MYKROX TABLETS ARE A RAPIDLY AVAILABLE FORMULATION OF METOLAZONE FOR ORAL ADMINISTRATION. MYKROX TABLETS AND OTHER FORMULATIONS OF METOLAZONE THAT SHARE ITS MORE RAPID AND COMPLETE BIOAVAILABILITY ARE NOT THERAPEUTICALLY EQUIVALENT TO ZAROXOLYN® TABLETS AND OTHER FORMULATIONS OF METOLAZONE THAT SHARE ITS SLOW AND INCOMPLETE BIOAVAILABILITY. FORMULATIONS BIOEQUIVALENT TO MYKROX AND FORMULATIONS BIOEQUIVALENT TO ZAROXOLYN SHOULD NOT BE INTERCHANGED FOR ONE ANOTHER.

MYKROX Tablets (metolazone tablets, USP) for oral administration contain ¹ / ₂ mg of metolazone, USP, a diuretic/saluretic/antihypertensive drug of the quinazoline class.

Metolazone has the molecular formula C ₁₆ H ₁₆ ClN ₃ O ₃ S,the chemical name 7-chloro-1,2,3,4-tetrahydro-2-methyl-3-(2-methylphenyl)-4-oxo-6-quinazolinesulfonamide, and a molecular weight of 365.83.

Metolazone is only sparingly soluble in water, but more soluble in plasma, blood, alkali and organic solvents.

Inactive Ingredients: Dibasic calcium phosphate, magnesium stearate, microcrystalline cellulose, pregelatinized starch, sodium starch glycolate.

MYKROX Tablets are indicated for the treatment of hypertension, alone or in combination with other antihypertensive drugs of a different class.

MYKROX TABLETS HAVE NOT BEEN EVALUATED FOR THE TREATMENT OF CONGESTIVE HEART FAILURE OR FLUID RETENTION DUE TO RENAL OR HEPATIC DISEASE AND THE CORRECT DOSAGE FOR THESE CONDITIONS AND OTHER EDEMA STATES HAS NOT BEEN ESTABLISHED.

SINCE A SAFE AND EFFECTIVE DIURETIC DOSE HAS NOT BEEN ESTABLISHED, MYKROX TABLETS SHOULD NOT BE USED WHEN DIURESIS IS DESIRED.

Usage in Pregnancy

The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no evidence that they are useful in the treatment of developed toxemia (see PRECAUTIONS ).

Edema during pregnancy may arise from pathologic causes or from the physiologic and mechanical consequences of pregnancy. MYKROX is not indicated for the treatment of edema in pregnancy. Dependent edema in pregnancy resulting from restriction of venous return by the expanded uterus is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy which is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort which is not relieved by rest. In these cases, a short course of diuretics may be appropriate.

Therapy should be individualized according to patient response.

For initial treatment of mild to moderate hypertension, the recommended dose is one MYKROX Tablet ( ¹ / ₂ mg) once daily, usually in the morning. If patients are inadequately controlled with one ¹ / ₂ mg tablet, the dose can be increased to two MYKROX Tablets (1 mg) once a day. An increase in hypokalemia may occur. Doses larger than 1 mg do not give increased effectiveness.

The same dose titration is necessary if MYKROX Tablets are to be substituted for other dosage forms of metolazone in the treatment of hypertension.

If blood pressure is not adequately controlled with two MYKROX Tablets alone, the dose should not be increased; rather, another antihypertensive agent with a different mechanism of action should be added to therapy with MYKROX Tablets.

MYKROX Tablets (metolazone tablets, USP), ¹ / ₂ mg are white, flat-faced, round tablets, debossed "MYKROX" on one side, and " ¹ / ₂ " on reverse side.

NDC 53014-847-71       Bottle of 100's

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [See USP Controlled Room Temperature]. Protect from light. Keep out of the reach of children.

MEDEVA PHARMACEUTICALS
Medeva Pharmaceuticals, Inc.
Rochester, NY 14623 USA
®Fisons Investments Inc.
© 1999, Medeva Pharmaceuticals, Inc.

Adverse experience information is available from more than 14 years of accumulated marketing experience with other formulations of metolazone for which reliable quantitative information is lacking and from controlled clinical trials with MYKROX from which incidences can be calculated.

