What is losartan used for?

What is losartan? | Uses | How it works | Dosages | How to take losartan | Safety information and side effects | Losartan alternatives | Recalls | Savings 

Losartan (losartan potassium) is a prescription blood pressure medicine. It is used to treat high blood pressure. Lowering blood pressure decreases the risks of strokes and heart attacks. Losartan can also be used to lower the risk of stroke in people with high blood pressure and left ventricular hypertrophy (LVH). LVH is a thickening of the wall of the heart’s main pumping chamber, which can cause the heart to not pump efficiently. Losartan can also be used to treat diabetic nephropathy (kidney disease resulting from diabetes) in patients with high blood pressure and Type 2 diabetes. 

What is losartan?

Losartan is a generic prescription drug used to treat hypertension (high blood pressure). It can also prevent stroke and treat diabetic nephropathy. Losartan is a prescription drug. It cannot be purchased over-the-counter. 

The brand name of losartan is called Cozaar. Losartan can also be found as an ingredient in the drug Hyzaar, which contains two ingredients: losartan and hydrochlorothiazide. This article will focus on the single-ingredient medication losartan. 

Losartan is part of a drug class called angiotensin II receptor blockers, or ARBs. ARBs work by preventing a substance called angiotensin II from binding to its receptor. Angiotensin II causes blood vessels to narrow and blood pressure to increase when it binds to its receptors. By blocking angiotensin II from binding to its receptors, losartan helps lower blood pressure. Losartan is made by several generic manufacturers. Brand-name Cozaar is made by the pharmaceutical company Organon. 

What is losartan used for?

Losartan is used for several conditions. Losartan can be used alone or with other medications. Many patients require more than one drug. The doctor will also usually recommend other measures as needed, such as diet and exercise, smoking cessation, and managing other conditions like diabetes and high cholesterol. 

Hypertension (high blood pressure)

Losartan can be used to treat hypertension in adults and children ages 6 years and older. By lowering blood pressure, the risk of heart attacks and strokes decreases. 

When looking at a blood pressure reading, systolic blood pressure is the top number, and diastolic is the bottom number. For reference, according to the American Heart Association, the five blood pressure ranges include:

• Normal: Systolic less than 120 and diastolic less than 80
• Elevated: Systolic 120-129 and diastolic less than 80
• Hypertension Stage 1: Systolic 130-139 OR diastolic 80-89
• Hypertension Stage 2: Systolic 140 or higher OR diastolic 90 or higher
• Hypertensive crisis (requires immediate medical attention): Systolic higher than 180 and/or diastolic higher than 120

Prevention of stroke in patients with left ventricular hypertrophy

Losartan can be used to lower the risk of stroke in people who have both hypertension and left ventricular hypertrophy (LVH). 

This benefit may not apply to African American patients. A clinical trial called the LIFE study found that Black people with hypertension and LVH who took a beta-blocker medicine called atenolol had a lower risk of stroke, heart attack, or cardiovascular death than those who took losartan. 

Treatment of diabetic nephropathy

Losartan can be used to treat diabetic nephropathy (with increased serum creatinine and proteinuria) in patients with Type 2 diabetes and a history of high blood pressure. Losartan can slow the rate of kidney disease progression. 

Treatment of heart failure

Losartan can be used off-label for the treatment of heart failure. Off-label prescribing is when a drug is prescribed for a purpose that is not approved by the US Food and Drug Administration (FDA). This use for losartan was recommended in studies called ELITE and ELITE II. For this purpose, losartan is generally used along with a beta-blocker and an aldosterone antagonist (such as eplerenone or spironolactone) in patients with reduced ejection fraction heart failure NYHA class I to IV. Losartan may reduce morbidity (illness) and mortality (death).  

How does losartan work?

Losartan is in a class of drugs called angiotensin receptor blockers, or ARBs. ARBs work on a system in the body called the renin-angiotensin system. The liver produces a protein called angiotensin. The body converts angiotensin into angiotensin II. Angiotensin II binds to receptors (imagine a key going into a lock) in order to exert its activity. Too much angiotensin II can narrow the blood vessels and raise blood pressure. It can also cause the body to retain fluid. ARB drugs, like losartan, block the receptor (lock) so that angiotensin II (the key) cannot bind to it. Without angiotensin II binding to the receptor, the blood vessels can relax and stay open, allowing blood to flow freely. 

