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Hydrochlorothiazide and losartan

Generic name: hydrochlorothiazide and losartan [HYE-droe-KLOR-oh-THYE-a-zide-and-loe-SAR-tan]
Brand name: Hyzaar
Oral tablet: (12.5 mg–50 mg; 25 mg–100 mg; 12.5 mg–100 mg)
Drug class: thiazide-containing angiotensin II inhibitors

What is Hydrochlorothiazide and losartan?

Hydrochlorothiazide works as a diuretic. Losartan works as an antagonist of the angiotensin-II receptor (also called an ARB blocker).Combination medicine Hydrochlorothiazide (Losartan) is used to treat hypertension. It can also be used to reduce the risk of stroke for certain people who have heart diseases.This medication guide does not list all possible uses for hydrochlorothiazide or losartan.

Side effects of Hydrochlorothiazide and losartan

If you experience any of the following signs and symptoms of an allergic reaction: hives, difficulty breathing or swelling in your lips, face, tongue or throat. Seek medical assistance immediately.

Losartan and hydrochlorothiazide can cause serious side effects. If you experience:

  • A feeling of lightheadedness, as if you could pass out.
  • Heartbeats irregular;
  • Eye pain and vision problems
  • Kidney problems: rapid weight gain or swelling of the hands, feet, or ankles; little or no urine;
  • If you have new or worsening symptoms, such as joint pain or a skin rash that gets worse in the sun on your arms or cheeks,
  • Signs of electrolyte depletion include increased thirst or urination; confusion; nausea; constipation; and muscular pain. Other symptoms are leg cramps, leg pain, muscle cramps, leg cramps or numbness, severe weakness, or tingling.

Some of the common side effects associated with hydrochlorothiazide or losartan include:

  • Dizziness;
  • Backache
  • Cold symptoms may include stuffy nose and sneezing.

There may be other side effects. For medical advice regarding any side effects, contact your physician; alternatively, the FDA can be reached at 1-800-FDA-1088 in order to report side effects.


If you can't urinate, don't use hydrochlorothiazide or losartan.Use it only if you're not pregnant. If you become pregnant, stop using the medication and immediately tell your doctor.Do not take hydrochlorothiazide or losartan if you have diabetes with any medicine that contains aliskiren.

Before you take this drug

This medicine should not be used if you have an allergy to hydrochlorothiazide, losartan, or if you cannot urinate.Do not take hydrochlorothiazide or losartan with aliskiren, a blood pressure medication, if you have diabetes.If you have kidney problems, you may need to avoid using hydrochlorothiazide or losartan in conjunction with aliskiren.

Inform your physician of any of the following issues:

  • Lupus;
  • Liver or kidney disease
  • Allergies or asthma
  • Diabetes;
  • Gout;
  • Congestive heart failure;
  • Glaucoma;
  • Your blood potassium levels could either be low or high.
  • High cholesterol or triglyceride levels
  • An allergy is a reaction to penicillin or sulfa drugs.

If you are pregnant, do not take this medication. If you are pregnant, stop using the medication and call your doctor immediately.This medicine should not be used while breastfeeding.Anyone younger than 18 is not allowed to use hydrochlorothiazide or losartan.

How to take hydrochlorothiazide and losartan?

Read all the instructions or guides that come with your medication and follow the directions. Sometimes, your doctor will change the dose. You must take the medication exactly as prescribed.You will need to check your blood pressure often.If you have diarrhea or vomiting or are perspiring, call your doctor. It is easy to become dehydrated when taking hydrochlorothiazide with losartan. This can cause very low blood pressure or a serious electrolyte imbalance, as well as renal failure.Tell your doctor if you plan to undergo surgery or any medical tests that you will be taking hydrochlorothiazide.Even if you are feeling well, continue to take this medication if you have high blood pressure. High blood pressure is often asymptomatic. Blood pressure medication may be needed for the rest of your life.Store away from moisture, heat, and light at room temperature.

Details on dosage

Usual Adult Dose for Hypertension:

Losartan 50–100 mg, orally, once per day. Hydrochlorothiazide 12.5–25 mg
Maximum dose: hydrochlorothiazide 25 mg; losartan 100 mg orally, once per day.
If hydrochlorothiazide and losartan alone are not controlling blood pressure, the patient may be switched to hydrochlorothiazide (12.25 mg) and losartan (50 mg) orally, once daily.
If blood pressure is not controlled after 3 weeks, you may need to increase the dose.
Hypertension. This drug is not recommended for the first treatment of hypertension unless the severity of the condition is such that the benefits of rapid blood pressure control outweigh the risks of starting combination therapy.
Initial treatment: hydrochlorothiazide 12.5, losartan 50 mg orally, once daily. If blood pressure is not controlled after 2 to 4 weeks, you may increase the dose.
Maximum dose: hydrochlorothiazide 25 mg; losartan 100 mg orally, once per day.
Initial therapy: Losartan as a monotherapy. If blood pressure is not controlled, this drug may be initiated.
Add-on Therapy: Hydrochlorothiazide 12.5 mg and Losartan 50 mg orally, once daily. If blood pressure is not controlled, start hydrochlorothiazide (12.25 mg), then 100mg of losartan orally, once daily.
Use: Reduce the risk of stroke for patients with left ventricular hypertrophy and hypertension. However, there are indications that this benefit is not applicable to black patients.

What happens if I miss the dose?

If you are almost due for your next dose, skip the missed one. Never take two doses of the same medicine at once.

What happens if I overdose?

Contact the Poison Control Hotline immediately on 1-800-222-1222 if you suspect poison exposure, or seek immediate medical advice.

What should be avoided?

The use of hydrochlorothiazide can increase your risk of skin cancer. Avoid tanning beds or sunlight. When you're outdoors, wear protective clothing and use sunblock with an SPF of 30 or more. You may be asked to undergo regular skin checks by your doctor.Use potassium supplements and salt substitutes only if your doctor recommends them.Alcohol can lower blood pressure further and cause adverse effects.Avoid overheating or dehydration during exercise, in hot weather, or by drinking too little fluid.

Interaction with other drug

Take your hydrochlorothiazide/losartan dose four hours before or four to six hours after taking cholestyramine.

Tell your doctor about your other medications, including:

  • A diuretic, or "water pill".
  • Other blood pressure medications
  • Lithium
  • Aspirin, Ibuprofen, Naproxen, Diclofenac, and Indomethacin are all nsaids.

This list is incomplete. Hydrochlorothiazide, losartan, and other drugs can interact with each other. This includes prescription and over-the-counter medicines, vitamins, and herbal products. This list does not include all possible drug interactions