Losartan-Hydrochlorothiazide Losartan Hydrochlorothiazide is a combination medication prescribed to address hypertension by lowering blood pressure. Losartan is an angiotensin receptor blocker (ARB) that relaxes blood vessels and Hydrochlorothiazide a diuretic that increases urination and removes excess water. It is taken orally as a tablet. Read more about hypertension.
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How to use this information
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective or appropriate for you. This information is not individual medical advice and does not substitute for the advice of a medical provider. If you have any questions, go to your patient dashboard and request a callback for complete information about this product and your specific health needs.
Medication name




Warnings to be aware of
  • This drug can cause serious and possibly fatal harm to an unborn baby if used during pregnancy. It is important to prevent pregnancy while taking this medication.
  • Consult your medical provider for more details and to discuss the use of reliable forms of birth control while taking this medication.
  • If you are planning pregnancy, become pregnant or think you may be pregnant, contact your medical provider right away.
What you should know about Losartan/Hydrochlorothiazide
  • This drug is used to treat high blood pressure. 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.
  • This product contains two medications—Losartan and Hydrochlorothiazide:

    • Losartan is an angiotensin receptor blocker (ARB) and works by relaxing blood vessels so that blood can flow more easily.
    • Hydrochlorothiazide is a "water pill" (diuretic) that causes you to make more urine, which helps your body get rid of extra salt and water.
How to take Losartan/Hydrochlorothiazide
  • Read the Patient Information Leaflet if available from your pharmacist before you start taking Losartan/Hydrochlorothiazide and each time you get a refill. If you have any questions, ask your medical provider or pharmacist.
  • Take this medication by mouth as directed by your medical provider, usually once daily with or without food. If this medication causes you to urinate more frequently, it is best to take it at least 4 hours before your bedtime to prevent having to get up to urinate.
  • If you also take certain drugs to lower your cholesterol—for example, bile acid-binding resins such as Cholestyramine or Colestipol—take Losartan/Hydrochlorothiazide at least 4 hours before or at least 4 to 6 hours after these medications.
  • The dosage is based on your medical condition and response to treatment.
  • Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick.
  • Tell your medical provider if your condition does not improve or if it worsens—for example, your blood pressure readings increase.
Potential side effects
  • Dizziness or lightheadedness may occur as your body adjusts to the medication. If any of these effects continue or get worse, tell your medical provider or pharmacist right away.
  • To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
  • Angioedema is a rare but potential side effect. Symptoms include swelling of the lips, tongue, throat or neck. This is not considered an allergic reaction and can occur any time during treatment. This swelling can compromise the airway and be life threatening. Black patients and patients with a personal or family history of angioedema are at higher risk. If you believe you may be at higher risk, discuss alternative treatment options with your medical provider.
  • Remember that this medication has been prescribed because your medical provider has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not experience serious side effects.
  • This product may cause dehydration and electrolyte imbalance. Tell your medical provider right away if you have any symptoms of dehydration or electrolyte imbalance, including:

    • Extreme thirst
    • Very dry mouth
    • Muscle cramps or weakness
    • Fast, slow or irregular heartbeat
    • Confusion
  • Tell your medical provider right away if any of these unlikely but serious side effects occur:

    • Fainting
    • Decrease in vision
    • Eye pain
    • Symptoms of a high potassium blood level, such as muscle weakness or slow/irregular heartbeat
    • Signs of kidney problems, such as change in amount of urine
  • A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

    • Rash
    • Itching or swelling, especially of the face/tongue/throat
    • Severe dizziness
    • Trouble breathing
  • This is not a complete list of possible side effects. If you notice other effects not listed above, request a callback for medical advice. You may also report side effects to the FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

Precautions to be aware of
  • Before taking this medication, tell your medical provider or pharmacist if you are allergic to Losartan or Hydrochlorothiazide, or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Go to your patient dashboard and request a medical provider callback for more details.
  • Before using this medication, tell your medical provider or pharmacist your medical history, especially of:

