What is losartan?

Losartan is in a group of drugs called angiotensin II receptor antagonists. Losartan keeps blood vessels from narrowing, which lowers blood pressure and improves blood flow.

Losartan is used to treat high blood pressure (hypertension). It is sometimes given together with other blood pressure medications.

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

Precautions

You should not use this medication if you are allergic to losartan.

Before using losartan, tell your doctor if you are allergic to any drugs, or if you have:

  • kidney disease;
  • liver disease;
  • congestive heart failure; or
  • if you are dehydrated.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medication.

FDA pregnancy category D. This medication can cause harm to an unborn baby. Losartan may cause injury and even death to the unborn baby if you take it during the second and third trimesters of pregnancy. Do not use losartan without your doctor’s consent if you are pregnant. Use an effective form of birth control. Stop using this medication and tell your doctor right away if you become pregnant during treatment.

It is not known whether losartan passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Avoid drinking alcohol. It can lower your blood pressure and may increase some of the side effects of losartan.

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

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

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Instructions

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include fast or slow heartbeat, dizziness, or feeling like you might pass out.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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Side Effects

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, 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.

Call your doctor at once if you have any other serious side effects, such as:

  • feeling like you might pass out;
  • painful or difficult urination;
  • chest pain;
  • numbness or tingly feeling;
  • pale skin, easy bruising or bleeding;
  • swelling in your hands or feet; or
  • slow heart rate, weak pulse, tingly feeling.

Less serious side effects may include:

  • runny or stuffy nose, sore throat, cough;
  • muscle, leg, or back pain;
  • stomach pain, diarrhea;
  • headache, dizziness;
  • tired feeling; or
  • sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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Interactions

Before taking losartan, tell your doctor if you are using any of the following drugs:

  • a diuretic (water pill);
  • lithium (Eskalith, LithoBid, Lithonate); or
  • celecoxib (Cerebrex).

This list is not complete and there may be other drugs that can interact with losartan. 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.

Other Names

Cozaar and losartan

Available Strengths & Dosages


Route Form Strength
oral tablet 25 mg
oral tablet 50 mg
oral tablet 100 mg

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Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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