1. Home
  2. >
  3. Blog
  4. >

Olmesartan medoxomil – Uses, precautions, side effects

by egpat         29 May 2024

Blood pressure is one of the essential conditions for maintaining daily activities, but when this blood pressure is elevated, it may lead to many types of cardiovascular complications. The elevated levels of blood pressure may encourage the formation of atherosclerosis in those patients with elevated levels of cholesterol. In atherosclerosis, the blood vessels are blocked, resulting in the development of stroke or cardiovascular complications like tachycardia, atrial fibrillation, and finally myocardial infarction. So all these cardiovascular complications are linked to an elevation of blood pressure.

The blood pressure can be controlled by so many types of drugs, and one group of drugs acts on the renin-angiotensin-aldosterone system (RAS). even though it is primarily linked with the renal system, and many of the organs are linked with RAS. Lungs play an important role by producing the angiotensin-converting enzyme (ACE) enzyme. The kidney is another organ that is going to produce renin as an enzyme, and the liver is the third organ that is going to produce the precursor for the angiotensin system.

In the liver, one of the precursors that is going to be produced is angiotensinogen. This angiotensinogen can be converted into angiotensin-1 by renin. Kidneys produce this renin, which is going to convert the angiotensinogen into angiotensin-I. Now this angiotensin-I is further converted by another enzyme, ACE, angiotensin-converting enzyme produced from the lungs. Through this conversion, they produce one of the mediators, angiotensin II, which targets blood vessels, leading to vasoconstriction. This increases the blood pressure. That's why one of the targets for controlling blood pressure is to inhibit the activity of the renin-angiotensin system.

Sartans are one group of drugs that act on RAS. These sartans can block the renin-angiotensin system by antagonizing the angiotensin receptors. So they are commonly called angiotensin receptor blockers (ARBs). Olmesartan has the suffix -sartan, which is an ARB angiotensin receptor blocker. This drug is available as an ester, olmesartan medoxomil, which can be given either alone to control the blood pressure or combined with a few of the diuretics like chlorthalidone or hydrochlorthiazide.

Precautions while taking olmesartan

Olmesartan can be given to pediatric patients, but to children under the age of one year, it should not be given. During the first year, organs are going to develop, and as this olmesartan acts on the renin-angiotensin system, it can affect the functionality of the renal system in infants. Therefore, in pediatrics with an age less than one year, if this olmesartan is given, it can impair renal activity, resulting in the immature development of the kidneys. That's why this drug should not be given to children under the age of one year. Even though this drug is safe for children aged 6 to 16 years, for those under the age of six, it is not preferred.

Olmesartan should not be used in pregnant women because it can affect the development of the fetus. Particularly, olmesartan should not be administered in the second and third trimesters of pregnancy. This drug is teratogenic, and it can produce fetal damage, leading to fetal renal failure and fetal lung hypoplasia, decreased development of the lungs, fetal hypotension, and skeletal deformities. Even this drug can reduce amniotic fluid, resulting in miscarriage. Due to all these effects, olmesartan should be avoided by pregnant women.

This drug reduces the blood pressure, resulting in hypotension. When this drug is co-admistered with other drugs, such as diuretics, it can again produce hypotension. Drugs like loop diuretics can produce significant hypotension, so when they are combined with olmesartan, they can produce severe hypotension, which should be avoided.

Olmesartan should be carefully given to those patients who are salt depleted or who are already suffering from hypotension due to loss of minerals, dehydration, or diarrhea. In such conditions, this drug may further increase hypotension.

It may develop acute renal failure, resulting in a few of the symptoms, such as oligourea leading to decreased urinary output, azotemia decreasing blood urea nitrogen, and even hyperkalemia. All these effects are observed with olmesartan on long-term use because of reduced renal functionality. Renal functionality should be measured after very long-term treatment with olmesartan.

Side effects

One of the important side effects of this drug is dizziness, which is commonly observed in many of the patients, and it can also produce some back pain and some diarrhea. Other side effects mainly include headaches, rhinitis, and sinusitis. Some lack of energy can be observed with this olmesartan.

Dosage forms

This drug is available as a tablet in different strengths, such as 5 mg, 20 mg, and 40 mg. The dose of olmesartan depends on many factors. Typically, the initial dose is started at 20 mg per day, given once daily. The dose can also be increased up to 40 mg based on the efficacy of the treatment after two weeks. However, in children, the dose is fixed based on the body weight.


Olmesartan is an imidazole-containing angiotensin receptor blocker. This drug blocks angiotensin II receptor subtype 1, thereby inhibiting vasoconstriction and resulting in vasodilitation. This reduces the blood pressure. This drug can be given in an ester form, such as olmesartan medoxomil, which can be given either alone or in combination with a few of the diuretics, such as hydrochlorthiazide or chlorthalidone. Olmesartan should not be given to children under the age of less than one year, and it is strictly contraindicated for pregnant women. This drug can be given to children aged 6 to 16 years to control their blood pressure. Dizziness, diarrhea, and back pain are the important side effects produced by this drug.