Health Library

Losartan/hydrochlorothiazide (By mouth)

Hydrochlorothiazide (hye-droe-klor-oh-THYE-a-zide), Losartan Potassium (loe-SAR-tan poe-TAS-ee-um)

Treats high blood pressure. This medicine contains an angiotensin receptor blocker (ARB) and a diuretic (water pill).

Brand Name(s):

Hyzaar

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• Swallow the tablet whole. Do not break, crush, or chew it.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Do not use this medicine together with aliskiren if you have diabetes.
• Some foods and medicines can affect how this medicine works. Tell your doctor if you are using any of the following:
  • Lithium, insulin or other diabetes medicine
  • Another blood pressure medicine
  • Diuretic (water pill)
  • NSAID pain or arthritis medicine (including aspirin, celecoxib, diclofenac, ibuprofen, naproxen)
• Ask your doctor before you use any medicine, supplement, or salt substitute that contains potassium.
• If you also use cholestyramine or colestipol, take it at least 4 hours after you take this medicine.
• Alcohol, narcotic pain relievers, or sleeping pills may cause you to feel more lightheaded, dizzy, or faint when used with this medicine.

Warnings While Using This Medicine:

• It is not safe to take this medicine during pregnancy, especially in your second or third trimester. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
• Tell your doctor if you are breastfeeding, or if you have kidney disease, liver disease (including cirrhosis), heart failure, diabetes, gout, high cholesterol, lupus, trouble urinating, or a history of asthma or allergies.
• This medicine may cause the following problems:
  • Kidney problems
  • Low or high levels of minerals in your blood, including potassium and sodium
  • Eye or vision problems, including glaucoma
  • Increased risk for skin cancer
• This medicine could lower your blood pressure too much, especially when you first use it or if you are dehydrated. Stand or sit up slowly if you feel dizzy or lightheaded. Do not drive or do anything dangerous until you know how this medicine affects you.
• Do not stop using this medicine without asking your doctor, even if you feel well. This medicine will not cure your high blood pressure, but it will help keep it in normal range. You may have to take blood pressure medicine for the rest of your life.
• This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Change in how much or how often you urinate, bloody urine, lower back or side pain, rapid weight gain, swelling in your hands, ankles, or feet
• Confusion, weakness, trouble breathing, numbness in your hands, feet, or lips
• Dry mouth, increased thirst, muscle twitching or cramps, nausea, vomiting
• Eye pain, vision changes, seeing halos around lights
• Fast, pounding, or uneven heartbeat
• Lightheadedness, dizziness, fainting
• Sores, reddish patch or irritated area, shiny bump, pink growth, or white, yellow or waxy scar-like area on the skin

If you notice these less serious side effects, talk with your doctor:

• Dry cough

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 9/6/2024