Olmesartan medoxomil

Olmesartan medoxomil is a drug used to treat high blood pressure (hypertension). It is a type of drug called an angiotensin II receptor blocker. It may be used alone or with other drugs to treat high blood pressure.

Its brand name is Benicar, and it was patented by Sankyo Pharma, Inc. It was approved by the FDA on April 25, 2002.

The aorta (main artery exiting the heart) and its branches. Source: Gray's Anatomy.)

Hypertension

When the heart beats, it pumps blood to the arteries and creates pressure in them. This pressure (blood pressure) results from the pumping of blood into the arteries, as well as the resistance to the blood flow by the arteries. Healthy arteries are muscular and elastic and therefore stretch when the heart pumps blood through them. Normally, your heart beats about 60 to 80 times a minute. Normal blood pressure should normally be less than 120/80 mm Hg (millimeters of mercury) for an adult. Blood pressure that stays between 120–139/80–89 is considered prehypertension and above this level (140/90 mm Hg or higher) is considered high (hypertension).

High blood pressure can occur in children or adults, but it's more common among people over age 35. Hypertension is most common in:

• African Americans
• middle-aged and elderly people
• obese people
• heavy drinkers
• diabetics
• people with kidney disease

How It Works

Olmesartan belongs to a class of drugs known as angiotensin II (A2) receptor blockers (ARBs). These medicines are closely related to the common medications known as ACE inhibitors, which block an enzyme in the body that is responsible for causing the blood vessels to narrow. If the blood vessels are relaxed, the blood pressure is lowered and more oxygen-rich blood can reach the heart. ACE inhibitors inhibit an enzyme called angiotensin converting enzyme (ACE), that is responsible for converting angiotensin I to A2. A2 causes constriction of arteries, causing an increase in blood pressure. It also causes the release of aldosterone, which causes the body to retain salt and water, increasing blood pressure. A2 receptor blockers like olmesartan, however, do not inhibit ACE. Rather, they block the binding of A2 to its receptor in many tissues, including vascular smooth muscle (for example, heart muscle), and the adrenal glands. Binding of a protein to its receptor is essential for it to work, so the blockage of this decreases the actions of A2 (blood vessel constriction and release of aldosterone).

Risks

Interactions

• When taken together with digoxin, olmesartan can raise the amount of digoxin in the blood. Patients who are taking digoxin will need periodic blood tests to monitor blood digoxin levels, and the dose may need to be adjusted.
• Concurrent treatment with potassium supplements, ACE inhibitors, and certain kinds of diuretics known as potassium-sparing diuretics increases the risk of high blood levels of potassium (hyperkalemia), which can be dangerous.
• People being treated with diurectics (water pills) should watch for signs of low blood pressure, such as dizziness or fainting. They should notify a physician if they experience these signs; they may need dose adjustments.

Overdose

Signs and symptoms of olmesartan overdose include:

• decreased blood pressure
• dizziness
• increased heart rate

Precautions

• Olmesartan should not be taken in pregnancy, except in extremely rare cases. Taking olmesartan or similar drugs during the second and third trimesters of pregnancy may cause harm and even death to the unborn fetus. These effects do not appear to happen if olmesartan or or similar drugs are taken only during the first trimester. Infants who have been exposed to olmesartan while in the uterus should be closely monitored.
• Breastfeeding while on olmesartan is not recommended, as the drug does enter breast milk.
• Kidney disease, liver disease, high blood levels of potassium, heart problems, or severe dehydration may affect whether it is safe to take olmesartan, and the physician should be notified.
• Olmesartan should be avoided in patients who are allergic to olmesartan or to any of the ingredients in olmesartan.

Side Effects

This is not a complete list of side effects reported with olmesartan.

When side effects occur they are generally mild and do not last long. Some possible side effects include:

• Dizziness
• Flu-like symptoms
• Upper respiratory infection
• Back pain
• Sinusitis
• Diarrhea
• Sore throat/pharyngitis

How Olmesartan is Taken

Olmesartan may be taken without regard to food. It should be taken at approximately the same time each day.