In controlled clinical trials with MYKROX, adverse experiences resulted in discontinuation of therapy in 6.7-6.8% of patients given ¹ / ₂ to 1 mg of MYKROX.

Adverse experiences occurring in controlled clinical trials with MYKROX with an incidence of > 2%, whether or not considered drug-related, are summarized in the following table.

Some of the adverse effects reported in association with MYKROX also occur frequently in untreated hypertensive patients, such as headache and dizziness, which occurred in 14.8 and 7.4% of patients in a smaller parallel placebo group.

The following adverse effects were reported in less than 2% of the MYKROX treated patients.

Cardiovascular:   Cold extremities, edema, orthostatic hypotension, palpitations.

Central and Peripheral Nervous System:   Anxiety, depression, dry mouth, impotence, nervousness, neuropathy, weakness, "weird" feeling.

Dermatological:   Pruritus, rash, skin dryness.

Eyes, Ears, Nose, Throat:   Cough, epistaxis, eye itching, sinus congestion, sore throat, tinnitus.

Gastrointestinal:   Abdominal discomfort (pain, bloating), bitter taste, constipation, diarrhea, nausea, vomiting.

Genitourinary:   Nocturia.

Musculoskeletal:   Back pain.

Other Adverse Experiences:

Adverse experiences reported with other marketed metolazone formulations and most thiazide diuretics, for which quantitative data are not available, are listed in decreasing order of severity within body systems. Several are single or rare occurrences.

Cardiovascular:   excessive volume depletion, hemoconcentration, venous thrombosis.

Central and Peripheral Nervous System:   syncope, paresthesias, drowsiness, restlessness (sometimes resulting in insomnia).

Dermatologic/Hypersensitivity:   necrotizing angiitis (cutaneous vasculitis), purpura, dermatitis, photosensitivity, urticaria.

Gastrointestinal:   hepatitis, intrahepatic cholestatic jaundice, pancreatitis, anorexia.

Hematologic:   aplastic (hypoplastic) anemia, agranulocytosis, leukopenia.

Metabolic:   hypokalemia (see WARNINGS, Hypokalemia), hyponatremia, hyperuricemia, hypochloremia, hypochloremic alkalosis, hyperglycemia, glycosuria, increase in serum urea nitrogen (BUN) or creatinine, hypophosphatemia, hypomagnesemia, hypercalcemia.

Musculoskeletal:   acute gouty attacks.

Other:   transient blurred vision, chills.

In addition, rare adverse experiences reported in association with similar anti-hypertensive-diuretics but not reported to date for metolazone include: sialadenitis, xanthopsia, respiratory distress (including pneumonitis), thrombocytopenia, and anaphylactic reactions. These experiences could occur with clinical use of metolazone.

Diuretics

Furosemide and probably other loop diuretics given concomitantly with metolazone can cause unusually large or prolonged losses of fluid and electrolytes (see WARNINGS).

Other Antihypertensives

When MYKROX Tablets are used with other antihypertensive drugs, care must be taken, especially during initial therapy. Dosage adjustments of other antihypertensives may be necessary.

Alcohol, Barbiturates, and Narcotics

The hypotensive effects of these drugs may be potentiated by the volume contraction that may be associated with metolazone therapy.

Digitalis Glycosides

Diuretic-induced hypokalemia can increase the sensitivity of the myocardium to digitalis. Serious arrhythmias can result.

Corticosteroids or ACTH

May increase the risk of hypokalemia and increase salt and water retention.

Lithium

Serum lithium levels may increase (see WARNINGS).

Curariform Drugs

Diuretic-induced hypokalemia may enhance neuromuscular blocking effects of curariform drugs (such as tubocurarine) the most serious effect would be respiratory depression which could proceed to apnea. Accordingly, it may be advisable to discontinue MYKROX Tablets three days before elective surgery.

Salicylates and Other Non-Steroidal Anti-Inflammatory Drugs

May decrease the antihypertensive effects of MYKROX Tablets.

Sympathomimetics

Metolazone may decrease arterial responsiveness to norepinephrine, but this diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use.

Insulin and Oral Antidiabetic Agents

See Glucose Tolerance under PRECAUTIONS, GENERAL.

Methenamine

Efficacy may be decreased due to urinary alkalizing effect of metolazone.

Anticoagulants

Metolazone, as well as other thiazide-like diuretics, may affect the hypoprothrombinemic response to anticoagulants; dosage adjustments may be necessary.

