Olmesartan 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 the 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.

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

In addition to taking this medicine, treatment for your high blood pressure may include weight control and a change in the foods you eat, especially foods high in sodium (salt). Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure, but it does help control it. You must continue to take it as directed if you expect to lower your blood pressure and keep it down. You might have to take high blood pressure medicine for the rest of your life. If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

This medicine may be taken with or without food.

If your child cannot swallow the tablets, your doctor may give him/her an oral liquid that is to be prepared by a pharmacist.

To use the oral liquid:

Shake the oral liquid well before each use.
Measure the medicine with a marked measuring spoon, oral syringe, or medicine cup. The average household teaspoon may not hold the right amount of liquid.
Store the oral liquid in the refrigerator for up to 4 weeks. Throw away any unused medicine after 4 weeks.
If you are also using colesevelam (Welchol®), take it at least 4 hours after taking Benicar®.

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

Blood in the urine

body aches or pain

chills

cough or cough producing mucus

difficulty with breathing

ear congestion

fever

headache

loss of voice

nasal congestion

runny nose

sneezing

sore throat

tightness in the chest

unusual tiredness or weakness

Rare

Bladder pain

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

chest pain

cloudy urine

difficult, burning, or painful urination

fast, pounding, or irregular heartbeat or pulse

frequent urge to urinate

joint pain, stiffness, or swelling

lower back, side, or stomach pain

swelling of the feet or lower legs

Incidence not known

Confusion

dark-colored urine

diarrhea (severe) with weight loss

dizziness

hives

itching

large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs

muscle cramps or spasms

muscle pain or stiffness

nausea or vomiting

weakness or heaviness of the legs

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

Blurred vision

chest pain or discomfort

dizziness, faintness, or lightheadedness

sweating

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:

Less common

Back pain

diarrhea

dry mouth

flushed, dry skin

fruit-like breath odor

general feeling of discomfort or illness

increased hunger

increased thirst

increased urination

loss of appetite

muscle aches

pain or tenderness around the eyes and cheekbones

shivering

tender, swollen glands in the neck

trouble sleeping

trouble swallowing

unexplained weight loss

Rare

Acid or sour stomach

belching

difficulty with moving

feeling of constant movement of self or surroundings

heartburn

indigestion

rapid weight gain

rash

sensation of spinning

tingling of the hands or feet

unusual weight gain or loss

Incidence not known

Hair loss or thinning of the hair

lack or loss of strength

redness of the skin

welts

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 the progress of you or your child at regular visits to make sure this medicine is working properly. Blood 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 or lightheadedness may occur after the first dose of this medicine, especially if you have been taking a diuretic (water pill). Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy.

Check with your doctor right away if you or your child become sick while taking this medicine, especially with severe or continuing nausea, vomiting, or diarrhea. These conditions may cause you to lose too much water, and may 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.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.