What Is Captopril and How Does It Work?

Captopril is an angiotensin converting enzyme (ACE) inhibitor prescribed for treating high blood pressure, heart failure, and for preventing kidney failure due to high blood pressure and diabetes.

  • Captopril is available under the following different brand names: Capoten and Captoril.

What Are Dosage of Captopril?

Dosage of Captopril:

Adult and Pediatric Dosages


  • 12.5 mg
  • 25 mg
  • 50 mg
  • 100 mg

Geriatric Dosages

  • 12.5 mg
  • 25 mg

Dosage Considerations – Should be Given as Follows:

Acute Hypertension

Adult and geriatric:

  • 12.5-25 mg orally, may repeat as needed

Hypertension (alone or with Thiazide)

Adults and geriatric:

  • Initial: 25 mg orally every 8-12 hours, increase gradually based on response (may start lower in some patients)
  • Maintenance: 25-150 mg orally every 8-12 hours
  • 450 mg/day maximum

Pediatric (off-label)

  • Neonates: 0.05-0.1 mg/kg/dose every 8-24 hours, titrate dose up to 0.5 mg/kg/dose every 6-24 hours
  • Infants: 0.15-0.3 mg/kg/dose; titrate dose upward to maximum 6 mg/kg/day in 1-4 divided doses; 2.5-6 mg/kg/day usually required
  • Children: 0.3-0.5 mg/kg/dose; titrate to maximum 6 mg/kg/day divided every 6-12 hours
  • Older children: 6.25-12.5 mg/dose every 12-24 hours; titrate to no more than 6 mg/kg/day divided every 6-12 hours
  • Adolescents: 12.5-25 mg/dose every 8-12 hours; may increase by 25 mg/dose every 1-2 weeks to maximum 450 mg/day

Congestive Heart Failure (with Diuretics and Digitalis)

Adult and geriatric:

  • Target therapy: 50 mg every 8 hours
  • 450 mg/day maximum

Left Ventricular Dysfunction After Myocardial Infarction

Adult and geriatric:

  • 6.25 mg orally initially followed by 12.5 mg every 8 hours
  • Increase to 25 mg orally every 8 hours over next few days; THEN
  • Target dose: 50 mg orally every 8 hours

Diabetic Nephropathy

Adult and geriatric:

  • 25 mg orally every 8 hours

Dosing Considerations

  • Beneficial for many patients at risk for heart disease; reduces the risk of myocardial infarction, stroke, diabetic nephropathy, microalbuminuria, new-onset diabetes mellitus
  • Consider starting an ACE inhibitor in high-risk patients, even if no hypertension or congestive heart failure
  • May prolong survival in congestive heart failure, may preserve renal function in diabetes mellitus
  • May help to prevent migraine headache
  • Good choice in hyperlipidemia patients
  • Requires weeks for full effect; to start, use a low dose and titrate every 1-2 weeks


  • Take on an empty stomach

What Are Side Effects Associated with Using Captopril?

Side effects of captopril include:

  • hypersensitivity reactions
  • rash
  • distorted sense of taste
  • itching
  • chest pain
  • palpitations
  • protein in urine
  • fast heart rate
  • cardiac arrest
  • dizziness upon standing
  • problems with coordination
  • confusion
  • depression
  • sleepiness
  • skin swelling
  • sun sensitivity
  • low white blood cell count
  • acute renal failure in renal artery stenosis
  • kidney impairment
  • impotence
  • dry, persistent cough
  • abdominal pain
  • constipation
  • diarrhea
  • lightheadedness
  • drowsiness
  • fatigue
  • headache
  • sleep problems (insomnia)
  • loss of taste
  • loss of appetite
  • nausea
  • vomiting
  • dry mouth
  • sores inside your mouth or on your lips
  • numbness in the hands or feet
  • kidney failure
  • increased levels of potassium in the blood
  • high blood pressure
  • severe allergic reaction
  • enlarged breast in men (gynecomastia)
  • physical weakness
  • stroke
  • rhythm disturbances of the heart
  • fainting
  • chronic blistering of the skin
  • acute recurring skin condition (including Stevens-Johnson syndrome)
  • redness and peeling of the skin
  • pancreatitis
  • swollen tongue
  • shortness of breath
  • anemia
  • yellowing of eyes and skin (jaundice)
  • hepatitis
  • death of cells or tissue
  • intense itching
  • the low sodium level in the blood
  • muscle pain
  • muscle weakness of the eyes and face
  • difficulty swallowing
  • nervousness
  • sudden difficulty breathing
  • increased white blood cells in the lungs
  • stuffy nose
  • blurred vision
  • high blood sodium levels
  • elevations of BUN/serum creatinine
  • positive antinuclear antibody indicative of a compromised immune system
  • elevations of liver transaminases
  • elevations of alkaline phosphatase
  • elevations of serum bilirubin