Rapid Onset Hyponatremia

Rarely, the rapid onset of severe hyponatremia and/or hypokalemia has been reported following initial doses of thiazide and non-thiazide diuretics. When symptoms consistent with severe electrolyte imbalance appear rapidly, drug should be discontinued and supportive measures should be initiated immediately. Parenteral electrolytes may be required. Appropriateness of therapy with this class of drugs should be carefully reevaluated.

Hypokalemia

Hypokalemia may occur, with consequent weakness, cramps, and cardiac dysrhythmias. Serum potassium should be determined at regular intervals, and dose reduction, potassium supplementation or addition of a potassium sparing diuretic instituted whenever indicated. Hypokalemia is a particular hazard in patients who are digitalized or who have or have had a ventricular arrhythmia; dangerous or fatal arrhythmias may be precipitated. Hypokalemia is dose related.

In controlled clinical trials, 1.5% of patients taking ¹ / ₂ mg and 3.1% of patients taking 1 mg of MYKROX daily developed clinical hypokalemia (defined as hypokalemia accompanied by signs or symptoms); 21% of the patients taking ¹ / ₂ mg and 30% of the patients taking 1 mg of MYKROX daily developed hypokalemia (defined as a serum potassium concentration below 3.5 mEq/L); in another controlled clinical trial in which the patients started therapy with a serum potassium level greater than 4.0 mEq/L, 8% of patients taking ¹ / ₂ mg of MYKROX daily developed hypokalemia (defined as a serum potassium concentration below 3.5 mEq/L).

Concomitant Therapy

Lithium

In general, diuretics should not be given concomitantly with lithium because they reduce its renal clearance and add a high risk of lithium toxicity. Read prescribing information for lithium preparations before use of such concomitant therapy.

Furosemide:   Unusually large or prolonged losses of fluids and electrolytes may result when metolazone is administered concomitantly to patients receiving furosemide (see

PRECAUTIONS

Other Antihypertensive Drugs:   When MYKROX Tablets are used with other antihypertensive drugs, particular care must be taken to avoid excessive reduction of blood pressure, especially during initial therapy.

Cross-Allergy

Cross-allergy, while not reported to date, theoretically may occur when MYKROX Tablets are given to patients known to be allergic to sulfonamide-derived drugs, thiazides, or quinethazone.

Sensitivity Reactions

Sensitivity reactions (e.g., angioedema, bronchospasm) may occur with or without a history of allergy or bronchial asthma and may occur with the first dose of MYKROX.

DO NOT INTERCHANGE

MYKROX TABLETS ARE A RAPIDLY AVAILABLE FORMULATION OF METOLAZONE FOR ORAL ADMINISTRATION. MYKROX TABLETS AND OTHER FORMULATIONS OF METOLAZONE THAT SHARE ITS MORE RAPID AND COMPLETE BIOAVAILABILITY ARE NOT THERAPEUTICALLY EQUIVALENT TO ZAROXOLYN TABLETS AND OTHER FORMULATIONS OF METOLAZONE THAT SHARE ITS SLOW AND INCOMPLETE BIOAVAILABILITY. FORMULATIONS BIOEQUIVALENT TO MYKROX AND FORMULATIONS BIOEQUIVALENT TO ZAROXOLYN SHOULD NOT BE INTERCHANGED FOR ONE ANOTHER.

GENERAL:

Fluid and Electrolytes

All patients receiving therapy with MYKROX Tablets should have serum electrolyte measurements done at appropriate intervals and be observed for clinical signs of fluid and/or electrolyte imbalance: namely, hyponatremia, hypochloremic alkalosis, and hypokalemia. In patients with severe edema accompanying cardiac failure or renal disease, a low-salt syndrome may be produced, especially with hot weather and a low-salt diet. Serum and urine electrolyte determinations are particularly important when the patient has protracted vomiting, severe diarrhea, or is receiving parenteral fluids. Warning signs of imbalance are: dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscle fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting. Hyponatremia may occur at any time during long term therapy and, on rare occasions, may be life threatening.

The risk of hypokalemia is increased when larger doses are used, when diuresis is rapid, when severe liver disease is present, when corticosteroids are given concomitantly, when oral intake is inadequate or when excess potassium is being lost extrarenally, such as with vomiting or diarrhea.

