Heart Disease: Heart Disease Medicine: Angiotension II Receptor Blockers

Angiotensin II receptor blockers (ARBs) have the same effects as ACE inhibitors, but work by a different mechanism. These heart medications decrease certain chemicals that narrow the blood vessels, allowing blood to flow more easily through your body. They also decrease certain chemicals that cause salt and fluid build-up in the body. Examples of ARBs include:

• Cozaar (losartan)
• Diovan (valsartan)
• Avapro (irbesartan)
• Atacand (candesartan)
• Micardis (telmisartan)

For What Conditions Would I Be Prescribed an ARB?

ARBs, at the present time, are generally prescribed only when you cannot tolerate an ACE inhibitor.

How Should I Take ARBs?

Most ARBs can be taken on an empty or full stomach. Ask your doctor or pharmacist for specific instructions. 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. Note: 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.

Should I Avoid Certain Food or Medications?

While taking an ARB, do not use salt substitutes: they contain potassium and this medication can cause the body to retain potassium. Learn how to read food labels to choose low-sodium and low-potassium foods. A dietician can help you.

Over-the-counter nonsteroidal anti-inflammatory medicines (like ibuprofen or naproxen) and aspirin may cause the body to retain sodium and water and decrease the effect of an ARB. Check with your health care provider before taking any anti-inflammatory medications.

Digoxin and warfarin may interfere with the effects of Micardis. If you are taking these medications, tell your doctor before an ARB is prescribed.

It is important that your doctor is aware of all the medications you are taking, as some may have the potential to interact with each other. Talk to your doctor before taking any new medication, including over-the-counter drugs, herbs and supplements.

What Are the Side Effects?

Side effects of taking ARBs include:

• Dizziness, lightheadedness or faintness upon rising. This side effect may be strongest after the first dose, especially if you have been taking a diuretic (water pill). Get up more slowly. Contact your doctor if these symptoms are persistent or severe.
• Diarrhea, muscle cramps or weakness, back or leg pain, insomnia (difficulty sleeping), irregular heartbeat, or fast or slow heartbeat, sinusitis or upper respiratory infection. Contact your doctor if these symptoms are persistent or severe.
• Confusion. Contact your doctor right away.
• Severe vomiting or diarrhea. If you become sick with severe vomiting or diarrhea you may become dehydrated, which can lead to low blood pressure. Contact your doctor.

Contact your doctor if you have any other symptoms that cause concern.

Reviewed by the doctors at The Cleveland Clinic Heart and Vascular Institute (2005).