Losartan works relatively quickly, with many patients seeing the maximal effects within the first week of treatment. However, some studies show that the maximal effect may take up to six weeks of treatment. 

Standard losartan dosages

Losartan is available in an oral tablet (a tablet that is taken by mouth). It is available in 25 mg, 50 mg, and 100 mg tablets. 

Hypertension

The usual starting dose for adults with high blood pressure is 50 mg daily. If this dose is not enough to control blood pressure, the healthcare provider may increase the dose to 100 mg daily (either 50 mg twice daily, or 100 mg once daily). 

For children and adolescents ages 6 to 17 years old, the dosage is based on weight, with a maximum dose of 50 mg daily to start, and a maximum of 100 mg per day as a maintenance dose. 

Prevention of stroke in adults with hypertension and LVH

The healthcare provider will generally start the patient with 50 mg once daily, and monitor for up to six weeks. If further blood pressure reduction is needed, a diuretic (often referred to as a “water pill”) called hydrochlorothiazide (HCTZ) may be added at 12.5 mg daily, and/or the losartan dose may be increased to 100 mg daily. If further blood pressure control is needed, the HCTZ dose may be increased to 25 mg daily. 

Diabetic nephropathy

An initial dose of 50 mg once daily will be used. The doctor may increase the dose to 100 mg daily if needed, based on blood pressure response. 

Heart failure

The dosage for heart failure, which is an off-label treatment, will start at 25 to 50 mg once daily. The dose may be increased as needed up to 50 to 150 mg per day. Losartan will be used along with a beta-blocker and an aldosterone receptor antagonist such as spironolactone or eplerenone.

Note: the maximum dose of losartan for other uses is 100 mg, and the maximum dose of 150 mg is only used in heart failure patients when needed. 

How to take losartan

Losartan is available as a tablet that is taken by mouth. It is generally taken as a daily dose of 50 to 100 mg. It starts working quickly. Many patients see an improvement in blood pressure within one week, although it can take up to three to six weeks to see the maximum effect of losartan. 

Before taking losartan, carefully read the prescription label to ensure you follow the correct directions for use. Read the patient information leaflet from your pharmacy and ask your pharmacist or healthcare provider if you have any questions. 

Losartan should be stored at room temperature, away from direct heat, light, and moisture. Do not store losartan or other medications in the bathroom. Keep losartan out of reach and out of sight of children and pets. 

Losartan can be taken with or without food. You can take losartan at any time of the day that is convenient for you. It is best to take losartan at about the same time every day to maintain consistent levels in the body. Using a medicine organizer, reminder app, or alarm can help you remember to take your medication every day. 

Follow your healthcare provider’s recommendations for checking blood pressure at home, as well as lab tests. Your provider may also recommend other measures such as a low-salt diet and increased exercise that can help lower your blood pressure.

Many people with high blood pressure do not have symptoms. When you take losartan, it is working even though you may not feel a difference in your body. It is important to continue to take your medication as directed because it can prevent short-term and long-term problems. If you have any concerns, discuss them with your healthcare provider. Do not stop taking losartan unless you are having a serious allergic reaction—or if your healthcare professional tells you to stop. If you do stop taking losartan for any reason, you should not have any withdrawal symptoms. 

Losartan may cause dizziness, especially when standing up. Avoid standing up too fast from a sitting down or lying down position. 

Take losartan once or twice daily as directed. In the event of a missed dose, take it as soon as you remember. However, if it is almost time for the next dose, skip the missed dose. Do not double up on doses to try to make up for a missed dose. 

If you think you took too much losartan, call Poison Control at 1-800-222-1222. A losartan overdose may cause low blood pressure and/or changes in heart rate. 

If you are sick with vomiting or diarrhea, or if you are sweating more than usual, contact your doctor. You can become dehydrated while taking losartan, which can cause very low blood pressure, electrolyte imbalance, or kidney damage or failure if untreated. 

Losartan safety information

Restrictions

Losartan can be used in adults and children 6 years and older. It should not be used in children under 6 years old. One exception is in the case of children 1 year and older who may be prescribed losartan for aortic dilation due to Marfan syndrome. 

Older adults can generally take the same doses (50 to 100 mg daily) of losartan. However, the doctor will monitor carefully as some individuals may have a greater sensitivity and will require a lower dose. 

People with mild or moderate liver problems will generally be prescribed a 25 mg daily dose of losartan to start. Those with severe liver problems should not take losartan. 

