ACE Inhibitors vs. ARBs
- ACE inhibitors (angiotensin converting enzyme inhibitors) and ARBs (angiotensin-receptor blockers) are used to treat high blood pressure (hypertension) and congestive heart failure, to prevent kidney failure in patients with high blood pressure or diabetes, and to reduce the risk of stroke.
- ACE inhibitors are also used to improve survival after heart attacks.
- ARBs are also used to prevent diabetes and may prevent the recurrence of atrial fibrillation.
- Examples of ACE Inhibitors include benazepril hydrochloride (Lotensin), captopril (Capoten), enalapril maleate (Vasotec), fosinopril sodium (monopril), lisinopril (Prinivel, Zestril), moexipril (Univasc), moexipril (Univasc), perindopril (Aceon), quinapril hydrochloride (Accupril), ramipril (Altace), and trandolapril (Mavik).
- Examples of ARBs include losartan (Cozaar), valsartan (Diovan), irbesartan (Avapro), candesartan (Atacand), eprosartan mesylate (Teveten), and telmisartan (Micardis).
- Common side effects of ACE inhibitors include:
- Serious side effects of ACE inhibitors include:
- ARBs do not tend to cause cough or angioedema as a side effect. They may cause dizziness.
- Both ACE inhibitors and ARBs are not recommended for use during pregnancy. They may cause low blood pressure, excess potassium in the blood (hyperkalemia), kidney failure, and harm to a fetus.
What are ACE Inhibitors and ARBs?
ACE inhibitors (angiotensin converting enzyme inhibitors) work by preventing a natural body substance called angiotensin I from converting into angiotensin II, which cases blood vessels to narrow and constrict. By preventing this change, the blood vessels remain relaxed and blood pressure decreases.
ARBs (angiotensin-receptor blockers) also affect angiotensin, but they prevent angiotensin II from binding to an area on blood vessels called receptors. They have the same result as ACE inhibitors in that blood vessels remain relaxed and blood pressure decreases.
What are the side effects of ACE inhibitors and ARBs?
ACE inhibitors are well-tolerated by most individuals. Nevertheless, they are not free of side effects, and some patients should not use ACE inhibitors.
Individuals with bilateral renal artery stenosis (narrowing of the arteries that supply the kidneys) may experience worsening of kidney function, and people who have had a severe reaction to ACE inhibitors probably should avoid them.
The most common side effects are:
- Elevated blood potassium levels
- Low blood pressure,
- Abnormal taste (metallic or salty taste)
- Chest pain
- Increased uric acid levels
- Sun sensitivity
- Increased BUN and creatinine levels
It may take up to a month for coughing to subside, and if one ACE inhibitor causes cough it is likely that the others will too. The most serious, but rare, side effects of ACE inhibitors are:
- Kidney failure
- Allergic reactions
- Liver dysfunction
- A decrease in white blood cells
- Swelling of tissues (angioedema).
ARBs are well tolerated by most individuals. The most common side effects are
- elevated potassium levels in the blood (hyperkalemia),
- low blood pressure,
- abnormal taste sensation (metallic or salty taste),
- orthostatic hypotension (low blood pressure upon standing),
- indigestion, and
- upper respiratory tract infection.
Compared to ACE inhibitors, cough occurs less often with ARBs.
Serious side effects of ARBs:
- The most serious, but rare, side effects are
- kidney failure,
- liver failure (hepatitis),
- serious allergic reactions,
- a decrease in white blood cells,
- a decrease in blood platelets, and
- swelling of tissues (angioedema).
- There have been reports of rhabdomyolysis (destruction of skeletal muscle) in patients receiving ARBs.
- Individuals who have narrowing of both arteries that supply the kidneys or have had a severe reaction to ARBs should avoid them.
- Like other antihypertensives, ARBs have been associated with sexual dysfunction.
What drugs interact with ACE inhibitors and ARBs?
ACE inhibitors have few interactions with other drugs.
- Since ACE inhibitors may increase blood levels of potassium, the use of potassium supplements, salt substitutes (which often contain potassium), or other drugs that increase the body's potassium may result in excessive blood potassium levels.
- ACE inhibitors also may increase the blood concentration of lithium (Eskalith, Lithobid) and lead to an increase in side effects from lithium.
- There have been reports that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Advil, Children's Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever etc.), indomethacin (Indocin, Indocin-SR), and naproxen (Anaprox, Naprelan, Naprosyn, Aleve) may reduce the blood pressure lowering effects of ACE inhibitors.
- Patients receiving diuretics may experience excessive reduction in blood pressure when ACE inhibitors are started. Stopping the diuretic or increasing salt intake prior to taking the ACE inhibitor may prevent excessive blood pressure reduction. Close supervision for at least two hours after the start of ACE inhibitors and until blood pressure is stable is recommended if the diuretic cannot be stopped.
- ACE inhibitors should not be combined with ARBs because such combinations increase the risk of hypotension, hyperkalemia, and renal impairment.
- Ace inhibitors should not be combined with aliskiren (Tekturna), another class of drugs that is used to treat high blood pressure because such combinations increase the risk of kidney failure, excessive low blood pressure, and hyperkalemia.
- Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and low blood pressure) may occur when injectable (gold sodium aurothiomalate [Myochrysine]), used in the treatment of rheumatoid arthritis, is combined with ACE inhibitors.
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.
- ARBs may also increase the blood concentration of lithium (Eskalith, Lithobid) and lead to an increase in side effects from lithium.
- Rifampin (Rifadin) reduces the blood levels of losartan, and fluconazole (Diflucan) reduces the conversion of losartan to its active form. These effects could decrease the effects of losartan.
- ARBs should not be combined with ACE inhibitors because such combinations increase the risk of hypotension, hyperkalemia, and renal impairment.
- ARBs should not be combined with aliskiren (Tekturna) because such combinations increase the risk of kidney failure, excessive low blood pressure, and hyperkalemia.
What are the different types of ACE inhibitors and ARBs?
The following is a list of the ACE inhibitors that are available in the United States:
- benazepril (Lotensin)
- captopril (Capoten- discontinued brand)
- enalapril (Vasotec, Epaned, [Lexxel- discontinued brand])
- fosinopril (Monopril- Discontinued brand)
- lisinopril (Prinivil, Zestril, Qbrelis)
- moexipril (Univasc- Discontinued brand)
- perindopril (Aceon)
- quinapril (Accupril)
- ramipril (Altace)
- trandolapril (Mavik)
The following is a list of currently available ARBs:
- azilsartan (Edarbi)
- candesartan (Atacand),
- eprosartan (Teveten),
- irbesartan (Avapro),
- telmisartan (Micardis),
- valsartan (Diovan),
- losartan (Cozaar), and
- olmesartan (Benicar).