Thiazide-like diuretics have been shown to increase the urinary excretion of magnesium; this may result in hypomagnesemia.

Glucose Tolerance

Metolazone may raise blood glucose concentrations possibly causing hyperglycemia and glycosuria in patients with diabetes or latent diabetes.

Hyperuricemia

MYKROX regularly causes an increase in serum uric acid and can occasionally precipitate gouty attacks even in patients without a prior history of them.

Azotemia

Azotemia, presumably prerenal azotemia, may be precipitated during the administration of MYKROX Tablets. If azotemia and oliguria worsen during treatment of patients with severe renal disease, MYKROX Tablets should be discontinued.

Renal Impairment

Use caution when administering MYKROX Tablets to patients with severely impaired renal function. As most of the drug is excreted by the renal route, accumulation may occur.

Orthostatic Hypotension

Orthostatic hypotension may occur; this may be potentiated by alcohol, barbiturates, narcotics, or concurrent therapy with other antihypertensive drugs. In controlled clinical trials, 1.4% of patients treated with MYKROX Tablets ( ¹ / ₂ mg) had orthostatic hypotension; this effect was not reported in the placebo group.

Hypercalcemia

Hypercalcemia may infrequently occur with metolazone, especially in patients taking high doses of vitamin D or with high bone turnover states, and may signify hidden hyperparathyroidism. Metolazone should be discontinued before tests for parathyroid function are performed.

Systemic Lupus Erythematosus

Thiazide diuretics have exacerbated or activated systemic lupus erythematosus and this possibility should be considered with MYKROX Tablets.

INFORMATION FOR PATIENTS:   Patients should be informed of possible adverse effects, advised to take the medication as directed and promptly report any possible adverse reactions to the treating physician.

DRUG INTERACTIONS:

Diuretics

Furosemide and probably other loop diuretics given concomitantly with metolazone can cause unusually large or prolonged losses of fluid and electrolytes (see

WARNINGS

Other Antihypertensives

When MYKROX Tablets are used with other antihypertensive drugs, care must be taken, especially during initial therapy. Dosage adjustments of other antihypertensives may be necessary.

Alcohol, Barbiturates, and Narcotics

The hypotensive effects of these drugs may be potentiated by the volume contraction that may be associated with metolazone therapy.

Digitalis Glycosides

Diuretic-induced hypokalemia can increase the sensitivity of the myocardium to digitalis. Serious arrhythmias can result.

Corticosteroids or ACTH

May increase the risk of hypokalemia and increase salt and water retention.

Lithium

Serum lithium levels may increase (see

WARNINGS

Curariform Drugs

Diuretic-induced hypokalemia may enhance neuromuscular blocking effects of curariform drugs (such as tubocurarine) the most serious effect would be respiratory depression which could proceed to apnea. Accordingly, it may be advisable to discontinue MYKROX Tablets three days before elective surgery.

Salicylates and Other Non-Steroidal Anti-Inflammatory Drugs

May decrease the antihypertensive effects of MYKROX Tablets.

Sympathomimetics

Metolazone may decrease arterial responsiveness to norepinephrine, but this diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use.

Insulin and Oral Antidiabetic Agents

See Glucose Tolerance under

PRECAUTIONS

Methenamine

Efficacy may be decreased due to urinary alkalizing effect of metolazone.

Anticoagulants

Metolazone, as well as other thiazide-like diuretics, may affect the hypoprothrombinemic response to anticoagulants; dosage adjustments may be necessary.

DRUG/LABORATORY TEST INTERACTIONS:   None reported.

CARCINOGENESIS, MUTAGENESIS, IMPAIRMENT OF FERTILITY:   Mice and rats administered metolazone 5 days/week for up to 18 and 24 months, respectively, at daily doses of 2, 10 and 50 mg/kg, exhibited no evidence of a tumorigenic effect of the drug. The small number of animals examined histologically and poor survival in the mice limit the conclusions that can be reached from these studies.

Metolazone was not mutagenic in vitro in the Ames Test using Salmonella typhimurium strains TA-97, TA-98, TA-100, TA-102 and TA-1535.

