- Losartan/hydrochlorothiazide oral tablet is available as a generic drug and a brand-name drug. Brand name: Hyzaar.
- Losartan/hydrochlorothiazide only comes as a tablet you take by mouth.
- Losartan/hydrochlorothiazide is a combination of two drugs in a single form. It’s used to treat high blood pressure and to reduce the risk of stroke in people with high blood pressure and damage to the heart (left ventricular hypertrophy).
FDA warning: Use during pregnancy
- This drug has a black box warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients about drug effects that may be dangerous.
- You should not take this drug while pregnant. This drug can harm or end your pregnancy. If you become pregnant, call your doctor and stop taking this drug right away.
- Low blood pressure (hypotension): Using this drug may cause low blood pressure. You’re more likely to have low blood pressure with this drug if you also take diuretics, are on a low-salt diet, have heart problems, or get sick with vomiting or diarrhea. If you have any of these medical problems, your doctor may monitor you closely when you receive your first dose.
- Sensitivity reaction: If you have a history of allergies or asthma, you may get a sensitivity reaction when you first start taking this drug. Symptoms include skin rash, hives, shortness of breath or wheezing, itching, and fever.
- Eye problems: This drug may cause eye conditions called myopias and glaucoma. If you have trouble seeing or pain in your eyes, call your doctor and stop taking the drug right away.
This drug is a prescription medication. It comes as an oral tablet.
This drug is available as the brand-name drug Hyzaar and as a generic drug. Generic drugs usually cost less. In some cases, they may not be available in every strength or form as the brand-name version.
This is a combination of two drugs in a single form. It’s important to know about all the drugs in the combination because each drug may affect you in a different way.
This drug may be used as part of a combination therapy. That means you need to take it with other drugs.
Why it's used
This drug is used treat high blood pressure. It’s given when one drug isn’t enough to lower your blood pressure.
This drug is also used to reduce the risk of stroke in people with high blood pressure and damage to the heart (left ventricular hypertrophy). The effectiveness of this drug may be related to your race. Ask your healthcare provider for more information about this topic.
This drug will help control your blood pressure, but it won’t cure it.
How it works
This drug belongs to a class of drugs called angiotensin II receptor blockers and thiazide diuretics. A class of drugs A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.
It’s thought that hydrochlorothiazide works to remove excess salt and water from your body. This keeps your heart from working as hard to pump blood. This lowers your blood pressure levels.
Losartan blocks the action of angiotensin II, a chemical in your body that causes your blood vessels to tighten and narrow. This drug helps to relax and widen your blood vessels, which lowers your blood pressure.
Losartan/hydrochlorothiazide oral tablet does not cause drowsiness, but it can cause other side effects.
More common side effects
The more common side effects that occur with losartan/hydrochlorothiazide include:
- upper respiratory infection, such as the common cold
- back pain
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.
Serious side effects
Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:
- serious allergic reaction, symptoms include:
- swelling of your face, lips, throat, or tongue
- low blood pressure (hypotension), symptoms include:
- feeling like you’re going to faint
- lupus, symptoms include:
- joint pain
- weight loss
- skin rash
- kidney problems, symptoms include:
- swelling of your feet, ankles, or hands
- weight gain
- eye problems, symptoms include:
- trouble seeing
- eye pain
- high or low potassium blood levels, symptoms can include:
- heart rhythm problems
- muscle weakness
- slow heart rate
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
Losartan/hydrochlorothiazide oral tablet can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.
To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.
Examples of drugs that can cause interactions with losartan/hydrochlorothiazide are listed below.
Potassium-sparing diuretics and supplements, and salt substitutes
Taking these drugs and supplements with losartan/hydrochlorothiazide may increase the amount of potassium in your blood to unsafe levels. You shouldn’t take losartan/hydrochlorothiazide with these drugs. Examples of these drugs include:
- potassium-sparing diuretics
- potassium supplements
- salt substitutes
Bipolar disorder drug
Taking lithium with losartan/hydrochlorothiazide can increase the levels of lithium in your blood. This can increase your risk of dangerous effects. Your doctor may reduce your dose of your bipolar disorder drug.
