Drug Comparisons

The Angiotensin II Receptor Blockers (ARBs) are a newer class of drugs most commonly used to treat hypertension (high blood pressure). They are also being studied for use in treating patients with heart failure. ARBs block a hormone in the body called angiotensin II. Angiotensin II causes blood vessels to constrict, making it more difficult for the heart to pump blood through the blood vessels. By blocking angiotensin II, ARBs help relax and dilate (or open) the blood vessels, which then lowers blood pressure and decreases the heart's workload, two important goals of treating heart failure. ARBs are generally used to treat heart failure only in patients who are intolerant to a related class of drugs, the ACE inhibitors.

Drugs in this Class
Candesartan ( Atacand )
Eprosartan Tablets ( Eprosartan Mesylate Tablets, Teveten Tablets )
Irbesartan ( Avapro )
Losartan ( Cozaar )
Olmesartan Tablets ( Benicar Tablets, Olmesartan Medoxomil Tablets )
Telmisartan ( Micardis )
Valsartan ( Diovan )

Summarizing the Evidence

• Each drug in this class has been studied to varying degrees for its use in the treatment of heart failure except for the newest ARB, olmesartan. Losartan has been shown in one study to be similar to captopril (an ACE-Inhibitor--considered a first-line therapy for heart failure) with regards to decreasing the number of deaths. Valsartan has been shown in one study to decrease the number of hospitalizations in people with heart failure. Irbesartan has some published scientific evidence that shows it to be similarly effective as lisinopril (an ACE-Inhibitor--considered a first-line therapy for heart failure) in improving exercise tolerance in persons with heart failure. Candesartan has been shown in one study to be similarly effective as enalapril (an ACE-Inhibitor--considered a first-line therapy for heart failure) in decreasing the number of deaths and hospitalizations. In a more recent study, candesartan was shown to reduce the number of cardiovascular-related deaths and hospitalizations from heart failure when compared to placebo. A 2007 study found that eprosartan, telmisartan, or candesartan when added to diuretics, ACE-inhibitors, and beta-blockers improved the heart's output in people with heart failure. Other than this study, eprosartan and telmisartan have limited study evidence in individuals with heart failure.

• While most of the ARBs have been studied for their use in heart failure, valsartan and candesartan are the only ARBs that are FDA-approved for the treatment of heart failure. Valsartan and candesartan are approved for patients who cannot tolerate a first-line ACE-Inhibitor drug. Even though the other ARBs have not received FDA-approval for the treatment of heart failure, they are often used when a patient cannot tolerate a first-line ACE-Inhibitor drug or can possibly be used in combination with an ACE-Inhibitor, although the effectiveness and safety of combined use is still controversial.

• Clinical studies between the drugs in this class that compare their effectiveness for treating heart failure are lacking at this time. All ARBs are thought to work in the same manner in heart failure; therefore, the choice of which ARB is used will depend on your doctor's preference and/or your prescription benefits formulary. However one small study done in 2007 looked at people with heart failure that were over 65 years of age and found that losartan had worse survival rates than irbesartan, valsartan, and candesartan. The study was not the best type of study because it looked back at people's health records to determine its information instead of following individuals forward in time and the majority (61%) of people were taking one drug (losartan). Therefore, larger, more controlled studies need to be done to determine if their is a difference between these drugs.

• ARBs are generally well tolerated with mild side effects such as fatigue, dizziness, diarrhea, upper respiratory tract infection, lightheadedness, and headache. According to clinical trial data, the frequency of side effects among the ARBs is similar.

Dosing and Administration

• Candesartan, eprosartan, irbesartan, olmesartan, telmisartan, and losartan are typically dosed once daily; valsartan is typically dosed twice daily.

Generic Availability

• No drugs in this class are currently available in generic formulations. Losartan (Cozaar) is the oldest drug in this class and will most likely be the first of the ARBs to become available generically.

Drug Interactions

Some interactions between medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals. For specific information on how the drugs interact and the severity of the interaction, please use our Drug Interactions Checker.

Side Effects

To view specific side effect information, please use our Side Effect Checker.

Additional Information

1. Cozaar [package insert]. Whitehouse Station, NJ: Merck & Co, Inc.; Last updated: September 21, 2006.
2. Diovan [package insert]. East Hanover, NJ: Novartis Pharmaceutical Co; Last updated: November 29, 2007.
3. Avapro [package insert]. New York, NY: Bristol-Myers Squibb Sanofi-Synthelabo Partnership; Last updated: April 2007.
4. Atacand [package insert]. Wilmington, DE: AstraZeneca; Last updated: August 17, 2006.
5. Micardis [package insert]. Ridgefield, CT: Boehringer Ingelheim; Last updated: February 7, 2007.
6. Teveten [package insert]. Morrisville, NC: Biovail Pharmaceuticals; Last updated: October 16, 2003.
7. Benicar [package insert]. New York, NY: Sankyo Pharmaceuticals. Last updated: September 26, 2007.
8. Hyzaar [package insert]. Whitehouse Station, NJ: Merck & Co, Inc; Last updated: December 21, 2006.
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Last Updated: April 2008
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