Alternatives

There are several treatment options for hypertension.

• Lifestyle modification:
  

This includes things such as decreased salt intake, exercise, moderate alcohol consumption, and weight loss. These conservative measures can make a significant impact on blood pressure, and should be used in combination with any drug treatment. They generally should be used alone only in the prevention of hypertension and in mild hypertension.

• Diuretics:
  

Examples include: chlorthalidone (Hygroton), hydrochlorothiazide (Hydrodiuril, Microzide, Esidrix), indapamide (Lozol), metolazone (Mykrox, Zaroxolyn), bumetanide (Bumex), ethacrynic acid (Edecrin), furosemide (Lasix), torsemide (Demadex), amiloride hydrochloride (Midamor), spironolactone (Aldactone), triamterene (Dyrenium)

• Beta-blockers:
  

Examples include: acebutolol (Sectral), atenolol (Tenormin), betaxolol (Kerlone), bisoprolol fumarate (Zebeta), carteolol hydrochloride (Cartrol), metoprolol tartrate (Lopressor), metoprolol succinate (Toprol-XL), nadolol (Corgard), penbutolol sulfate (Levatol), pindolol (Visken), propranolol hydrochloride (Inderal, Inderal LA), timolol maleate (Blocadren)

• Calcium channel blockers:
  

These include diltiazem hydrochloride (Cardizem SR, Cardizem CD, Dilacor XR, Tiazac), verapamil hydrochloride (Isoptin SR, Calan SR Verelan, Covera HS), amlodipine besylate(Norvasc), felodipine (Plendil), isradipine (DynaCirc, DynaCirc CR), nicardipine (Cardene SR), nifedipine (Procardia XL, Adalat CC), nisoldipine (Sular)

• ACE inhibitors:
  

Examples include: quinapril (Accupril), perindopril (Aceon), ramipril (Altace), captopril (Capoten), benazepril (Lotensin), trandolapril (Mavik), fosinopril (Monopril), lisinopril (Prinivil), lisinopril with a diuretic (Prinzide), moexipril (Univasc), enalapril with a diuretic (Vaseretic), enalaprilat or enalapril (Vasotec), lisinopril with a diuretic (Zestoretic), lisinopril (Zestril)

• Other A2 receptor blockers:
  

Examples include: candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro), losartan (Cozaar), telmisartan (Micardis), valsartan (Diovan)

Research

A review of seven trials with olmesartan showed that it offers double-digit reductions in systolic and diastolic blood pressures at both dosages. Further, comparison shows that olmesartan is better than the other ARBs losartan, valsartan, and irbesartan in treating blood pressure.^[1]

A 2005 meta-analysis (a study that summarizes results of several previous studies) included results from three studies looking at ARBs. In two of the three studies, an ARB decreased stroke compared to either placebo or an ACE inhibitor. Compared to other antihypertensive drugs, ARB treatment was associated with no significant change in mortality from all sources. There was an increase in heart attack, but this was partly offset by a decrease in new-onset diabetes.^[2]

Clinical Trials

ACCORD-Action to Control Cardiovascular Risk in Diabetes

ALLHAT-The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

Framingham Heart Study

For an extensive list of completed, ongoing, and upcoming clinical trials related to Benicar, go to ClinicalTrials.gov

References

• Lexi-comp Drug Information Handbook, 12th edition.
• Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. National Heart Lung and Blood Institute.

1. ↑ Greathouse M. A review of olmesartan medoxomil monotherapy: antihypertensive efficacy similar to that of other angiotensin II receptor blocker/hydrochlorothiazide combinations? Congest Heart Fail. 2002 Nov-Dec;8(6):313-20. Abstract
2. ↑ Cheung BM, Cheung GT, Lauder IJ, Lau CP, Kumana CR. Meta-analysis of large outcome trials of angiotensin receptor blockers in hypertension. J Hum Hypertens. 2006 Jan;20(1):37-43. Abstract

External Links

American Heart Association- Hypertension

Official Benicar Website

WebMd Patient Information on Benicar