Nonsteroidal anti-inflammatory drugs (NSAIDs)
NSAIDs may reduce the effectiveness of losartan/hydrochlorothiazide. This means that it won’t work as well. Taking these drugs together may also damage your kidneys. You shouldn’t take NSAIDs with losartan/hydrochlorothiazide. Examples of NSAIDs include:
Blood pressure drugs
Taking other drugs that work in the same way as losartan/hydrochlorothiazide may increase your chance of low blood pressure, high potassium levels in your blood, and kidney damage.
Examples of these drugs include:
- angiotensin receptor blockers (ARBs), such as:
- angiotensin-converting enzyme (ACE) inhibitors, such as:
Your doctor may adjust the dose of your diabetes medications while you’re taking losartan/hydrochlorothiazide. Examples of these drugs include:
These drugs can decrease the amount of losartan/hydrochlorothiazide in your body. This means that it may not work as well. Your doctor may adjust the dose of losartan/hydrochlorothiazide if you’re taking this combination. Examples of these drugs include:
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
This drug comes with several warnings.
This drug can cause a severe allergic reaction. Symptoms include:
- trouble breathing
- swelling of your throat or tongue
If you develop these symptoms, call 911 or go to the nearest emergency room.
Don’t take this drug again if you’ve ever had an allergic reaction to it before. Taking it a second time after an allergic reaction could be fatal.
Alcohol interaction warning
The use of drinks that contain alcohol can increase your risk of dizziness or lightheadedness from losartan/hydrochlorothiazide. If you drink alcohol, talk to your doctor.
Warnings for people with certain health conditions
For people with a sulfonamide allergy: If you’re allergic to sulfonamides, don’t take this drug. Tell your doctor about all of your allergies.
For people with kidney disease: If you have kidney disease, you have a higher risk of serious side effects. If you have kidney disease and no longer make any urine, you shouldn’t take this drug. Your doctor will monitor your kidney function and adjust your medication as needed.
For people with liver disease: You shouldn’t take this drug if you have liver disease. It can cause changes in your fluid and electrolytes. This may lead to a coma if you have liver disease.
For people with lupus: This drug can cause new or worsening symptoms of lupus. Call your doctor right way if this occurs.
For people with diabetes: Your doctor may adjust the doses of your diabetes drugs while you’re taking this medicine. They’ll tell you how often to test your blood sugar levels.
For people with glaucoma: This drug may make your glaucoma worse.
Warnings for other groups
For pregnant women: This drug is a pregnancy category D drug. That means two things:
- Research in humans has shown adverse effects to the fetus when the mother takes the drug.
- This drug should only be used during pregnancy in serious cases where it's needed to treat a dangerous condition in the mother.
Talk to your doctor if you’re pregnant or planning to become pregnant. Ask your doctor to tell you about the specific harm that may be done to the fetus. This drug should only be used if the potential risk to the fetus is acceptable given the drug’s potential benefit.
Call your doctor right away if you become pregnant while taking this drug.
For women who are breastfeeding: It isn’t known if this drug passes into breast milk. If it does, it may cause side effects in a child who is breastfed.
Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.
For seniors: Older adults may process drugs more slowly. A typical adult dose may cause levels of this drug to be higher than normal in your body. If you’re a senior, you may need a lower dose or a different schedule. You may also be more likely to have side effects of this drug.
For children: This drug hasn’t been studied in children and shouldn’t be used in people younger than 18 years.