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Captopril?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Captopril has no known severe interactions with other drugs.
  • Captopril has serious interactions with at least 45 different drugs.
  • Captopril has moderate interactions with at least 185 different drugs.
  • Captopril has minor interactions with at least 32 different drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.

What Are Warnings and Precautions for Captopril?


  • Discontinue as soon as possible when pregnancy detected; affects renin-angiotensin system causing oligohydramnios, which may result in fetal injury and/or death
  • This medication contains captopril. Do not take Capoten or Captopril if you are allergic to captopril or any ingredients contained in this drug
  • Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately


  • Hypersensitivity to ACE inhibitors
  • Anuria
  • History of ACEI-induced angioedema
  • Hereditary or idiopathic angioedema
  • Bilateral renal artery stenosis
  • Pregnancy (2nd and 3rd trimesters): Significant risk of fetal/neonatal morbidity and mortality
  • Do not coadminister with aliskiren in patients with diabetes mellitus or with renal impairment (GFR under 60 mL/min/1.73 m²)

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Captopril?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Captopril?"


  • Aortic stenosis/hypertrophic cardiomyopathy, hypotension, biliary cirrhosis or biliary obstruction, myelosuppression, electrolyte imbalance, hyperuricemia or gout, systemic lupus erythematosus (SLE), hepatic or renal impairment
  • Avoid concomitant use with lithium
  • Less effective in African-Americans
  • Excessive hypotension if concomitant diuretics or volume-depleted; start with 6.25 mg every 8 hours
  • Risk of hyperkalemia, especially with potassium-sparing diuretics
  • Dual blockade of the renin-angiotensin system with ARBs, ACE inhibitors, or aliskiren associated with increased risk for hypotension, hyperkalemia, and renal function changes (including acute renal failure) compared to monotherapy
  • Blood levels don't correlate with blood pressure response
  • Food decreases absorption
  • ACE inhibition also causes increased bradykinin levels which putatively mediates skin swelling
  • Coadministration with mTOR inhibitors (temsirolimus, everolimus, sirolimus) may increase the risk for skin swelling
  • The intestinal skin swelling, that presented with abdominal pain, reported in patients treated with ACE inhibitors
  • Neutropenia (under 1000/mm³ with myeloid hypoplasia reported with captopril; risk is dependent on the clinical status of the patient
  • Causes false-positive urine acetone

Pregnancy and Lactation

  • Use captopril with caution in the first trimester of pregnancy if benefits outweigh risks
  • Animal studies show risk and human studies are not available or neither animal nor human studies were done
  • During the 2nd and 3rd trimesters of pregnancy, use captopril during pregnancy only in LIFE-THREATENING emergencies when no safer drug is available
  • There is positive evidence of human fetal risk
  • Discontinue captopril as soon as pregnancy is detected
  • During the second and third trimesters of pregnancy, drugs that act directly on the renin-angiotensin have been associated with a fatal injury that includes hypotension, neonatal skull hypoplasia, anuria, reversible or irreversible renal failure, and death
  • Captopril enters breast milk and is not recommended to use while breastfeeding (the American Association of Pediatrics states it is compatible with breastfeeding)
Medscape. Captopril.
RxList. Capoten Monograph.

Health Solutions From Our Sponsors