Angiotesin II Receptor Blockers (ARBs) Angiotensin II receptor blockers (ARBs) help relax blood vessels. This effect lowers the blood pressure and makes it easier for the heart to pump blood. How does an Angiotensin II Receptor Blocker (ARB) work? Angiotensin II is a natural substance in the body that affects cardiovascular system in many ways, such as by narrowing blood vessels. This narrowing can increase blood pressure and force the heart to work harder. Angiotensin II also starts the release of a hormone that increases the amount of sodium and water in the body, which can lead to an increase in blood pressure. Angiotensin II can also thicken and stiffen the walls of blood vessels and heart. ARBs blocks the action of angiotensin II which allows blood vessels to widen (dilate). What are the different types of ARBs? Several ARBs are available. Many seem to work equally as well. Your physician will prescribe what he/she thinks will work best for your condition based on experience. ARBs, at the present time, are generally prescribed when you cannot tolerate an ACE inhibitor. Examples of ARBs include: Candesartan (Atacand) Eprosartan (Teveten) Irbesartan (Avapro) Losartan (Cozaar) Olmesartan (Benicar) Telmisartan (Micardis) Valsartan (Diovan) For what conditions are ARBs used? Doctors prescribe these drugs to prevent, treat or improve symptoms in a variety of conditions, such as: High blood pressure Heart failure Kidney failure in diabetes Chronic kidney diseases (Primary Nephrotic Syndrome) Hardening and thickening of the skin (scleroderma) ARBs are regularly prescribed for patients diagnosed with primary (idiopathic) Nephrotic Syndrome in order to manage high blood pressure as a result of a problem with your kidneys that can lead to fluid retention or overload. Since these medications have effects that are similar to those of ACE inhibitors, they often are used when ACE inhibitors are not tolerated by patients (for example, due to excessive coughing). What are the side effects of ARBs? Few people have side effects when taking ARBs, but possible side effects may include: Headache Dizziness Lightheadedness Nasal congestion Back and leg pain Diarrhea Rare but more serious side effects include: Kidney failure Liver failure Allergic reaction A drop in white blood cells Localized swelling of tissues (angioedema) Because ARBs can cause birth defects, don’t take them if you are pregnant or plan to become pregnant. Cough is less common with ARBs than with ACE Inhibitors. In general, ARBs cause fewer side effects than ACE inhibitors. If you have side effects, it’s important to talk to your doctor or the healthcare professional who prescribed your medicine before you stop taking it. Are there any differences among the different types of ARBs? Most ARBs are similar in actions and side effects, but they do differ in how they are eliminated from the body and how they are distributed throughout the body. Some ARBs are better at lowering blood pressure than others. In some studies, irbesartan (Avapro) and candesartan (Atacand) reduced blood pressure better than losartan (Cozaar). How are ARBs administered? ARBs can be taken on an empty or full stomach. ARBs are only available by prescription from a doctor. They usually come as tablets, which you take once a day. Follow the label directions on how often to take this medication. The number of doses you take each day, the time allowed between doses, and how long you need to take the medication will depend on the type of ARB prescribed, as well as your condition. It may take many weeks for you to feel the full effects of the medication. While taking this medication, have your blood pressure and kidney function checked regularly, as recommended by your doctor. With which drugs do ARBs interact? ARBs have few interactions with other drugs. Since ARBs may increase blood levels of potassium, the use of potassium supplements, salt substitutes (which often contain potassium), or other drugs that increase potassium may result in excessive blood potassium levels and cardiac arrhythmias (irregular heartbeat). *Note: The decision to prescribe a medication is the responsibility of your physician/primary care provider based on his/her evaluation of your condition. The above is meant for informational purposes only. Discuss this information and all information about drugs/medications with your physician before starting or stopping any medication.