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Generic name: captopril [ KAP-toe-pril ]
Brand name: Capoten
Dosage form: oral tablet (100 mg; 12.5 mg; 25 mg; 50 mg)
Drug class: Angiotensin Converting Enzyme Inhibitors

Medically reviewed by Sanjai Sinha, MD. Last updated on Aug 22, 2023.

What is captopril?

Captopril is used in adults alone or in combination with other medications to treat high blood pressure (hypertension) and congestive heart failure.

Captopril is also used to improve survival and reduce the risk of heart failure after a heart attack in patients with a heart condition called left ventricular hypertrophy (enlargement of the walls of the left side of the heart). Captopril is also used to treat kidney disease (nephropathy) caused by diabetes in patients with type 1 diabetes and retinopathy (eye disease).

Captopril belongs to a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It decreases certain chemicals that tighten the blood vessels, so blood flows more smoothly and the heart can pump blood more efficiently.


Do not use captopril if you are pregnant. Stop using captopril and tell your doctor right away if you become pregnant.

If you have diabetes, do not use captopril together with any medication that contains aliskiren (Amturnide, Tekturna, Tekamlo).

Tell your doctor about all your other medicines. Some drugs should not be used with captopril.

Before taking this medicine

You should not use this medicine if you are allergic to captopril or to any other ACE (angiotensin converting enzyme) inhibitor such as benazepril, fosinopril, enalapril, lisinopril, moexipril, perindopril, quinapril, ramipril, or trandolapril.

If you have diabetes, do not take captopril with any medication that contains aliskiren (a blood pressure medicine).

Do not take captopril within 36 hours before or after taking medicine that contains sacubitril (such as Entresto).

To make sure captopril is safe for you, tell your doctor if you have ever had:

You may also need to avoid taking captopril with aliskiren if you have kidney disease.

Stop using this medicine and tell your doctor right away if you become pregnant. Captopril can cause injury or death to the unborn baby if you use the medicine during your second or third trimester.

Do not breastfeed.

How should I take captopril?

Take captopril exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Take on an empty stomach, at least 1 hour before a meal.

Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. You can easily become dehydrated while taking captopril. This can lead to very low blood pressure, an electrolyte imbalance, or kidney failure.

Your blood pressure will need to be checked often, and you may need frequent blood tests.

captopril may cause false results on a urine test. Tell the laboratory staff that you use captopril.

Tell your doctor if you have a planned surgery.

If you have high blood pressure, keep using this medicine even if you feel well. High blood pressure often has no symptoms.

Store tightly closed at room temperature, away from moisture and heat.

Dosing information

Usual Adult Dose for Hypertension:

Initial dose: 25 mg orally 2 to 3 times a day one hour before meals

Maintenance dose: May increase every 1 to 2 weeks up to 50 mg orally three times a day. If blood pressure remains uncontrolled after 1 to 2 weeks at this dose, add a thiazide diuretic (loop diuretic if severe renal impairment exists) and titrate to its highest usual antihypertensive dose before further increases of captopril.

Maximum dose: 450 mg/day

Usual Adult Dose for Congestive Heart Failure:

Initial dose: 25 mg orally three times a day (6.25 to 12.5 mg orally three times a day if hypotensive, hyponatremic, or hypovolemic)

Target maintenance dose: 50 mg orally three times a day for at least two weeks to ensure a satisfactory response

Maximum dose: 450 mg/day

-Most patients experience satisfactory clinical improvement at 50 or 100 mg orally three times a day.
-Should generally be used in conjunction with a diuretic and digitalis.

Usual Adult Dose for Left Ventricular Dysfunction:

Initial dose: 6.25 mg orally once as early as three days post-myocardial infarction, followed by 12.5 mg orally three times a day; increase to 25 mg orally three times a day over the next several days, and then increase to target dose over the next several weeks as tolerated.

Target maintenance dose: 50 mg orally three times a day

Use: To improve survival following myocardial infarction in clinically stable patients with left ventricular dysfunction manifested as an ejection fraction of 40% or less and to reduce the incidence of overt heart failure and subsequent hospitalizations for congestive heart failure in these patients.

Usual Adult Dose for Diabetic Nephropathy:

25 mg orally three times a day

Comments: Other antihypertensives may be used in conjunction with this drug if additional blood pressure reduction is required.

Use: Treatment of diabetic nephropathy (proteinuria greater than 500 mg/day) in patients with type I insulin-dependent diabetes mellitus and retinopathy.

Usual Adult Dose for Hypertensive Emergency:

25 mg orally 2 to 3 times a day; continue diuretic therapy and stop other antihypertensives upon initiation of this drug; may increase dose every 24 hours or less until satisfactory blood pressure or maximum dose is reached.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking captopril?

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Do not take potassium supplements or use salt substitutes, unless your doctor has told you to.

Avoid becoming overheated or dehydrated during exercise, in hot weather, or by not drinking enough fluids. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

Avoid strenuous exercise if you are being treated for heart failure. Ask your doctor about your risk.

Captopril side effects

Get emergency medical help if you have signs of an allergic reaction to captopril: severe stomach pain, hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Captopril may cause serious side effects. Call your doctor at once if you have:

  • chest pain, fast, slow, or uneven heart rate;

  • a light-headed feeling, like you might pass out;

  • heart problems - swelling, rapid weight gain, feeling short of breath;

  • kidney problems - swelling, urinating less, feeling tired or short of breath;

  • signs of infection - fever, chills, sore throat, body aches, unusual tiredness, loss of appetite, bruising or bleeding;

  • high blood potassium - nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement;

  • low blood sodium - headache, confusion, problems with thinking or memory, weakness, feeling unsteady; or

  • low white blood cell counts - fever, mouth sores, skin sores, sore throat, cough.

Common captopril side effects may include:

  • cough;

  • low blood pressure;

  • flushing (sudden warmth, redness, or tingly feeling);

  • low blood cell counts;

  • decreased sense of taste; or

  • mild skin itching or rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect captopril?

Captopril can harm your kidneys, especially if you also use certain medicines for infections, cancer, or osteoporosis.

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with captopril, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use captopril only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.