Hyzaar

Generic name: hydrochlorothiazide and losartan
Drug class: Angiotensin II inhibitors with thiazides

Medically reviewed by A Ras MD.

What is Hyzaar?

Hyzaar contains 2 prescription medicines, an angiotensin receptor blocker (ARB) and a diuretic (water pill). It is used to lower high blood pressure (hypertension). Hyzaar is not usually the first medicine used to treat high blood pressure.

It is also used to lower the chance of stroke in patients with high blood pressure and a heart problem called left ventricular hypertrophy (LVH). Hyzaar may not help Black patients with this problem.

Hyzaar has not been studied in children less than 18 years old.

High Blood Pressure (hypertension). Blood pressure is the force in your blood vessels when your heart beats and when your heart rests. You have high blood pressure when the force is too much. The losartan ingredient in Hyzaar can help your blood vessels relax so your blood pressure is lower. The hydrochlorothiazide ingredient in Hyzaar works by making your kidneys pass more water and salt.

Left Ventricular Hypertrophy (LVH) is an enlargement of the walls of the left chamber of the heart (the heart’s main pumping chamber). LVH can happen from several things. High blood pressure is the most common cause of LVH.

Description

HYZAAR 50/12.5 (losartan potassium-hydrochlorothiazide), HYZAAR 100/12.5 (losartan potassium-hydrochlorothiazide) and HYZAAR 100/25 (losartan potassium-hydrochlorothiazide) tablets combine an angiotensin II receptor blocker acting on the AT1 receptor subtype and a diuretic, hydrochlorothiazide.

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

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 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 50/12.5, 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.

Mechanism of Action

Losartan Potassium

Angiotensin II [formed from angiotensin I in a reaction catalyzed by angiotensin converting enzyme (ACE, kininase II)], is a potent vasoconstrictor, the primary vasoactive hormone of the renin-angiotensin system and an important component in the pathophysiology of hypertension. It also stimulates aldosterone secretion by the adrenal cortex. Losartan and its principal active metabolite block the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor found in many tissues (e.g., vascular smooth muscle, adrenal gland). There is also an AT2 receptor found in many tissues but it is not known to be associated with cardiovascular homeostasis.

Neither losartan nor its principal active metabolite exhibits any partial agonist activity at the AT1 receptor, and both have much greater affinity (about 1000-fold) for the AT1 receptor than for the AT2 receptor. In vitro binding studies indicate that losartan is a reversible, competitive inhibitor of the AT1 receptor. The active metabolite is 10 to 40 times more potent by weight than losartan and appears to be a reversible, non-competitive inhibitor of the AT1 receptor.

Neither losartan nor its active metabolite inhibits ACE (kininase II, the enzyme that converts angiotensin I to angiotensin II and degrades bradykinin), nor do they bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation.

Hydrochlorothiazide

Hydrochlorothiazide is a thiazide diuretic. Thiazides affect the renal tubular mechanisms of electrolyte reabsorption, directly increasing excretion of sodium and chloride in approximately equivalent amounts. Indirectly, the diuretic action of hydrochlorothiazide reduces plasma volume, with consequent increases in plasma renin activity, increases in aldosterone secretion, increases in urinary potassium loss, and decreases in serum potassium. The renin-aldosterone link is mediated by angiotensin II, so coadministration of an angiotensin II receptor antagonist tends to reverse the potassium loss associated with these diuretics. The mechanism of the antihypertensive effect of thiazides is unknown.

What is the most important information I should know about HYZAAR?

Hyzaar can cause harm or death to an unborn baby.
Talk to your doctor about other ways to lower your blood pressure if you plan to become pregnant.
If you get pregnant while taking Hyzaar tell your doctor right away.

Who should not take Hyzaar?

Do not take Hyzaar if you:

are allergic to any ingredients in Hyzaar. See a complete list of ingredients in Hyzaar at the end of this guide.
are not passing urine.
have diabetes and are taking a medicine called aliskiren to reduce blood pressure.

What should I tell my healthcare provider before taking Hyzaar?

Tell your doctor about all your medical conditions including if you:

are pregnant or planning to become pregnant. See “What is the most important information I should know about Hyzaar?”
are breastfeeding or plan to breastfeed. Hyzaar can pass into your milk and may harm your baby. You and your doctor should decide if you will take Hyzaar or breastfeed. You should not do both.
have been vomiting (throwing up), having diarrhea, sweating a lot, or not drinking enough fluids. These could cause you to have low blood pressure.
have liver problems
have kidney problems
have systemic lupus erythematosus (Lupus; SLE)
have diabetes
have gout
have any allergies

Tell your doctor about all of the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.

