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Medications and Drugs

Brand Names: Zaroxolyn

Generic Name: metolazone (Pronunciation: me TOL a zone)

What is metolazone (Zaroxolyn)?

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).

Metolazone may also be used for other purposes not listed in this medication guide.

Metolazone 10 mg-EON

oval, yellow, imprinted with E 56

Metolazone 10 mg-MYL

round, green, imprinted with M, 174

Metolazone 10 mg-UPS

round, peach, imprinted with 645, 10

Metolazone 2.5 mg-EON

oval, pink, imprinted with E 50

Metolazone 2.5 mg-MYL

round, white, imprinted with M, 172

Metolazone 2.5 mg-UPS

round, pink, imprinted with 2 1/2, 643

Metolazone 5 mg-EON

oval, blue, imprinted with E 55

Metolazone 5 mg-MYL

round, peach, imprinted with M, 173

Metolazone 5 mg-UPS

round, blue, imprinted with 644, 5

Zaroxolyn 10 mg

round, yellow, imprinted with ZAROXOLYN, 10

Zaroxolyn 2.5 mg

round, pink, imprinted with ZAROXOLYN, 2 1/2

Zaroxolyn 5 mg

round, blue, imprinted with ZAROXOLYN, 5

What are the possible side effects of metolazone (Zaroxolyn)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have a serious side effect such as:

  • dry mouth, thirst, nausea, vomiting;
  • feeling weak, drowsy, restless, or light-headed;
  • fast or uneven heartbeat;
  • muscle pain or weakness;
  • chest pain;
  • urinating less than usual or not at all; or
  • numbness or tingly feeling.

Less serious side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about metolazone (Zaroxolyn)?

Do not use this medication if you are unable to urinate, or if you have severe liver disease.

Before using this medication, tell your doctor if you have liver disease, kidney disease, asthma, allergies, gout, diabetes, or an allergy to sulfa drugs.

Avoid drinking alcohol, which can increase some of the side effects of metolazone.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

There are many other medicines that can interact with metolazone. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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