Hyzaar (Losartan Potassium-Hydrochlorothiazide) Drug Information: Description, User Reviews, Drug Side Effects, Interactions

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May 26, 2012

Hyzaar

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Hyzaar

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HYZAAR® 50-12.5
(losartan potassium-hydrochlorothiazide) Tablets

HYZAAR® 100-12.5
(losartan potassium-hydrochlorothiazide) Tablets

HYZAAR® 100-25
(losartan potassium-hydrochlorothiazide) Tablets

USE IN PREGNANCY

When used in pregnancy during the second and third trimesters, drugs that act directly on the renin-angiotensin system can cause injury and even death to the developing fetus. When pregnancy is detected, HYZAAR should be discontinued as soon as possible. See WARNINGS, Fetal/Neonatal Morbidity and Mortality.

DRUG DESCRIPTION

HYZAAR® 50-12.5 (losartan potassium-hydrochlorothiazide), HYZAAR® 100-12.5 (losartan potassium-hydrochlorothiazide) and HYZAAR® 100-25 (losartan potassium-hydrochlorothiazide) combine an angiotensin II receptor (type AT₁) antagonist and a diuretic, hydrochlorothiazide.

Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-[p-(o-1Htetrazol-5-ylphenyl)benzyl]imidazole-5-methanol monopotassium salt. Its empirical formula is C₂₂H₂₂ClKN₆O, and its structural formula is:

Losartan potassium Structural Formula Illustration

Losartan potassium is a white to off-white free-flowing crystalline powder with a molecular weight of 461.01. It is freely soluble in water, soluble in alcohols, and slightly soluble in common organic solvents, such as acetonitrile and methyl ethyl ketone.

Oxidation of the 5-hydroxymethyl group on the imidazole ring results in the active metabolite of losartan.

Hydrochlorothiazide is 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C₇H₈ClN₃O₄S₂ and its structural formula is:

Hydrochlorothiazide Structural Formula Illustration

Hydrochlorothiazide is a white, or practically white, crystalline powder with a molecular weight of 297.74, which is slightly soluble in water, but freely soluble in sodium hydroxide solution.

HYZAAR is available for oral administration in three tablet combinations of losartan and hydrochlorothiazide. HYZAAR 50-12.5 contains 50 mg of losartan potassium and 12.5 mg of hydrochlorothiazide. HYZAAR 100-12.5 contains 100 mg of losartan potassium and 12.5 mg of hydrochlorothiazide. HYZAAR 100-25 contains 100 mg of losartan potassium and 25 mg of hydrochlorothiazide. Inactive ingredients are microcrystalline cellulose, lactose hydrous, pregelatinized starch, magnesium stearate, hydroxypropyl cellulose, hypromellose, and titanium dioxide. HYZAAR 50-12.5 and HYZAAR 100-25 also contain D&C yellow No. 10 aluminum lake. HYZAAR 5012.5, HYZAAR 100-12.5, and HYZAAR 100-25 may also contain carnauba wax.

HYZAAR 50-12.5 contains 4.24 mg (0.108 mEq) of potassium, HYZAAR 100-12.5 contains 8.48 mg (0.216 mEq) of potassium, and HYZAAR 100-25 contains 8.48 mg (0.216 mEq) of potassium.

What are the possible side effects of hydrochlorothiazide and losartan (Hyzaar)?

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.

In rare cases, hydrochlorothiazide and losartan 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 muscle pain, tenderness, or weakness especially if you also have fever, nausea or vomiting, and dark colored urine.

Stop using this medication and call your doctor at...

Read All Potential Side Effects and See Pictures of Hyzaar »

What are the precautions when taking losartan potassium-hydrochlorothiazide (Hyzaar)?

Before taking this medication, tell your doctor or pharmacist if you are allergic to losartan or hydrochlorothiazide; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: gout, kidney disease, liver disease, lupus.

This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Severe sweating, diarrhea, or vomiting can increase the risk for lightheadedness or a serious loss of body water (dehydration). Report prolonged...

Read All Potential Precautions of Hyzaar »

Last reviewed on RxList: 12/6/2011
This monograph has been modified to include the generic and brand name in many instances.