Why is this medication prescribed?
Losartan is used alone or in combination with other medications to treat high blood pressure. Losartan is also used to decrease the risk of stroke in people who have high blood pressure and a heart condition called left ventricular hypertrophy (enlargement of the walls of the left side of the heart). Losartan may not decrease the risk of stroke in African Americans who have these conditions. This medication is also used to treat kidney disease in people who have type 2 diabetes (condition in which the body does not use insulin normally and therefore cannot control the amount of sugar in the blood) and high blood pressure. Losartan is in a class of medications called angiotensin II receptor antagonists. It works by blocking the action of certain natural substances that tighten the blood vessels, allowing the blood to flow more smoothly and the heart to pump more efficiently.
High blood pressure is a common condition, and when not treated it can cause damage to the brain, heart, blood vessels, kidneys, and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.
How should this medicine be used?
Losartan comes as a tablet to take by mouth. It is usually taken once or twice a day with or without food. To help you remember to take losartan, take it at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take losartan exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of losartan and gradually increase your dose.
If your child can not swallow a tablet, talk to your doctor or pharmacist. The pharmacist can prepare a liquid form of this medication for your child.
Losartan controls high blood pressure but does not cure it. Your blood pressure may decrease during the first week of your treatment, but it may take 3 to 6 weeks for you to notice the full benefit of losartan. Continue to take losartan even if you feel well. Do not stop taking losartan without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.
Other uses for this medicine
Losartan is also sometimes used to treat heart failure (condition in which the heart is unable to pump enough blood to the rest of the body). Talk to your doctor about the possible risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking losartan,
- tell your doctor and pharmacist if you are allergic to losartan, any other medications, 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 medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin, in Lotrel), captopril (Capoten, in Capozide), enalapril (Vasotec), fosinopril, lisinopril (in Prinzide, in Zestoretic), moexipril (Univasc, in Uniretic), perindopril (Aceon), quinapril (Accupril, in Accuretic, in Quinaretic), ramipril (Altace), and trandolapril (Mavik, in Tarka); aspirin and other nonsteroidal anti-inflammatory medications (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), spironolactone (Aldactone, in Aldactazide), and triamterene (Dyrenium, in Dyazide, in Maxzide); fluconazole (Diflucan); lithium ( Lithobid); phenobarbital; potassium supplements; and rifampin (Rifadin, Rimactane, in Rifamate, in Rifater). Your doctor may need to change the doses of your medications 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 breastfeeding.
- 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.
What special dietary instructions should I follow?
Do not use salt substitutes containing potassium without talking to your doctor. If your doctor prescribes a low-salt or low-sodium diet, follow these directions carefully.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Losartan may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- leg, knee, or back pain
- muscle cramps or weakness
- decreased sensitivity to touch
Some side effects can be serious. If you experience any of these symptoms or those listed in the SPECIAL PRECAUTIONS section, call your doctor immediately:
- swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- difficulty breathing or swallowing
- chest pain
Losartan may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat, light, and moisture (not in the bathroom).
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.
In case of emergency/overdose
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.
Symptoms of overdose may include the following:
- fast or slow heartbeat
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to losartan.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Brand names of combination products
- Hyzaar® (containing Hydrochlorothiazide, Losartan)