Olmesartan and Hydrochlorothiazide (Oral)

Olmesartan and Hydrochlorothiazide is a combination drug that is used in the treatment of high blood pressure. Lowering your blood pressure reduces your risk of a stroke or heart attack.


Olmesartan and hydrochlorothiazide is a drug combination is used either in conjunction with other medications or alone to treat high blood pressure. Hypertension e adds to the workload of the arteries and heart. If this continues for a long time, the arteries and heart may not function correctly. This can then damage the blood vessels of the heart, brain, and kidneys which will result in heart failure, a stroke, or kidney failure. If you lower your blood pressure, it can reduce the risk of heart attacks and strokes.

Olmesartan is an angiotensin II receptor blocker. This works by blocking a substance in the body that tightens the blood vessels. Olmesartan relaxes the blood vessels as a result of this which lowers blood pressure and increases the supply of oxygen and blood to the heart.

Hydrochlorothiazide is a water pill (thiazide diuretic). It works by reducing the level of water in the body by increasing the flow of urine, which in turn helps lead to lower blood pressure.

You can only obtain this medication with a prescription from your doctor and it is available in the dosage form of a tablet.

Conditions treated

  • High blood pressure

Type of medication

  • Oral tablet

Side effects

Along the intended effects of this drug combination, its use could produce some unwanted side effects. Whilst not all of these side effects may be present, if they do occur, you may need to seek medical attention.

You should seek advice from a healthcare professional if you suffer from any of the following side effects whilst taking Olmesartan and Hydrochlorothiazide:

Less common

  • Increased hunger


  • Puffiness or swelling of the face

Incidence not known

  • Convulsions

Most of the side effects that you suffer from won't require medical attention. You typically find that these side effects begin to reduce as your body starts adjusting to the medication. You can seek advice from your local pharmacist or a healthcare professional on ways to reduce the intensity of these side effects. You should check with your doctor if any of the following side effects listed belong, become persistent or bothersome.

More common

  • Ear congestion or pain

Less common

  • Joint pain, swelling, or stiffness

Incidence not known

  • Nervousness

You may suffer from other side effects that are not listed above. You should seek advice from your doctor if you notice anything unusual. If you wish, you can report all side effects to the FDA. You can contact them at 1-800-FDA-1088.


The final dose of this medication will depend on individual circumstances such as your weight, age and height, any other medical conditions you suffer from and any other medications you are currently taking. Your doctor will also take into account the strength of the medication, how long you will be taking the medication and your reaction to the first dose. It's important that you do not change your dose without speaking with your doctor first. If you take too much of this drug it could produce side effects and if you take too little it could reduce the effectiveness of your treatment. Do not share your medication with anyone else. The following doses are guidelines only and your final dose may be different.

For oral dosage form (tablets) for the treatment of high blood pressure.

Adults: You should take one tablet each day. Your healthcare team can adjust your dose if necessary.

Children: The final dose and use will be determined by your doctor.

Missed Dose

If you miss a dose of Olmesartan and Hydrochlorothiazide, you need to take it as soon as you remember. This is unless it's close to the next of your next scheduled dose. In this case, you should skip the dose you have missed and revert back to the original schedule you take your dues. Don't double your doses.

Proper Use

You can take this medication with or without the consumption of food.

If you are also using colesevelam, you should take it at least four hours after taking Benicar HCT®.


Interactions can occur with this drug combination with various other medications. This could lead to severe side effects or even reduce the effectiveness of your drug in treatment. To help reduce the risk of these interactions occurring, you should make your health care team aware of all the current and past medications you are taking. This should include herbal products, vitamin supplements and prescription and nonprescription drugs. You should also make your health care team aware of any other medical conditions you may suffer from. In most cases, your doctor will avoid treating you with this drug when possible, but in other cases, it may still be the best treatment plan for your despite the risk of interactions.

The use of this medication alongside any of the following medications is not recommended. Your doctor may avoid treating you with this drug or change some of the other medications you take.

  • Dofetilide

The use of this medication alongside any of the following medications is not typically recommended. However, it may be required in some cases. If you are given both drugs at the same time, your doctor may alter the dose or frequency in which you use either medication.

