captopril (Capoten)

What is captopril, and how does it work (mechanism of action)?

Captopril is an oral drug and a member of a class of drugs called angiotensin converting enzyme (ACE) inhibitors. ACE inhibitors are used for treating high blood pressure, heart failure, and for preventing kidney failure due to high blood pressure and diabetes. Other ACE inhibitors include enalapril (Vasotec), quinapril (Accupril), ramipril (Altace), fosinopril (Monopril), benazepril (Lotensin), lisinopril (Zestril, Prinivil), moexipril (Univasc) and trandolapril (Mavik).

Angiotensin II is a very potent chemical that causes the muscles surrounding blood vessels to contract, thereby narrowing the vessels. The narrowing of the vessels increases the pressure within the vessels causing high blood pressure (hypertension). Angiotensin II is formed from angiotensin I in the blood by the enzyme angiotensin converting enzyme or ACE. ACE inhibitors are medications that slow (inhibit) the activity of the enzyme ACE and decrease the production of angiotensin II. As a result, blood vessels enlarge or dilate, and blood pressure is reduced. The lower blood pressure makes it easier for the heart to pump blood and can improve the function of a failing heart. In addition, progression of the disease in the blood vessels within the kidney caused by high blood pressure or diabetes is slowed. The FDA approved captopril in April 1981.

What brand names are available for captopril?

Capoten

Is captopril available as a generic drug?

GENERIC AVAILABLE: Yes

Do I need a prescription for captopril?

Yes

What are the side effects of captopril?

Captopril generally is well tolerated, and side effects are usually mild and transient. A dry, persistent cough has been reported commonly with the use of captopril and other ACE inhibitors. Coughing resolves after discontinuing the drug. Other side effects include abdominal pain, constipation, diarrhea, rash, dizziness, fatigue, headache, loss of taste, loss of appetite, nausea, vomiting, fainting and numbness or tingling in the hands or feet.

Captopril and other ACE inhibitors also may cause kidney failure and increased levels of potassium in the blood. Serious but, fortunately, very rare side effects are liver failure and angioedema (swelling of lips and throat that can obstruct breathing).

SLIDESHOW

How to Lower Blood Pressure: Exercise and Tips See Slideshow

What is the dosage for captopril?

  • The recommended dose of captopril for treating hypertension in adults is 25-150 mg two or three times daily.
  • The maximum dose is 450 mg daily. The dose for treating heart failure is 6.25 to 12.5 mg every 8 hours.
  • The target dose is 50 mg every 8 hours and the maximum dose is 450 mg daily.
  • The dose for diabetic nephropathy is 25 mg every 8 hours.
  • It should be taken on an empty stomach one hour before or two hours after meals since absorption of captopril is reduced when it is taken with food.

Which drugs or supplements interact with captopril?

: The use of ACE inhibitors with potassium supplements, salt substitutes or diuretics, for example, spironolactone (Aldactone), that increase potassium in the blood may lead to excessive potassium levels (hyperkalemia). Potassium levels should be monitored whenever ACE inhibitors are used in combination with these drugs.

There have been reports of increased lithium (Eskalith, Lithobid) levels when lithium is used in combination with ACE inhibitors. The reason for this interaction is not known, but the increased levels may lead to toxicity from lithium.

There have been reports that aspirin and other nonsteroidal antiinflammatory 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 effects of ACE inhibitors.

Combining captopril or other ACE inhibitors with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients who are elderly, volume-depleted (including those on diuretic therapy), or with poor kidney function may result in reduced kidney function, including kidney failure. These effects are usually reversible.

Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and low blood pressure) may occur when injectable gold (sodium aurothiomalate), used in the treatment of rheumatoid arthritis, is combined with ACE inhibitors, including captopril.

Is captopril safe to take if I'm pregnant or breastfeeding?

Captopril is secreted in breast milk. Therefore it should be avoided by nursing mothers.

What else should I know about captopril?

What preparations of captopril are available?

Tablets: 12.5, 25, 50, and 100 mg

How should I keep captopril stored?

Captopril should be stored at room temperature, 15 C to 30 C (59 F to 86 F) and away from moisture.

Summary

Captopril (Capoten) is an ACE inhibitor prescribed for the treatment of high blood pressure, heart failure, and prevention of kidney failure due to high blood pressure and diabetes. Side effects, drug interactions, warnings and precautions, and efficacy during pregnancy information should be reviewed prior to taking this medication.

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See more info: captopril on RxList
References
Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine

REFERENCE:

FDA Prescribing Information