GENERIC NAME: Olmesartan


Olmesartan is an oral antihypertensive prescription drug, belongs to a class of medications known as angiotensin receptor blockers (ARBs). It works by blocking the action of angiotensin II (a natural substance) and thereby relaxing blood vessels to flow blood smoothly and helps the heart to pump more efficiently.

It is available as the brand-name drug and generic drug. It is sold under the common brand “Benicar”. Generic drugs usually cost less.

What is Olmesartan used for?


Olmesartan is either used alone or in combination with other drugs to relieve high blood pressure. It also reduces the risk of stroke and heart attacks.

It is also used in the treatment of renal impairment.

How to use Olmesartan?

The dose of the drug is based on your medical condition and response to treatment. Take this drug orally as directed by your doctor, usually once a day with or without food.

Take the whole tablet with water or other liquids. Do not crush, break, or chew it. If you are using liquid form, shake the bottle well before each dose and use special measuring device/spoon.

If you are also taking cholesterol-lowering drugs such as cholestyramine, colestipol, colesevelam, take olmesartan at least 4-5 hours before any of these medications.

Take this drug regularly even if you feel well, this can help you get the maximum benefit from it. Preferably, take this drug at the same time each day to avoid confusion and missing of dose.

Take the tablet with a glass of water or other liquids. Do not crush, break, or chew it.

What are the side effects of Olmesartan?

The commonly observed side effect with this drug is dizziness or lightheadedness. If any of these effects remain or get worse, talk to your doctor or pharmacist immediately.

To lessen the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Get emergency medical assistance promptly, if symptoms of hyperkalemia (high potassium blood level) occur such as a slow/irregular heartbeat, muscle weakness, severe/persistent diarrhoea and feeling ill.

This drug very rarely causes serious kidney problems or make them worse, although it is used to improve kidney function. Inform your doctor on time, if you notice any signs of kidney problems like a change in the amount of urine, tiredness and shortness of breath.

Get emergency medical assistance right away if you notice any sign or symptoms of low blood pressure such as feeling faint or dizzy, lightheadedness and tiredness.

Allergic reaction to this medicine is very rare. However, get medical help promptly if you notice any symptoms of a severe allergic reaction, such as rash, itching/swelling (face/tongue/throat), breathlessness.

This is not a full record of all possible side effects. If you mark other effects not listed above, contact your doctor or pharmacist.

What are the precautions while using Olmesartan?

Before using olmesartan, notify your doctor or pharmacist if you are allergic to it or if you have any other allergies.

Inform your doctor or pharmacist about medical history, mainly of liver disease, kidney problems, dehydration (severe loss of body water and minerals), hyperkalemia (high blood levels of potassium in the blood).

Olmesartan may increase your blood potassium levels. Ask your doctor before you using any medicines, supplements, or salt substitutes that contain potassium.

Do not take alcoholic beverages until you have discussed with your doctor as alcohol may make the low blood pressure effect worse or increase the possibility of dizziness or fainting.

Do not take other medicines without consulting your doctor, primarily such as prescription or nonprescription (over-the-counter) medicines for asthma, colds, cough, hay fever, or sinus problems, and herbal or vitamin supplements.

The use of is this medicine is not recommended during pregnancy as it may harm to the fetus. Consult your doctor for further details.

It is not clear whether this drug can passes into breast milk. Consult your doctor before breastfeeding.

What are the drug interactions of Olmesartan?

Olmesartan may interact with other medications, vitamins, or herbs you may be using. A drug interaction is when a substance changes the way a drug works which can be harmful or hinder the drug from working well.

Do not start, stop, or alter the dose of the drug without consulting your doctor as your doctor may be monitoring you for possible drug interactions.

Taking angiotensin receptor blockers (losartan, valsartan, candesartan) and angiotensin-converting enzyme inhibitors (enalapril, lisinopril, captopril) with this drug may raise your risk of very low blood pressure, high blood potassium levels, and worsened kidney function.

Some products may interact with olmesartan such as lithium, aliskiren and birth control pills containing drospirenone.

Some medications contain inactive ingredients that could raise your blood pressure or worsen your heart failure. Tell your doctor what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs like ibuprofen/naproxen).

This drug may cause low blood pressure, and the risk of low blood pressure is higher if you also take diuretics (water pills). Examples of diuretics include hydrochlorothiazide, furosemide, spironolactone.


High blood potassium warning:

This drug may increase your blood levels of potassium. Your doctor will check your blood potassium levels during treatment with this drug.

Risk of hypotension warning:

This drug may cause hypotension (low blood pressure). Your doctor will observe you for low blood pressure at the time of dosage changes. Inform your doctor if you have any symptoms of low blood pressure, such as dizziness or lightheadedness.


This drug must not be taken in pregnancy or if you are planning to get pregnant. Olmesartan can harm the fetus or end your pregnancy. Inform your doctor right away if you are pregnant while using this drug.

What are the forms and strengths of Olmesartan?

Generic: Olmesartan
Form: Oral tablet
Strengths: 5mg, 20mg, 40mg

Brand: Benicar
Form: Oral tablet
Strengths: 5mg, 20mg, 40mg

What is the dosage of Olmesartan?

For High Blood Pressure (hypertension):

Adult (17–64 years):

Typical Starting Dose: 20mg once a day orally.

Increase in Dose: Your doctor may increase the dose up to 40mg after 2 weeks.

Children ( 6–16 years):

Dosage is based on weight in this age group.

Typical starting dosage:

Children weighing 44–77 pounds (20–35 kg): 10mg once a day.
Children weighing 77 pounds and above (35 kg and above): 20mg once a day.
Increase in Dose: Your doctor may increase your child’s dosage after 2 weeks, up to 20 mg if they were on 10 mg and up to 40 mg if they were on 20 mg.

Children (0–5 years):

This drug must be avoided in children below 6 years.

Senior dosage (65 years and older):

In older adults, the dose of the drug needs to be reduced, or given at a different schedule because older adults eliminate drugs more slowly. Olmesartan causes the accumulation of medicine in the body. Your doctor may keep you on a lower dose or a different schedule if you are an older person.

Special Considerations:

Kidney Impairment: If you have any kidney problem, your doctor may start a lower dosage of this drug.

Oral Suspension: If your child is unable to swallow a tablet, request your pharmacist to prepare an oral suspension using the tablets.

Most common questions asked about Olmesartan / Q&A’s:

What are the symptoms of Olmesartan overdose?

Olmesartan overdose symptoms may include dizziness, fainting, fast or slow heartbeat. Seek a medical emergency as soon as possible if you experience any of these symptoms.


TheMedPharma has made every effort to make sure that all the information is factually correct, comprehensive, and up-to-date. However, this website should not be considered as a substitute for the advice, knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or licensed health care professional before taking any medication. The drug information contained herein is subjected to changes if required. The lack of warnings or other information for a given drug does not mean that the drug or its combination is safe, effective or appropriate for use in all patients.