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Hyzaar

Generic name: hydrochlorothiazide and losartanHYE-droe-KLOR-oh-THYE-a-zide-and-loe-SAR-tan ]
Drug class: Angiotensin II inhibitors with thiazides

Medically reviewed by Philip Thornton, DipPharm. Last updated on Feb 19, 2024.

What is Hyzaar?

Hyzaar contains a combination of hydrochlorothiazide and losartan. Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention.

Losartan is an angiotensin II receptor antagonist (sometimes called an ARB blocker). Losartan keeps blood vessels from narrowing, which lowers blood pressure and improves blood flow.

Hyzaar is used to treat high blood pressure (hypertension).

Hyzaar is also used to lower the risk of stroke in certain people with heart disease.

Warnings

Do not use Hyzaar if you are pregnant. Stop using the medicine and tell your doctor right away if you become pregnant.

You should not use this medicine if you are unable to urinate.

If you have diabetes, do not use Hyzaar together with any medication that contains aliskiren (a blood pressure medicine).

You may also need to avoid taking Hyzaar with aliskiren if you have kidney disease.

In rare cases, Hyzaar can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. Call your doctor right away if you have unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, and dark colored urine.

Before taking this medicine

You should not use Hyzaar if you are allergic to hydrochlorothiazide or losartan, if you are unable to urinate.

To make sure Hyzaar is safe for you, tell your doctor if you have ever had:

Do not use if Hyzaar you are pregnant. Stop using the medicine and tell your doctor right away if you become pregnant. Hydrochlorothiazide and losartan can cause injury or death to the unborn baby if you take the medicine during your second or third trimester.

You should not breast-feed while using this medicine.

How should I take Hyzaar?

Take Hyzaar exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Your blood pressure will need to be checked often.

Call your doctor if you are sick with vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while taking this medicine. This can lead to very low blood pressure, a serious electrolyte imbalance, or kidney failure.

If you need surgery or medical tests, tell the surgeon ahead of time that you are using Hyzaar.

If you have high blood pressure, keep using Hyzaar even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medicine for the rest of your life.

Store at room temperature away from moisture, heat, and light.

Dosing information

Usual Adult Dose for Hypertension:

HYPERTENSION:
Hydrochlorothiazide 12.5 to 25 mg-Losartan 50 to 100 mg orally once a day

Maximum dose: Hydrochlorothiazide 25 mg-Losartan 100 mg orally once a day

Comments:
-A patient whose blood pressure is not adequately controlled with hydrochlorothiazide or losartan monotherapy may be switched to hydrochlorothiazide 12.5 mg-losartan 50 mg orally once a day.
-May increase dose if blood pressure remains uncontrolled after about 3 weeks.

Use: Treatment of hypertension. This drug is not indicated for initial therapy except when hypertension is severe enough that the benefit of achieving prompt blood pressure control exceeds the risk of initiating combination therapy.

SEVERE HYPERTENSION:
Initial treatment: Hydrochlorothiazide 12.5 mg-Losartan 50 mg orally once a day; if blood pressure remains uncontrolled after 2 to 4 weeks, may initiate maximum dose.

Maximum dose: Hydrochlorothiazide 25 mg-Losartan 100 mg orally once a day

HYPERTENSION WITH LEFT VENTRICULAR HYPERTROPHY:
Initial therapy: Losartan monotherapy; if blood pressure remains uncontrolled, may initiate this drug.

Add-on therapy: Hydrochlorothiazide 12.5 mg-Losartan 50 mg orally once a day; if blood pressure remains uncontrolled, initiate hydrochlorothiazide 12.5 mg-losartan 100 mg orally once a day, followed by hydrochlorothiazide 25 mg-losartan 100 mg orally once a day, if needed.

Use: To reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy, but there is evidence that this benefit does not apply to Black patients.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Hydrochlorothiazide may increase your risk of skin cancer. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors. Your doctor may want you to have skin examinations on a regular basis.

Do not use potassium supplements or salt substitutes, unless your doctor has told you to.

Drinking alcohol can further lower your blood pressure and may cause side effects.

Avoid becoming overheated or dehydrated during exercise, in hot weather, or by not drinking enough fluids.

Hyzaar side effects

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

Call your doctor at once if you have:

Common Hyzaar 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.

What other drugs will affect Hyzaar?

If you also take cholestyramine or colestipol, take your Hyzaar dose 4 hours before or 4 to 6 hours after you take the other medicine.

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with hydrochlorothiazide and losartan, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Hyzaar only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.