Hyzaar and certain other medicines may interact with each other. Especially tell your doctor if you are taking:

potassium supplements
salt substitutes containing potassium
other medicines that may increase serum potassium
water pills (diuretics)
lithium (a medicine used to treat a certain kind of depression)
medicines used to treat pain and arthritis, called non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 inhibitors
other medicines to reduce blood pressure.

Know the medicines you take. Keep a list of your medicines and show it to your doctor and pharmacist when you get a new medicine.

How should I take Hyzaar?

Take Hyzaar exactly as prescribed by your doctor. Your doctor may change your dose if needed.
Hyzaar can be taken with or without food.
If you miss a dose, take it as soon as you remember. If it is close to your next dose, do not take the missed dose. Just take the next dose at your regular time.
If you take too much Hyzaar, call your doctor or Poison Control Center, or go to the nearest hospital emergency room right away.
Your doctor may do blood tests from time to time while you are taking Hyzaar.

What are the possible side effects of Hyzaar?

Hyzaar may cause the following side effects that may be serious:

Injury or death of unborn babies. See “What is the most important information I should know about Hyzaar?”
Allergic reaction. Symptoms of an allergic reaction are swelling of the face, lips, throat, hives, or tongue. Get emergency medical help right away and stop taking Hyzaar.
Low blood pressure (hypotension). Low blood pressure may cause you to feel faint or dizzy. Lie down if you feel faint or dizzy. Call your doctor right away.
If you have kidney problems, you may see a worsening in how well your kidneys work. Call your doctor if you get swelling in your feet, ankles, or hands, or unexplained weight gain.
A new or worsening condition called systemic lupus erythematosus (Lupus; SLE)
Eye problems. One of the medicines in Hyzaar can cause eye problems that, if left untreated, may lead to vision loss. Symptoms of eye problems can happen within hours to weeks of starting Hyzaar. Tell your doctor right away if you have:
- decrease in vision
- eye pain

The most common side effects of Hyzaar in people with high blood pressure are:

“colds” (upper respiratory infection)
dizziness
stuffy nose
back pain

Tell your doctor if you get any side effect that bothers you or that won’t go away. This is not a complete list of side effects. For a complete list, ask your doctor or pharmacist.

General information about the safe and effective use of Hyzaar

Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use Hyzaar for a condition for which it was not prescribed. Do not give Hyzaar to other people, even if they have the same symptoms that you have. It may harm them.

This leaflet summarizes the most important information about Hyzaar. If you would like more information, talk with your doctor. You can ask your pharmacist or doctor for information that is written for health professionals.

How should I store Hyzaar?

Store Hyzaar at room temperature at 59°F to 86°F (15°C to 30°C).
Keep Hyzaar in a tightly closed container, and keep Hyzaar out of the light.
Keep Hyzaar and all medicines out of the reach of children.

What are the ingredients in Hyzaar?

Active ingredients: losartan potassium, hydrochlorothiazide

Inactive ingredients:

microcrystalline cellulose, lactose hydrous, pregelatinized starch, magnesium stearate, hydroxypropyl cellulose, hypromellose, titanium dioxide. Hyzaar 50/12.5 and Hyzaar 100/25 also contain D&C yellow No. 10 aluminum lake.

Hyzaar 50/12.5, Hyzaar 100/12.5, and Hyzaar 100/25 may also contain carnauba wax.

Label

PRINCIPAL DISPLAY PANEL – 50 MG/12.5 MG TABLET BOTTLE LABEL

NDC 78206-139-01
Hyzaar®
(Losartan Potassium and
Hydrochlorothiazide Tablets)
50 mg/12.5 mg
Each tablet contains 50 mg losartan potassium and
12.5 mg hydrochlorothiazide.
Store at 25°C (77°F); excursions permitted to 15-30°C
(59-86°F) [see USP Controlled Room Temperature].
Keep container tightly closed.
Protect from light.
Rx only
30 Tablets

PRINCIPAL DISPLAY PANEL – 100 MG/12.5 MG TABLET BOTTLE LABEL

NDC 78206-140-01
Hyzaar®
(Losartan Potassium and
Hydrochlorothiazide Tablets)
100 mg/12.5 mg
Each tablet contains 100 mg losartan potassium and
12.5 mg hydrochlorothiazide.
Store at 25°C (77°F); excursions permitted to 15-30°C
(59-86°F) [see USP Controlled Room Temperature].
Keep container tightly closed.
Protect from light.
Rx only
30 Tablets