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Drugs reference index «Captopril»



Pronunciation: (KAP-toe-prill)Class: ACE inhibitor

Trade Names:Capoten- Tablets 12.5 mg- Tablets 25 mg- Tablets 50 mg- Tablets 100 mg

APO-Capto (Canada)Gen-Captopril (Canada)PMS-Captopril (Canada)


Competitively inhibits angiotensin I-converting enzyme, preventing conversion of angiotensin I to angiotensin II, a potent vasoconstrictor that also stimulates aldosterone secretion. Results in decreased BP, potassium retention, and reduced sodium reabsorption.



T max is about 1 h. Food reduces absorption 30% to 40%.


About 25% to 30% protein bound.


More than 90% of a dose is eliminated in the urine; 40% to 50% is unchanged drug. The t ½ is less than 3 h.


60 to 90 min.

Special Populations

Renal Function Impairment

Excretion is reduced. Dosage reduction may be needed.

Indications and Usage

Treatment of hypertension, CHF, left ventricular dysfunction after MI, diabetic nephropathy.

Unlabeled Uses

Treatment of hypertensive crisis, neonatal and childhood hypertension, rheumatoid arthritis, diagnosis of anatomic renal artery stenosis and primary aldosteronism, treatment of hypertension related to scleroderma renal crisis and Takayasu disease, idiopathic edema, Bartter and Raynaud syndromes, asymptomatic left ventricular dysfunction after MI.


Hypersensitivity to ACE inhibitors.

Dosage and Administration

Diabetic NephropathyAdults

PO 25 mg 3 times daily.

Heart FailureAdults Initial dose

PO 6.25 to 12.5 mg 3 times daily; then titrate to usual daily dosage within next several days. Generally to be used in conjunction with a diuretic and digitalis.

HypertensionAdults Initial dose

PO 25 mg twice daily to 3 times daily; gradually increase every 1 to 2 wk if satisfactory effect is not achieved. Usual dose: 25 to 150 mg twice daily to 3 times daily. Usual dose does not exceed 50 mg 3 times daily. Max daily dose is 450 mg.

Left Ventricular Dysfunction after MIAdults

PO 6.25 mg 3 days after MI; then 12.5 mg 3 times daily and 25 mg 3 times daily for next several days.

Target dose

50 mg 3 times daily over next several wk.

General Advice

Give prescribed dose 1 h before or 2 h after meals.


Store tablets at controlled room temperature (59° to 89°F). Protect from moisture.

Drug Interactions


Reduces bioavailability of captopril.

Indomethacin, salicylates (eg, aspirin)

Hypotensive effects may be reduced, especially in low-renin or volume-dependent hypertensive patients.


Increased lithium levels and symptoms of lithium toxicity may occur.

Potassium preparations, potassium-sparing diuretics

May increase serum potassium levels.

Laboratory Test Interactions

False-positive urine acetone test may occur.

Adverse Reactions


Chest pain; palpitations; tachycardia; orthostatic hypotension.


Headache; sleep disturbances; paresthesias; dizziness; fatigue; malaise; ataxia; confusion; depression; nervousness.


Rash; pruritus; alopecia.


Rhinitis; cough.


Nausea; abdominal pain; vomiting; gastric irritation; aphthous ulcers; peptic ulcer; jaundice; cholestasis; diarrhea; dysgeusia; anorexia; constipation; dry mouth.


Oliguria; proteinuria.


Elevated liver enzymes and serum bilirubin.


Neutropenia; agranulocytosis; thrombocytopenia; pancytopenia.


Hyperkalemia; hyponatremia; elevated uric acid and blood glucose.


Chronic dry cough; dyspnea; eosinophilic pneumonitis.


Gynecomastia; myasthenia.




When used in pregnancy during the second and third trimesters, ACE inhibitors can cause injury and even death to the developing fetus. When pregnancy is detected, discontinue therapy as soon as possible.



Monitor and record BP and pulse. If symptomatic hypotension occurs, hold medication and notify health care provider.


