Description: Captopril competitively inhibits the conversion of angiotensin I (ATI) to angiotensin II (ATII), thus resulting in reduced ATII levels and aldosterone secretion. It also increases plasma renin activity and bradykinin levels. Reduction of ATII leads to decreased Na and water retention. This promotes vasodilation and BP reduction.

Captopril, ACE inhibitor, lowers blood pressure by relaxing blood vessels so that blood can flow more easily. It is also used to treat heart failure, protect the kidneys from harm due to diabetes, and to improve survival after a heart attack.

How to use captopril

Take this medication by mouth on an empty stomach (at least 1 hour before meals) as directed by your doctor, usually two to three times a day.

The dosage is based on your medical condition and response to treatment.

Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same times each day. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick.

For the treatment of high blood pressure, it may take up to 2 weeks before you get the full benefit of this medication. For the treatment of heart failure, it may take weeks to months before you get the full benefit of this medication. Tell your doctor if your condition does not improve or if it worsens (such as your blood pressure readings remain high or increase).

This drug can cause serious (possibly fatal) harm to an unborn baby if used during pregnancy.

Tell your doctor or pharmacist promptly if any of these effects persist or worsen:

  • dizziness
  • lightheadedness
  • loss of taste
  • dry cough

Tell your doctor right away if any of these unlikely but serious side effects occur:

  • fainting
  • fast heartbeat
  • symptoms of a high potassium blood level (such as muscle weakness, slow/irregular heartbeat)
  • signs of infection (such as fever, chills, persistent sore throat)
  • change in the amount of urine
  • cloudy urine

This drug may rarely cause serious (possibly fatal) liver problems.

A very serious allergic reaction to this drug is rare.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.


  • Allergic reaction to this medication.
  • Patients with medical history of:
    • history of an allergic reaction that included swelling of the face/lips/tongue/throat (angioedema)
    • blood filtering procedures (such as LDL apheresis, dialysis)
    • collagen vascular disease (such as lupus, scleroderma)
    • high level of potassium in the blood
  • Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely.
  • Drink enough fluids to prevent dehydration.
  • Tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products) before having surgery.
  • Use of potassium supplements or salt substitutes that contain potassium.
  • Older adults may be more sensitive to dizziness and increases in potassium level.
  • This medication is not recommended for use during pregnancy.
  • Consult your doctor before breast-feeding.

Consult your doctor regarding the precautions mentioned above.



Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions.

Some products that may interact with this drug include:

  • Aliskiren
  • certain drugs that weaken the immune system/increase the risk of infection (such as everolimus, sirolimus)
  • lithium
  • drugs that may increase the level of potassium in the blood (such as ARBs including losartan/valsartan, birth control pills containing drospirenone)

Check the labels on all your medicines (such as cough-and-cold products, diet aids, or NSAIDs such as ibuprofen, naproxen) because they may contain ingredients that could increase your blood pressure or worsen your heart failure.

A very serious reaction may occur if you are getting injections for bee/wasp sting allergy (desensitization) and are also taking captopril.

This product may interfere with certain laboratory tests (including acetone urine test), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.


If overdose is suspected, contact a poison control center or emergency room immediately.

Notes: Do not share this medication with others.

Lifestyle changes such as stress reduction programs, exercise and dietary changes may increase the effectiveness of this medicine. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.

Laboratory and/or medical tests (such as kidney function, potassium levels) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Check your blood pressure regularly while taking this medication. Learn how to monitor your own blood pressure at home, and share the results with your doctor.

Missed Dose: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Storage: Store at room temperature away from light and moisture. It is normal for the drug to have a slight sulfur-like odor. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.



Available Brands

  • Bloc-Med [ AD-Drugstel ]
  • Capomed [ Medlink ]
  • Captobes [ Drugmaker’s Lab ]
  • Hartylox [ Integrated Pharma ]
  • Phil Pharmawealth/Panion & BF Captopril [ Panion & BF ]
  • RiteMED Captopril [ RiteMED ]
  • Tensoril [ Hizon ]

Also marketed as

  • Ace-Bloc [ Panion & BF ]
  • Boie Captopril [ Boie ]
  • Capotec [ Metrolink Pharma ]
  • Capoten [ Bristol-Myers Squibb ]
  • Captace [ E Denk ]
  • Captogen [ Pasteur Pharma ]
  • Captor [ Steinbach ]
  • Captril [ IAE ]
  • Cardiovaz [ Westward ]
  • Conamid [ Flamingo ]
  • Prelat [ Yung Shin ]
  • Prelat 25 [ YSP ]
  • Primace [ Pascual ]
  • Retensin [ Unison ]
  • Spec-Ace [ Pharmaspec ]
  • Vasostad [ Stada ]

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