People with kidney problems can often take the regular dose of losartan, although those who are volume-depleted (low plasma due to sodium loss) will require a lower dose.

Losartan has a black box warning, which is the strongest warning required by the FDA. Losartan should not be taken by pregnant women, because it could cause harm or death to the unborn baby in the second or third trimester of pregnancy. If you already take losartan and find out you are pregnant, notify your doctor right away. Losartan should be stopped as soon as possible. 

Women who are breastfeeding should not take losartan because it could cause harm to the baby. 

Warnings

Before taking losartan, tell your doctor about your medical history and family history. Losartan warnings include:

• Pregnancy (see above section): ARBs as well as ACE inhibitors can cause harm and/or death to the unborn baby in the second and third trimesters of pregnancy. If pregnancy is detected, losartan should be stopped as soon as possible. 
• Low blood pressure in patients who are volume-depleted or salt-depleted: Any problems with volume or salt depletion should be corrected before starting losartan. Otherwise, losartan could cause severely low blood pressure.
• Kidney function deterioration: Losartan (as well as diuretics, which are often prescribed along with losartan) can cause acute kidney failure. Patients who have certain conditions such as kidney disease, heart failure, renal artery stenosis, or volume depletion, are at higher risk of developing kidney failure. In these patients, kidney function will be monitored. 
• Hyperkalemia (high potassium levels): Potassium levels should be monitored while taking losartan. Taking other medications that can increase potassium, along with losartan, can lead to hyperkalemia. 

Side effects

Like any drug, losartan can cause side effects. Before taking losartan, discuss possible side effects with your doctor. Common side effects may include: 

• Stomach issues like diarrhea or indigestion
• Tiredness and weakness
• Muscle and joint pain
• Chest pain
• Cough 
• Upper respiratory infection
• Low blood pressure
• High potassium levels
• Dizziness 

Serious side effects may include:

• Allergic reactions: Get emergency medical help right away if you experience hives, difficulty breathing, or swelling of the face, lips, tongue, or throat
• Severely low blood pressure
• High potassium levels
• Kidney problems/kidney failure
• Rhabdomyolysis (muscle tissue breakdown that can damage the kidneys)
• Liver problems
• Low platelet levels

Interactions

Before taking losartan, tell your doctor about any allergies or reactions to medications, and all the medicines you take, including prescription and OTC drugs, vitamins, and supplements. Examples of losartan drug interactions include:

• Drugs that increase potassium: Drugs that increase potassium, when combined with losartan, can cause high potassium levels. Potassium levels should be monitored. Examples of these drugs include Aldactone (spironolactone), Inspra (eplerenone), and Prograf (tacrolimus). 
• Lithium: Combining lithium and losartan can increase lithium levels in the body and cause lithium toxicity. Lithium levels should be monitored closely if these drugs are taken together. 
• Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs can cause kidney problems, including kidney failure, in older adults, patients who take diuretics or are volume-depleted, and patients who have a history of kidney problems. Examples of NSAIDs include Celebrex (celecoxib), Mobic (meloxicam), Motrin (ibuprofen), and naproxen. Individuals who take an NSAID along with losartan will need to have kidney function monitored. 
• Dual blockage of the renin-angiotensin system (RAS): Besides losartan, other drugs work on the RAS—but in different ways—such as ACE inhibitors (like lisinopril or ramipril) and Tekturna (aliskiren). Combining one of these drugs (or another ARB such as valsartan) with losartan can increase the risk of low blood pressure, fainting, high potassium levels, and kidney problems or kidney failure. In rare cases, a patient may need to take two of these drugs together, although in most cases, two drugs that work on the RAS will not be combined. Patients who do need to take a combination of these drugs will be closely monitored. 
• Aliskiren or any medications that contain aliskiren should never be taken with losartan in patients with kidney problems or diabetes. 
• Monoamine oxidase inhibitors (MAOIs): MAOIs such as isocarboxazid or phenelzine should not be combined with losartan, because the combination could cause severely low blood pressure.

Some drugs can interact with certain foods or substances. For losartan, this may include:

• Alcohol: Alcohol can lower blood pressure, as does losartan. Ask your healthcare provider how much alcohol, if any, is safe for you to consume. 
• Caffeine: Talk to your healthcare provider about caffeine consumption. Caffeine can increase blood pressure, and work against losartan. 
• Potassium supplements: Check with your doctor before using salt substitutes that contain potassium. 