Reproductive performance has been evaluated in mice and rats. There is no evidence that metolazone possesses the potential for altering reproductive capacity in mice. In a rat study, in which males were treated orally with metolazone at doses of 2, 10 and 50 mg/kg for 127 days prior to mating with untreated females, an increased number of resorption sites was observed in dams mated with males from the 50 mg/kg group. In addition, the birth weight of offspring was decreased and the pregnancy rate was reduced in dams mated with males from the 10 and 50 mg/kg groups.

PREGNANCY

Teratogenic Effects Pregnancy Category B.

Reproduction studies performed in mice, rabbits and rats treated during the appropriate periods of gestation at doses up to 50 mg/kg/day have revealed no evidence of harm to the fetus due to metolazone. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, MYKROX Tablets should be used during pregnancy only if clearly needed. Metolazone crosses the placental barrier and appears in cord blood.

Non-Teratogenic Effects

The use of MYKROX Tablets in pregnant women requires that the anticipated benefit be weighed against possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions which have occurred in the adult. It is not known what effect the use of the drug during pregnancy has on the later growth, development and functional maturation of the child. No such effects have been reported with metolazone.

LABOR AND DELIVERY:   Based on clinical studies in which women received metolazone in late pregnancy until the time of delivery, there is no evidence that the drug has any adverse effects on the normal course of labor or delivery.

NURSING MOTHERS:   Metolazone appears in breast milk. Because of the potential for serious adverse reactions in nursing infants from metolazone, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

PEDIATRIC USE:   Safety and effectiveness of MYKROX Tablets in pediatric patients have not been established, and such use is not recommended.

Intentional overdosage has been reported rarely with metolazone and similar diuretic drugs.

Signs and Symptoms

Orthostatic hypotension, dizziness, drowsiness, syncope, electrolyte abnormalities, hemoconcentration and hemodynamic changes due to plasma volume depletion may occur. In some instances depressed respiration may be observed. At high doses, lethargy of varying degree may progress to coma within a few hours. The mechanism of CNS depression with thiazide overdosage is unknown. Also, GI irritation and hypermotility may occur. Temporary elevation of BUN has been reported, especially in patients with impairment of renal function. Serum electrolyte changes and cardiovascular and renal function should be closely monitored.

Treatment

There is no specific antidote available but immediate evacuation of stomach contents is advised. Dialysis is not likely to be effective. Care should be taken when evacuating the gastric contents to prevent aspiration, especially in the stuporous or comatose patient. Supportive measures should be initiated as required to maintain hydration, electrolyte balance, respiration and cardiovascular and renal function.

Anuria, hepatic coma or precoma, known allergy or hypersensitivity to metolazone.

MYKROX (metolazone) is a quinazoline diuretic, with properties generally similar to the thiazide diuretics. The actions of MYKROX result from interference with the renal tubular mechanism of electrolyte reabsorption. MYKROX 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. MYKROX does not inhibit carbonic anhydrase. A proximal action of metolazone 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. This action has been demonstrated in animals by micropuncture studies.

The antihypertensive mechanism of action of metolazone is not fully understood but is presumed to be related to its saluretic and diuretic properties.

In two double-blind, controlled clinical trials of MYKROX Tablets, the maximum effect on mean blood pressure was achieved within 2 weeks of treatment and showed some evidence of an increased response at 1 mg compared to ¹ / ₂ mg. There was no indication of an increased response with 2 mg.

After six weeks of treatment, the mean fall in serum potassium was 0.42 mEq/L at ¹ / ₂ mg, 0.66 mEq/L at 1 mg and 0.7 mEq/L at 2 mg. Serum uric acid increased by 1.1 to 1.4 mg/dL at increasing doses. There were small falls in serum sodium and chloride and a 1.3-2.1 mg/dL increase in BUN at increasing doses.

The rate and extent of absorption of metolazone from MYKROX Tablets were equivalent to those from an oral solution of metolazone. Peak blood levels are obtained within 2 to 4 hours of oral administration with an elimination half-life of approximately 14 hours. MYKROX Tablets have been shown to produce blood levels that are dose proportional between ¹ / ₂  -2 mg. Steady state blood levels are usually reached in 4-5 days.

In contrast, other formulations of metolazone produce peak blood concentrations approximately 8 hours following oral administration; absorption continues for an additional 12 hours.

Patients should be informed of possible adverse effects, advised to take the medication as directed and promptly report any possible adverse reactions to the treating physician.