  • Ketoprofen

The use of this medication alongside any of the following drugs may increase your risk of certain side effects, however, both may be the best treatment plan for you. If you are given both medications at once, your doctor Amy change your dose or how often you use either medication.

  • Topiramate

Let your doctor know if you are taking any of the following drugs:

  • Dalteparin

Other Interactions

Some medications cannot be used when consuming food or certain types of food. The use of tobacco and alcohol can increase interactions. You should discuss with your doctor about the use of food, alcohol, and tobacco with this medication.

Other Medical Problems

The presence of other medical conditions can affect the use of this medication. Ensure you let your doctor know if you have any other medical conditions, especially:

  • Hyperuricemia (high uric acid in the blood)



Let your healthcare team know if you've ever suffered from an allergic reaction this drug or any other medications. You should also make them aware of any other allergies you may suffer from including animals, foods, preservatives or dyes.

Pediatric population

Appropriate studies have not been conducted on the relationship of age to the effects of olmesartan and hydrochlorothiazide combination in the younger population. Therefore efficacy and safety have not been established.

Geriatric population

Appropriate studies conducted to date have not indicated a geriatric-specific problem that could limit the effectiveness of olmesartan and hydrochlorothiazide combination in the elderly population. However, older patients are more likely to have age-related liver, kidney, or heart problems, which could require a degree of caution and an adjustment in the dose for those who are receiving this drug combination.

Use in pregnancy and breastfeeding

This drug combination is under FDA pregnancy category D. Don't take this drug combination if you are pregnant. The use of this drug could produce birth defects in the baby or loss of the infant. If you fall pregnant whilst on this drug, you need to contact your healthcare team immediately. You should contact your doctor if you are breastfeeding. It's best to avoid breastfeeding whilst using this drug combination.

It's extremely important that your doctor monitors your progress at regular appointments to ensure this medication is working correctly. Your doctor may conduct urine and blood tests to test for unwanted side effects.

Fainting, dizziness, or lightheadedness can also occur, especially when you get up suddenly from a sitting or lying position. Ensure you know how you react to the medication before you user machinery, drive, or do other things that could be dangerous if you are feeling dizzy. If you feel dizzy, you should sit for a few moments before standing.

Check with your doctor immediately if you become sick while taking this medication, especially with severe or continuing vomiting, nausea, or diarrhea that doesn't stop. These conditions could cause you to lose too much salt or water and lead to low blood pressure. You can also lose water via sweating, so it's important to drink plenty of water in hot weather or during exercise.

Chronic diarrhea coupled with weight loss could develop months to years after taking this medication. You should inform your healthcare professional immediately if you suffer from these symptoms.

Contact your healthcare team immediately if you suffer from difficulty with reading, blurred vision, eyes pain or other vision changes. This could be a sign of serious eye problems. Your doctor may request for you to see an eye doctor.

This medication can affect blood sugar levels. Those who suffer from type 1 or type 2 diabetes may notice a change in the results of urine or blood tests. You should speak with your doctor if you have any problem or questions.


You should store Olmesartan and Hydrochlorothiazide in a closed container at room temperature, kept away from moisture, heat and direct light. Don't let this medication freeze. You should also keep it out of the reach of children. Dispose of any medicine you no longer need or have passed their expiry date. You should seek advice from your local pharmacist for the best method of disposal for this medication.


When used as directed, this drug combination is successful in the treatment of hypertension (high blood pressure). Due to a large number of interactions that can occur with this drug, it's imperative you give your healthcare team a full list of all medications you are taking. The safety and efficacy of this drug have not been established in the use of children. You should let your doctor know if you are pregnant as this drug could cause child loss or birth defects. You should also make your doctor aware if you are currently breastfeeding. You should only take this drug as it has been directed from your doctor or healthcare professional. Changing your dose without advice could lead to further health problems. It's important to let your doctor know if your condition does not begin to improve. Your doctor will monitor your blood pressure whilst on this medication to ensure it is working properly. If you require any further information about the practical uses of this drug combination, or you have any questions or queries, you should contact your local healthcare professional or a doctor for more advice.