What is losartan?


Generic Name: Losartan Brand Name(s): Generics only. No brands available.

Know the basics

What is losartan used for?

Losartan is used to treat high blood pressure (hypertension) and to help protect the kidneys from damage due to diabetes. It is also used to lower the risk of strokes in patients with high blood pressure and an enlarged heart. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Losartan belongs to a class of drugs called angiotensin receptor blockers (ARBs). It works by relaxing blood vessels so that blood can flow more easily.

OTHER USES: This section contains uses of losartan that are not listed in the approved professional labeling for the drug but that may be prescribed by your healthcare professional. Use losartan for a condition that is listed in this section only if it has been so prescribed by your health care professional.

Losartan may also be used to treat heart failure.

How should I take losartan?

Take losartan by mouth as directed by your doctor, usually once daily with or without food. The dosage is based on your medical condition and response to treatment.

If you are using the liquid form of losartan, shake the bottle well before each dose. Carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.

Use losartan regularly to get the most benefit from it. To help you remember, take it at the same time each day. It is important to continue taking losartan even if you feel well. Most people with high blood pressure do not feel sick.

Tell your doctor if your condition does not improve or if it worsens (for example, your blood pressure readings increase).

How do I store losartan?

Losartan is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store losartan in the bathroom or the freezer. There may be different brands of losartan that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush losartan down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Know the precautions & warnings

What should I know before using losartan?

Before taking losartan,

  • Tell your doctor and pharmacist if you are allergic to losartan, any other losartan, or any of the ingredients in losartan tablets. Ask your pharmacist for a list of the ingredients.
  • Tell your doctor if you have diabetes (high blood sugar) and you are taking aliskiren (tekturna, in amturnide, tekamlo, tekturna hct). Your doctor will probably tell you not to take losartan if you have diabetes and you are also taking aliskiren.
  • Tell your doctor and pharmacist what other prescription and nonprescription losartan, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: aspirin and other nonsteroidal anti-inflammatory losartan (nsaids) such as ibuprofen (advil, motrin) and naproxen (aleve, naprosyn), and selective cox-2 inhibitors such as celecoxib (celebrex); diuretics (‘water pills’) including potassium-sparing diuretics such as amiloride (midamor, in hydroride, in moduretic), spironolactone (aldactone, in aldactazide), and triamterene (dyrenium, in dyazide, in maxzide); fluconazole (diflucan); lithium (eskalith cr, eskalith, lithobid); phenobarbital; potassium supplements; and rifampin (rifadin, rimactane). Your doctor may need to change the doses of your losartan or monitor you carefully for side effects.
  • Tell your doctor if you have or have ever had heart failure or kidney or liver disease.
  • Tell your doctor if you are breast-feeding.
  • You should know that losartan may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. This is more common when you first start taking losartan. To help avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up.
  • You should know that diarrhea, vomiting, not drinking enough fluids, and sweating a lot can cause a drop in blood pressure, which may cause lightheadedness and fainting. Tell your doctor if you have any of these problems or develop them during your treatment.

Is it safe to take losartan during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using losartan during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking losartan. Losartan is pregnancy risk category  D according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Know the side effects

What are the side effects of losartan?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult 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 unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, and dark colored urine.

Call your doctor at once if you have: a feeling that you might pass out; pain or burning when you urinate; pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating; wheezing, chest pain; drowsiness, confusion, mood changes, increased thirst, loss of appetite, nausea and vomiting; swelling, weight gain, feeling short of breath, urinating less than usual or not at all; or high potassium (slow heart rate, weak pulse, muscle weakness, tingly feeling).

Common side effects may include: cold or flu symptoms such as stuffy nose, sneezing, sore throat, fever; dry cough; muscle cramps; pain in your legs or back; stomach pain, diarrhea; headache, dizziness; tired feeling; or sleep problems (insomnia).

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Know the interactions

What drugs may interact with losartan?

Losartan may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

  • A diuretic or “water pill”;
  • Other blood pressure losartan;
  • Lithium;
  • Celecoxib;
  • Aspirin or other nsaids (non-steroidal anti-inflammatory drugs) such as ibuprofen (advil, motrin), naproxen (aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

Does food or alcohol interact with losartan?

Losartan may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using losartan.

What health conditions may interact with losartan?

Losartan may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have, especially:

  • Angioedema (an allergic reaction) with other blood pressure medicines (eg, benazepril, enalapril, lisinopril, Lotrel®, Vasotec®, Zestoretic®, Zestril®), history of—Use may cause this condition to reoccur.
  • Congestive heart failure, severe—Use may lead to kidney problems.
  • Diabetic patients who are also taking aliskiren (Tekturna®).
  • Patients with kidney disease who are also taking aliskiren (Tekturna®)—Should not be used in patients with these conditions.
  • Electrolyte imbalances (eg, high or low potassium or sodium in the body)—Use with caution. May make these conditions worse.
  • Kidney disease;
  • Liver disease (including cirrhosis)—Use with caution. The effects may be increased because of slower removal of losartan from the body.

Understand the dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using losartan.

What is the dose of losartan for an adult?

Usual Adult Dose for Diabetic Nephropathy

  • Initial dose: 50 mg orally once a day.
  • Maintenance dose: 25 to 100 mg orally in 1 to 2 divided doses.

Usual Adult Dose for Hypertension

  • Initial dose: 50 mg orally once a day.
  • Maintenance dose: 25 to 100 mg orally in 1 to 2 divided doses.

What is the dose of losartan for a child?

Usual Pediatric Dose for Hypertension

  • Greater than or equal to 6 years: 0.7 mg/kg orally once daily (up to a maximum of 50 mg)

How is losartan available?

Losartan is available in the following dosage forms and strengths:

  • Tablet, Oral: 25 mg, 50 mg, 100 mg.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services (115) or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of losartan, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: May 30, 2016 | Last Modified: January 4, 2017

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