Ensure that CBC with differential are evaluated prior to starting therapy, at 2 wk intervals for 3 mo, and periodically thereafter in patient with renal function impairment or CHF.

Heart failure patient

Assess heart failure patient for evidence of worsening failure (eg, daily weights, evaluation of peripheral edema, shortness of breath). Inform health care provider if rapid weight gain (eg, 2 pounds in 1 day or 5 pounds in 1 wk) is noted or if patient is experiencing worsening edema or other symptoms of heart failure (eg, worsening shortness of breath).


Category D (second and third trimester); Category C (first trimester). ACE inhibitors can cause injury or death to fetus if used during second or third trimester. When pregnancy is detected, discontinue ACE inhibitors as soon as possible.


Excreted in breast milk.


Safety and efficacy not established.

Renal Function

Because captopril is excreted primarily by the kidneys, patients with renal function impairment may require smaller or less frequent doses.


Use with extreme caution in patients with hereditary angioedema.

Hepatic failure

Rarely, ACE inhibitors have been associated with a syndrome that starts with cholestatic jaundice and progresses to fulminant hepatic necrosis and sometimes death.

Hypotension/first-dose effect

Significant decreases in BP may occur after first dose, especially in patients with severe salt or volume depletion or those with CHF.

Neutropenia and agranulocytosis

Risk appears greater with renal function impairment, CHF.


May occur, especially in patients with prior renal disease or those receiving high doses of drug (more than 150 mg/day); generally resolves within 6 mo.




Patient Information

  • Advise patient to take prescribed dose 1 h before or 2 h after meals because food can reduce absorption and benefits of medication.
  • Advise patient to try to take each dose at about the same time each day.
  • Inform hypertensive patient that drug controls, but does not cure, hypertension and to continue taking drug as prescribed even when BP is not elevated.
  • Caution patient not to change the dose or stop taking unless advised by health care provider.
  • Instruct patient to continue taking other medications for the condition as prescribed by health care provider.
  • Instruct patient in BP and pulse measurement skills.
  • Advise patient to monitor and record BP and pulse at home and to inform health care provider if abnormal measurements are noted. Also advise patient to take record of BP and pulse to each follow-up visit.
  • Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
  • Instruct patient to lie or sit down if experiencing dizziness or lightheadedness when standing.
  • Emphasize to hypertensive patient the importance of other modalities on BP control: weight control, regular exercise, smoking cessation, and moderate intake of alcohol and salt.
  • Emphasize to heart failure patient the importance of other modalities that can help control heart failure symptoms: weight control, progressive exercise program, smoking cessation, and moderate intake of alcohol and salt.
  • Advise heart failure patient to weigh daily, keep a record of daily weights, and notify health care provider if rapid weight gain (eg, 5 pounds in 1 wk) is noted or if edema or shortness of breath worsen.
  • Caution patient that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to excessive fall in BP resulting in lightheadedness or fainting.
  • Advise patient that medication may cause dizziness or lightheadedness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
  • Caution patient to avoid unnecessary exposure to UV light (sunlight, tanning booths) and to use sunscreen and wear protective clothing when exposed to UV light to avoid photosensitivity reaction.
  • Instruct patient to stop taking drug and immediately report any of the following symptoms to health care provider: sore throat, fever, irregular heartbeat, chest pains, fainting, signs or symptoms of angioedema (eg, swelling of the hands, feet, face, lips, eyelids, or tongue, hoarseness, difficulty swallowing or breathing).
  • Instruct patient to inform health care provider if a persistent cough or changes in taste develop while taking this medication.
  • Caution patient not to take any prescription or OTC medications, potassium-containing salt substitutes, potassium supplements, or dietary supplements unless advised by health care provider.

Copyright © 2009 Wolters Kluwer Health.

  • Captopril MedFacts Consumer Leaflet (Wolters Kluwer)
  • Captopril Detailed Consumer Information (PDR)
  • captopril Advanced Consumer (Micromedex) - Includes Dosage Information
  • Capoten Prescribing Information (FDA)
  • Capoten Consumer Overview

See Also...

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