Olmesartan/hydrochlorothiazide (By mouth)

Hydrochlorothiazide (hye-droe-klor-oh-THYE-a-zide), Olmesartan Medoxomil (ol-me-SAR-tan me-DOX-oh-mil)

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

Brand Name(s):

Benicar HCT

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.
• 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.
• Ask your doctor before you use any medicine, supplement, or salt substitute that contains potassium.
• Some medicines can affect how this medicine works. Tell your doctor if you are using any of the following:
  • Cholestyramine, colestipol, lithium
  • ACE inhibitor blood pressure medicine
  • Diuretic (water pill)
  • Insulin or diabetes medicine
  • NSAID pain or arthritis medicine (including aspirin, celecoxib, diclofenac, ibuprofen, naproxen)
  • Steroid medicine (including dexamethasone, hydrocortisone, methylprednisolone, prednisolone, prednisone)
• If you also use colesevelam, take it at least 4 hours after you take this medicine.
• If you are taking cholestyramine or colestipol, take this medicine at least 4 hours before or 4 to 6 hours after these medicines.
• 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:

• This medicine is not safe to take during pregnancy, especially in your second or third trimester. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
• Do not breastfeed during treatment with this medicine.
• Tell your doctor if you have kidney problems or trouble urinating, liver disease, heart failure, diabetes, glaucoma, gout, high cholesterol, lupus, or a history of asthma or allergies, including a sulfa or penicillin allergy.
• This medicine may cause the following problems:
  • Kidney problems
  • Eye or vision problems, including angle-closure glaucoma, myopia
  • Severe chronic diarrhea with weight loss (could occur months to years after you start taking this medicine)
  • Increased risk for skin cancer
• This medicine could lower your blood pressure too much and cause you to feel dizzy or lightheaded. This is more likely to happen when you first use the medicine or if you become dehydrated. Stand or sit up slowly if you are dizzy.
• Drink plenty of fluids if you exercise, sweat more than usual, or have diarrhea or vomiting while you are using this medicine.
• 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
• Blistering, peeling, or red skin rash
• Change in how much or how often you urinate, bloody or cloudy urine
• Confusion, weakness, muscle twitching
• Dry mouth, increased thirst, muscle cramps, nausea, vomiting
• Eye pain, vision changes, seeing halos around lights
• Fast, slow, or uneven heartbeat, chest pain
• Lightheadedness, dizziness, or fainting
• Severe diarrhea with weight loss (could occur months to years after you start taking this medicine)
• 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:

• Cough, runny or stuffy nose, sore throat

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: 6/4/2025