This is not a full list of drug interactions and others may occur. Consult your healthcare provider for a full list of drug interactions. 

Losartan alternatives

There are many alternatives to losartan. Some patients may need an alternative, while others may need additional blood pressure control, so the best option would depend on the reason for seeking an alternative, among other individual patient factors.

For example, another ARB may be an option for a replacement, but would not be combined with losartan. Some other ARBs include:

• Benicar (olmesartan): This medication is available in brand and generic. It can be used alone or with other medications to treat high blood pressure in adults and children ages 6 years and older. 
• Diovan (valsartan): Diovan is also available in brand and generic. It can be used alone or with other medications to treat high blood pressure in adults and children ages 1 year and older. It can also be used to lower the risk of hospitalization in adults with heart failure or to lower the risk of death from a heart attack in adults with left ventricular failure or left ventricular dysfunction. 
• Edarbi (azilsartan): Edarbi is only available in the brand name—there is not a generic available at this time. Edarbi can be used alone or with other medications to treat high blood pressure in adults. It is not approved for use in children.

Another replacement could be an ACE inhibitor. Like ARBs, it would be a replacement, but not combined with losartan. Examples include:

• Altace (ramipril): This drug is available in brand and generic and can be used alone or with a thiazide diuretic (such as hydrochlorothiazide) to treat high blood pressure in adults. It can also be used in adults 55 years and older at high risk of a major cardiovascular event (such as heart attack, stroke, or cardiovascular death) due to other risk factors. It can also be used after a heart attack in patients with congestive heart failure. 
• Vasotec (enalapril): Vasotec is available in brand and generic and can be used alone or with other medicines to treat high blood pressure in adults and children one month and older. It can also be used with diuretics and digoxin to treat heart failure. Another use is reducing the risk of heart failure in patients with left ventricular dysfunction. 
• Zestril (lisinopril): Zestril is available in brand and generic. It can be used alone or with other medications to lower blood pressure in adults and children 6 years and older. It can also be used to treat heart failure. Another use is to reduce the risk of death after a heart attack, along with other medications. 

Note: Some people experience a dry cough as a side effect of ACE inhibitors. If you are taking an ACE inhibitor and experience a dry cough, consult your healthcare provider.

Some patients may tolerate losartan well, but the doctor may add a diuretic, such as hydrochlorothiazide, for additional blood pressure control. Or, instead of prescribing both losartan and hydrochlorothiazide separately, the doctor may instead prescribe Hyzaar, which contains both losartan and hydrochlorothiazide. 

In some cases, a beta-blocker or calcium channel blocker may be substituted or added. Examples are:

• Tenormin (atenolol): This beta-blocker medication is available in brand and generic and can be used alone or with other drugs to lower blood pressure in adults. It can also be used in patients with angina (chest pain), or to reduce the risk of death after a heart attack.
• Toprol XL (metoprolol succinate extended-release): This beta-blocker drug is available in brand and generic and can be used alone or with other drugs to lower blood pressure in adults and children 6 years and older. It can also be used to treat angina or to lower the risk of death and hospitalization in patients with heart failure.
• Norvasc (amlodipine): This calcium channel blocker drug is available in brand and generic. Norvasc can be used alone or with other medicines to lower blood pressure in adults and children 6 years and older. It can also be used to treat angina and coronary artery disease.

These are just a few of the most popular blood pressure medications prescribed. You can find a full list of blood pressure drugs on the American Heart Association website. 

Losartan recalls

In 2019, there were several losartan recalls, along with recalls on other ARBs. This was due to small amounts of an impurity found in the medication. Currently, there are no recalls of losartan. All losartan found in pharmacies is safe to take. 

Losartan savings

Because losartan is a generic drug, most insurance, and Medicare prescription plans should cover the medicine at a reasonable cost. However, those who pay out-of-pocket or need other assistance can access a free SingleCare card from the website or mobile app. Anyone in the United States with a valid prescription can use SingleCare at participating pharmacies. A typical prescription of losartan 50 mg, 30 tablets, would normally cost about $55 if you paid out-of-pocket. However, using a free SingleCare losartan card could lower the cost to as low as $3. What’s more, you can use SingleCare to save on refills, too. Our customers can save up to 80% off the cost of prescription prices. Ask your pharmacist to check your price with the SingleCare card.