Olmesartan and hydrochlorothiazide combination is used alone or together with other medicines to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. Lowering blood pressure can reduce the risk of strokes and heart attacks.

Olmesartan is an angiotensin II receptor blocker (ARB). It works by blocking a substance in the body that causes blood vessels to tighten. As a result, olmesartan relaxes the blood vessels. This lowers blood pressure and increases the supply of blood and oxygen to the heart.

Hydrochlorothiazide is a thiazide diuretic (water pill). It reduces the amount of water in the body by increasing the flow of urine, which helps lower the blood pressure.

This medicine is available only with your doctor's prescription.

Take this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered.

Take this medicine with or without food.

If you are also using colesevelam (Welchol®), take it at least 4 hours after taking Benicar HCT®.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Bladder pain

bloating or swelling of the face, arms, hands, lower legs, or feet

bloody or cloudy urine

blurred vision

chest pain

difficult, burning, or painful urination

flushed, dry skin

frequent urge to urinate

fruit-like breath odor

increased hunger

increased urination

joint pain, stiffness, or swelling

lower back, side, or stomach pain

rapid weight gain

sweating

swelling of the feet or lower legs

tingling of the hands or feet

troubled breathing

unexplained weight loss

unusual weight gain or loss

Rare

Swelling or puffiness of the face

Incidence not known

Convulsions

decrease in amount of urine

dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position

rash

severe diarrhea with weight loss

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Back pain

body aches or pain

chills

cough

difficulty with breathing

ear congestion or pain

fever

headache

head congestion

hoarseness or other voice changes

loss of voice

runny or stuffy nose

sneezing

sore throat

Less common

Acid or sour stomach

belching

difficulty with moving

dizziness or lightheadedness

feeling of constant movement of self or surroundings

heartburn

indigestion

joint pain, stiffness, or swelling

loss of appetite

muscle pain or stiffness

pain, swelling, or redness in the joints

sensation of spinning

stomach discomfort or upset

weakness

Incidence not known

Diarrhea

muscle pain or stiffness

nervousness

weakness or heaviness of the legs

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Dizziness, lightheadedness, or fainting may also occur, especially when you get up suddenly from a lying or sitting position. Make sure you know how you react to the medicine before you drive, use machines, or do other things that could be dangerous if you are dizzy. If you feel dizzy, sit for a few moments before standing.

Check with your doctor right away if you become sick while taking this medicine, especially with severe or continuing nausea, vomiting, or diarrhea that does not stop. These conditions may cause you to lose too much water or salt and lead to low blood pressure. You can also lose water by sweating, so drink plenty of water during exercise or in hot weather.

Severe, chronic diarrhea with weight loss may develop months to years after taking this medicine. Tell your doctor right away if you have these symptoms.

Check with your doctor right away if blurred vision, difficulty with reading, eye pain, or any other vision change occurs with this medicine. This could be a sign of a serious eye problem. Your doctor may want an eye doctor to check your eyes.

This medicine may affect blood sugar levels. Diabetic patients may notice a change in the results of blood or urine sugar tests. Talk to your doctor if you have any questions.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.