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

METOLAZONE - ORAL

(me-TOLE-a-zone)

COMMON BRAND NAME(S): Zaroxolyn

USES: Metolazone is a "water pill" (diuretic) that increases the amount of urine you make, which causes your body to get rid of excess water. This drug is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems.

This medication also reduces swelling/fluid retention (edema) which can result from conditions such as congestive heart failure or kidney disease. This can help to improve symptoms such as trouble breathing.

HOW TO USE: Take this medication by mouth with or without food, usually once daily, or as directed by your doctor. The dosage is based on your medical condition and response to therapy.

If you take this drug too close to bedtime, you may need to wake up to urinate. Therefore, it is best to take this medication at least 4 hours before your bedtime.

Use this medication regularly in order to get the most benefit from it. Remember to use it at the same time each day as directed. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick. Do not stop taking this medication without consulting your doctor. It may take up to 3-6 weeks to see a lowering of your blood pressure.

Cholestyramine and colestipol can decrease the absorption of metolazone. If you are taking either of these drugs, separate metolazone from cholestyramine by at least 4 hours and from colestipol by at least 2 hours.

If your condition persists or worsens, contact your doctor or pharmacist.

SIDE EFFECTS: Dizziness, lightheadedness, headache, blurred vision, loss of appetite, stomach upset, diarrhea, or constipation may occur as your body adjusts to the medication. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may lead to excessive loss of body water and minerals (including potassium). Tell your doctor immediately if you have any of these unlikely but serious symptoms of dehydration or mineral loss: muscle cramps or weakness, confusion, severe dizziness, unusual dry mouth or thirst, nausea or vomiting, fast/irregular heartbeat, unusual decrease in the amount of urine, fainting, seizures.

Tell your doctor immediately if any of these unlikely but serious side effects occur: numbness/tingling of the arms/legs, decreased sexual ability.

Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: persistent sore throat or fever, easy bleeding or bruising, stomach/abdominal pain, persistent nausea/vomiting, yellowing of eyes/skin.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching, swelling, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking metolazone, tell your doctor or pharmacist if you are allergic to it; or to sulfa medications; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: severe kidney disease (inability to make urine or anuria).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease, untreated mineral imbalance (e.g., sodium, potassium), gout, lupus.

If you have diabetes, metolazone may affect your blood sugar levels. Check your blood sugar levels regularly as directed and share the results with your doctor. Tell your doctor immediately if you have symptoms of high blood sugar such as increased thirst/urination. Your doctor may need to adjust your anti-diabetic medication or diet.

This drug may reduce the potassium levels in your blood. Ask your doctor about adding potassium to your diet. A potassium supplement may be prescribed by your doctor.

This medication may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths or sunlamps. Use a sunscreen and wear protective clothing when outdoors.

Before having surgery, tell your doctor or dentist that you are taking this medication.

This drug may make you dizzy or cause blurred vision; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages.

To minimize dizziness and lightheadedness, get up slowly when rising from a seated or lying position.

Caution is advised when using this drug in the elderly because they may be more sensitive to its effects, especially dizziness.

Metolazone should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

This drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

See also the How to Use section.

This drug should not be used with the following medications because very serious interactions may occur: cisapride.

If you are currently using any of these medications, tell your doctor or pharmacist before starting metolazone.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: cholestyramine, colestipol, corticosteroids (e.g., prednisone), diazoxide, digoxin, lithium, nonsteroidal anti-inflammatory drugs (e.g., ibuprofen, indomethacin).

Check the labels on all your medicines (e.g., cough-and-cold products, diet aids) because they may contain ingredients that could increase your blood pressure. Ask your pharmacist about the safe use of those products.

This product can affect the results of certain lab tests (e.g., parathyroid function tests). Make sure laboratory personnel and your doctors know you use this drug.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include fainting, severe weakness, a severe decrease in amount of urine, or slow or shallow breathing.

NOTES: Do not share this medication with others. Lifestyle changes such as stress reduction programs, exercise, and dietary changes may increase the effectiveness of this medicine. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.

Laboratory and/or medical tests (e.g., blood mineral levels such as potassium, kidney and liver function tests, cholesterol level) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Have your blood pressure checked regularly while taking this medication. Discuss with your doctor how to monitor your own blood pressure.

MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE: Store at room temperature (77 degrees F or 25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

MEDICAL ALERT: Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).

Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.