    • An allergy to sulfonamides ("sulfa") because there may be cross-reactivity between the two classes of drugs
    • Aortic stenosis
    • Dehydration
    • Glaucoma or other vision issues
    • Gout
    • High cholesterol because the diuretics can increase cholesterol and triglyceride levels
    • High levels of potassium in the blood
    • Hypertrophic cardiomyopathy or renal artery stenosis
    • Kidney disease
    • Liver disease
    • Lupus
    • Parathyroid disease or history of high calcium levels
    • Porphyria
    • Skin cancer
  • This drug may make you dizzy, which can be exacerbated by alcohol or marijuana (cannabis). Do not drive, use machinery or do anything that requires alertness until you can do it safely. Limit alcoholic beverages. Talk to your medical provider if you are using marijuana.
  • Severe sweating, diarrhea or vomiting can increase the risk for lightheadedness or dehydration. Report prolonged diarrhea or vomiting to your medical provider. To prevent dehydration, drink plenty of fluids unless your medical provider directs you otherwise.
  • If you have diabetes, this product may affect your blood sugar. Check your blood sugar regularly as directed and share the results with your medical provider. Your medical provider may need to adjust your diabetes medication, exercise program or diet.
  • This medication may make you more sensitive to the sun. It may also increase your risk for skin cancer, especially if you take it for a long time. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your medical provider right away if you get sunburned, have skin blisters/redness or notice new or changed moles/skin lesions.
  • This product may affect your potassium levels. Before using potassium supplements or salt substitutes that contain potassium, consult your medical provider or pharmacist.
  • Before having surgery, tell your doctor or dentist about all the products you use, including prescription drugs, nonprescription drugs and herbal products.
  • Older adults may be more sensitive to the side effects of this drug, especially dizziness and change in amount of urine (kidney problems).
  • Tell your medical provider if you are pregnant or plan to become pregnant. You should not become pregnant while using Losartan/Hydrochlorothiazide, as it may harm an unborn baby. If you become pregnant, talk to your OB/GYN right away about the risks and benefits of this medication (see also “Warnings to be aware of” section).
  • It is unknown if Losartan passes into breast milk. Hydrochlorothiazide passes into breast milk, but is unlikely to harm a nursing infant. Consult your OB/GYN before breastfeeding.
Drug interactions (see also “How to take Losartan/Hydrochlorothiazide” and “Precautions to be aware of” sections)
  • Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions.
  • Keep a list of all the products you use—including prescription/nonprescription drugs and herbal products—and share it with your medical provider and pharmacist.
  • Do not start, stop or change the dosage of any medicines without your medical provider's approval.
  • Some products that may interact with this drug include:

    • Aliskiren
    • Allopurinol
    • Dofetilide
    • Licorice
    • Lithium, Duloxetine and some other antipsychotic medications
    • Multivitamins and vitamin D supplements
    • Some diabetes medications
    • Some heart medication
    • Steroids
    • Drugs that may increase the level of potassium in the blood (such as ACE inhibitors including Benazepril or Lisinopril, antibiotics such as Bactrim and birth control pills containing Drospirenone).
  • Some products have ingredients that could raise your blood pressure or worsen your heart failure. Tell your pharmacist what products you are using, and ask how to use them safely—especially cough-and-cold products, diet aids or NSAIDs such as Ibuprofen and Naproxen.
  • This medication may interfere with certain laboratory tests—including parathyroid function—possibly causing false test results. Make sure laboratory personnel and all your medical providers know you use this drug.
What to do in the event of an overdose

Symptoms of overdose may include severe dizziness or fainting.

If someone has overdosed and has serious symptoms—such as passing out or trouble breathing—call 911. If symptoms from taking this medication are less severe, call your local poison control center at 1-800-222-1222 right away.

Additional notes
  • Do not share this medication with others.
  • Lifestyle changes such as stress reduction programs, exercise and dietary changes may increase the effectiveness of this medicine. Talk to your medical provider or pharmacist about lifestyle changes that might benefit you.
  • Lab and/or medical tests—such as kidney function, potassium levels and skin exams—should be done while you are taking this medication. Keep all medical and lab appointments. Consult your medical provider for more details.
  • Check your blood pressure regularly while taking this medication. Learn how to monitor your own blood pressure, and share the results with your medical provider.
What to do if you miss a dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

How to store this medication
  • Store at room temperature away from light and moisture. Do not store in the bathroom.
  • Keep all medications away from children and pets.
  • Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details.
Treatment for
Generic Name
Drug Class
ARB / Diuretic (water pill) combo

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