithium levels

No information available to require special precautions

No effects or complications reported

Take exactly as directed - with meals. May take early in day to avoid nocturia. Include bananas or orange juice in daily diet but do not take dietary supplements without advice or consultation of prescriber. Do not use alcohol or OTC medication without consulting prescriber. Weigh weekly at the same time, in the same clothes. Report weight gain >5 lb/week. May cause dizziness or weakness (change position slowly when rising from sitting or lying, avoid driving or tasks requiring alertness until response to drug is known). You may experience nausea or loss of appetite (small frequent meals may help), impotence (reversible), constipation (fluids, exercise, dietary fiber may help), photosensitivity (use sunscreen, wear protective clothing and eyewear, and avoid direct sunlight). This medication does not replace other antihypertensive interventions; follow instructions for diet and lifestyle changes. Report flu-like symptoms, headache, joint soreness or weakness, difficulty breathing, skin rash, excessive fatigue, swelling of extremities, or difficulty breathing. Pregnancy/breast-feeding precautions: Do not get pregnant while taking this medication; use appropriate barrier contraceptive measures. Consult prescriber if breast-feeding.

Assess weight, I & O reports daily to determine fluid loss; take blood pressure with patient lying down and standing

Tablet:

Mykrox®: 0.5 mg

A 1 mg/mL suspension can be made by crushing twenty-four 5 mg tablets. Add a small amount of distilled water. Add 30 mL Cologel® and mix well. Add a sufficient amount of 2:1 simple syrup/cherry syrup mixture to make a final volume of 120 mL. Label "shake well". Stability is 2 weeks refrigerated.

Arnold WC, "Efficacy of Metolazone and Furosemide in Children With Furosemide-Resistant Edema," Pediatrics, 1984, 74(5):872-5.

Wells TG, "The Pharmacology and Therapeutics of Diuretics in the Pediatric Patient," Pediatr Clin North Am, 1990, 37(2):463-504.