All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:
- your age
- the condition being treated
- how severe your condition is
- other medical conditions you have
- how you react to the first dose
Drug forms and strengths
- Form: oral tablet
- 50 mg losartan/12.5 mg hydrochlorothiazide
- 100 mg losartan/12.5 mg hydrochlorothiazide
- 100 mg losartan/25 mg hydrochlorothiazide
- Form: oral tablet
- 50 mg losartan/12.5 mg hydrochlorothiazide
- 100 mg losartan/12.5 mg hydrochlorothiazide
- 100 mg losartan/25 mg hydrochlorothiazide
Dosage for high blood pressure (hypertension)
Adult dosage (ages 18 to 64 years)
The starting dose is 50 mg losartan/12.5 mg hydrochlorothiazide or 100 mg losartan/12.5 mg hydrochlorothiazide, taken once per day. Your dose depends on the dose of the blood pressure drug that you were taking before. Your doctor may increase your dose up to 100 mg losartan/25 mg hydrochlorothiazide taken once per day if needed.
The maximum dosage is 100 mg losartan/25 mg hydrochlorothiazide taken once per day.
Child dosage (ages 0 to 17 years)
This drug hasn’t been studied in children and shouldn’t be used in people younger than 18 years.
Senior dosage (ages 65 years and older)
There are no specific recommendations for senior dosing. Older adults may process drugs more slowly. A normal adult dose may cause levels of this drug to be higher than normal. If you’re a senior, you may need a lower dose or a different schedule.
Special dosage considerations
- For people with kidney disease: You shouldn’t take this drug if your creatinine clearance (CrCl) is less than 30 ml/min.
- For people with liver disease: You shouldn’t take this drug if you have liver damage. A lower starting dose of losartan is needed for people with liver disease, but the lower dose is not available in this combination drug.
Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always speak with your doctor or pharmacist about dosages that are right for you.
Losartan/hydrochlorothiazide is used for long-term treatment. It comes with serious risks if you don’t take it as prescribed.
If you don't take it at all: This drug reduces high blood pressure. If this condition isn’t treated, it can lead to stroke, heart attack, heart failure, kidney failure, and vision problems. It can even be fatal.
If you stop taking it suddenly: Don’t stop taking this drug without talking to your doctor. High blood pressure can occur if you stop taking this drug too suddenly. This may increase your chance for a heart attack or stroke. If you need to stop taking this drug, your doctor will slowly decrease your dose.
If you don't take it on schedule: Your blood pressure may not improve or may get worse. You may have a higher chance of a heart attack or stroke.
What to do if you miss a dose: If you forget to take your dose, take it as soon as you remember. If it’s just a few hours until the time for your next dose, then wait and only take one dose at that time. Never try to catch up by taking two doses at once. This could cause dangerous side effects.
If you take too much: You may have more intense side effects, such as dizziness and changes in the amount of electrolytes in your blood. This may be dangerous.
How to tell this drug is working: Your blood pressure should be lower. Your doctor will monitor your blood pressure at your checkups. You can also check your blood pressure at home. Keep a log with the date, time of day, and your blood pressure readings. Bring this diary with you to your doctor appointments.
Keep these considerations in mind if your doctor prescribes losartan/hydrochlorothiazide for you.
You can cut or crush the tablet.
- Store this drug at room temperature close to 77°F (25°C). It may be stored briefly at a temperature between 59°F (15°C) and 86°F (30°C).
- Don’t freeze this drug. Keep it away from high temperatures.
- Keep this drug away from light.
- Don’t store this medication in moist or damp areas, such as bathrooms.
A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.
When traveling with your medication:
- Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
- Don’t worry about airport X-ray machines. They won’t damage your medication.
- You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
- Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.
You may need to check your blood pressure at home. You should keep a log with the date, time of day, and your blood pressure readings. Bring this diary with you to your doctor appointments.
While you’re being treated with this drug, your doctor will check your blood pressure and do blood tests to monitor the following:
- liver function
- kidney function
- blood sugar
- blood potassium
Your doctor may have you follow a special diet, such as a low-salt or a low-potassium diet. You may need to avoid potassium supplements and salt substitutes that contain potassium.
You may need to purchase a blood pressure monitor to check your blood pressure at home. These are available at most pharmacies.
There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.