Actions and Spectrum 

The primary action of captopril is to lower blood pressure by relaxing the blood vessels and reducing the workload of the heart. It does this by inhibiting the activity of ACE, an enzyme that converts angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor, meaning it narrows the blood vessels and increases blood pressure.

By blocking the production of angiotensin II, captopril can help to lower blood pressure and reduce the risk of cardiovascular events such as heart attack and stroke. captopril is also sometimes used to treat kidney problems caused by diabetes and to improve survival after a heart attack. It may be used in combination with other medications to achieve these effects. 

In terms of its spectrum of activity, captopril is effective at lowering blood pressure in a wide range of patients, including those with hypertension, congestive heart failure, and kidney problems. It is generally well-tolerated, although some people may experience side effects such as dizziness, fatigue, and a dry cough. 

 

DRUG INTERACTION

Contraindicated  

Serious Use Alternative  

Monitor Closely  

Minor  

Frequency Defined  

>10%  

Hyperkalemia (1-11%)  

1-10%  

Skin rash (4-7%)  

Hypotension (1-2.5%)  

Dysgeusia (2-4%)  

Pruritus (2%)  

Chest pain (1%)  

Hypersensitivity rxns (4-7%)  

Cough (0.5-2%)  

Palpitations (1%)  

Tachycardia (1%)  

Proteinuria (1%)  

Frequency Not Defined  

Orthostatic hypotension  

Cardiac arrest  

Ataxia  

Depression  

Confusion  

Somnolence  

Photosensitivity  

Angioedema  

 

 

Black Box Warning 

The black box warning for captopril, a medication used to treat high blood pressure and heart failure, states that the drug can cause serious or life-threatening allergic reactions, including angioedema (swelling of the face, lips, tongue, or throat).

The warning also advises that captopril should not be used in patients with a history of angioedema or hypersensitivity to the drug. In addition, the black box warning for captopril notes that the drug can cause fetal harm when used during pregnancy and advises that it should be avoided in pregnant women or women who may become pregnant. 

 

Contraindications: 

• Hypersensitivity to captopril or any other component of the medication 
• Pregnancy (can cause fetal harm or death) 
• Breastfeeding (may be excreted in breast milk and can harm a nursing infant) 

Cautions: 

• Renal impairment (dose adjustment may be needed) 
• Hepatic impairment (dose adjustment may be needed) 
• History of angioedema (risk of recurrent angioedema) 
• Dehydration (risk of hypotension) 
• Elderly patients (risk of hypotension and electrolyte abnormalities) 
• Use with other medications that lower blood pressure (increased risk of hypotension) 
• Use with medications that inhibit the renin-angiotensin-aldosterone system (increased risk of hypotension and electrolyte abnormalities) 

 

Pregnancy warnings:     

US FDA pregnancy category: C; D in 2nd & 3rd trimesters 

Lactation:   

Excreted into human milk is known  

Pregnancy Categories:         

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.    

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.     

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.     

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.     

Category N: There is no data available for the drug under this category 

 

 

Pharmacology:  

captopril is a medication that belongs to a class of drugs known as angiotensin converting enzyme inhibitors (ACE inhibitors). It is used to treat hypertension (high blood pressure) and heart failure, as well as to prevent kidney damage in individuals with diabetes or hypertension. 

Pharmacodynamics:  

captopril is an angiotensin-converting enzyme (ACE) inhibitor, which means it works by inhibiting the enzyme responsible for converting angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor that increases blood pressure and constricts blood vessels. By inhibiting the conversion of angiotensin, I to angiotensin II, captopril causes blood vessels to relax and blood pressure to decrease. 

captopril also increases the production of bradykinin, which is a chemical that causes blood vessels to dilate and reduces inflammation. captopril is primarily used to treat hypertension, but it can also be used to treat heart failure, kidney disease, and myocardial infarction.  

The pharmacodynamics of captopril may be affected by certain factors such as age, weight, kidney function, and other medications being taken. 

Pharmacokinetics:  

Absorption   

It is absorbed rapidly after oral administration   

Distribution   

Reaches peak plasma concentrations within 1-2 hours. The bioavailability of captopril is low, around 10-20%, due to a high degree of first-pass metabolism in the liver.  

Metabolism   

captopril is metabolized in the liver by the enzyme dipeptidyl peptidase IV (DPP-IV) to its active form, enalaprilat. Enalaprilat is highly protein bound, primarily to albumin.  

Elimination and excretion  

captopril is eliminated from the body primarily through the kidneys via glomerular filtration and tubular secretion. The half-life of captopril is 1-2 hours, while the half-life of enalaprilat is 4-6 hours.  

 

 

Administration:  

Oral administration:  

captopril is an oral medication that is typically taken 1-3 times a day. It should be taken with food to help prevent stomach irritation. The dosage will depend on the patient’s blood pressure, kidney function, and other factors. It is important to follow the prescribed dosage and schedule as directed by a healthcare provider.   

Missed dose:  

If a dose is missed, it should be taken as soon as possible. However, if it is almost time for the next dose, the missed dose should be skipped, and the regular schedule should be resumed. It is important not to take extra doses of captopril or to change the dosage without consulting a healthcare provider.   

Storage:  

captopril should be stored at room temperature and kept out of reach of children.  

 

 

Patient information leaflet 

Generic Name: captopril  

Why do we use captopril? 

captopril is used to treat high blood pressure (hypertension) and heart failure. It belongs to a class of medications called angiotensin-converting enzyme (ACE) inhibitors, which work by blocking the production of a hormone called angiotensin II. Angiotensin II constricts blood vessels and increases blood pressure, so by blocking its production, captopril helps to relax blood vessels and lower blood pressure. captopril may also be used to prevent kidney damage in people with diabetes and to treat kidney disorders caused by a protein called lupus nephritis.