Generic
Captopril
11 brands available in the market
At a glance
Captopril is an ACE inhibitor used in the treatment of hypertension, heart failure, and post-myocardial infarction. It dilates blood vessels and reduces cardiac workload to control blood pressure.
Description
Captopril is an angiotensin-converting enzyme (ACE) inhibitor used for hypertension, heart failure, and post-MI treatment. It competitively inhibits the conversion of angiotensin I to angiotensin II, reducing angiotensin II levels and aldosterone secretion, and increasing plasma renin activity and bradykinin levels. Reduced angiotensin II leads to decreased sodium and water retention, promoting vasodilation and blood pressure reduction.
Captopril is indicated for mild-to-moderate hypertension (as an adjunct to thiazide therapy), severe hypertension (when standard therapy has failed), and congestive heart failure (with diuretics and digitalis).
Indications
- Mild-to-moderate hypertension (adjunct to thiazide therapy)
- Severe hypertension (when standard therapy has failed)
- Congestive heart failure (with diuretics and digitalis)
- Post-myocardial infarction treatment
Therapeutic class
Angiotensin-converting enzyme (ACE) inhibitors
Pharmacological class
ACE Inhibitor
Pharmacology
Captopril competitively inhibits angiotensin-converting enzyme (ACE), reducing the conversion of angiotensin I to angiotensin II, decreasing angiotensin II levels and aldosterone secretion, and increasing plasma renin activity and bradykinin levels. Reduced angiotensin II leads to decreased sodium and water retention, promoting vasodilation and blood pressure reduction.
Mechanism of action
Captopril inhibits ACE, preventing the conversion of angiotensin I to angiotensin II, leading to vasodilation, reduced blood pressure, and decreased cardiac workload.
Dosage
Hypertension (Mild-moderate): Initial 12.5 mg twice daily; Maintenance 25 mg twice daily (max 50 mg twice daily).
Severe hypertension: Initial 12.5 mg twice daily; max 50 mg three times daily.
Heart failure: Initial 6.25-12.5 mg 2-3 times daily; Maintenance 25 mg three times daily; max 150 mg/day.
Post-MI: Start 3 days after MI; Initial 6.25 mg/day; may increase to 150 mg/day in divided doses.
Diabetic nephropathy: 25 mg three times daily.
Elderly: Initial 6.25 mg twice daily.
Children (Neonates and infants): 0.15 mg/kg (max 6 mg/kg) in 2-3 divided doses.
Children and adolescents: 0.3 mg/kg (max 6 mg/kg) in 2-3 divided doses.
Heart failure (Children): Initial 0.25 mg/kg/day; up to 2.5-3.5 mg/kg/day in 3 divided doses.
Renal impairment (CrCl):
CrCl <10 mL/min: Initial 6.25 mg/day; max 37.5 mg/day.
CrCl 10-20: Initial 12.5 mg/day; max 75 mg/day.
CrCl 21-40: Initial 25 mg/day; max 100 mg/day.
Note: Take 1 hour before meals for maximum absorption.
Administration
Take 1 hour before meals on an empty stomach for maximum absorption. Swallow tablets whole; do not chew or crush. Take at a fixed time each day.
Missed dose
If you miss a dose, skip it and continue with your normal schedule. Do not double the dose.
Side effects
Hypotension, cough, hyperkalemia, fatigue, weakness, dizziness, neutropenia, anemia, proteinuria, tachycardia, pruritic rash, gastric irritation, abdominal pain.
Precautions & warnings
- May cause dizziness for the first few days; rise slowly from sitting or lying position.
- Inform your doctor about any persistent cough or throat irritation (ACE inhibitor-induced cough).
- Avoid potassium supplements and potassium-rich foods (banana, broccoli) due to hyperkalemia risk.
- Do not use during pregnancy (Category D).
- Avoid in aortic stenosis or outflow tract obstruction.
- Caution in renal impairment (risk of neutropenia and proteinuria).
- Caution in hepatic impairment; inform your doctor if jaundice symptoms develop.
Contraindications
- Previous hypersensitivity to captopril
- Pregnancy
- Bilateral renal artery stenosis
- Hereditary angioedema
- Renal impairment
Drug interactions
- NSAIDs: Reduce hypotensive action and increase risk of nephrotoxicity.
- Potassium supplements, potassium-sparing diuretics, heparin: Additive hyperkalemic effect.
- Procainamide, allopurinol, cytostatic or immunosuppressants: Increased risk of leukopenia.
- Lithium: Increased risk of lithium toxicity.
- Gold (sodium aurothiomalate): Increased risk of nitritoid reactions.
- Aliskiren (in diabetic patients): Increased risk of hypotension, hyperkalemia, and renal function changes (potentially fatal).
Food interactions
Alcohol consumption does not cause harmful effects. However, general caution is advised.
Use in pregnancy
Unsafe during pregnancy (Category D). Definite evidence of risk to the developing baby. May be used in life-threatening situations if benefits outweigh risks. Discontinue as soon as pregnancy is detected.
Pregnancy Category: D — always consult a doctor before taking during pregnancy.
Use in lactation
Safe during breastfeeding (if prescribed). Human studies suggest the drug does not pass into breast milk in significant amounts and is not harmful to the baby.
Pediatric use
Safety and effectiveness in pediatric patients have not been established. Pediatric doses: 0.15-0.3 mg/kg (max 6 mg/kg) in 2-3 divided doses.
Geriatric use
Elderly: Initial dose 6.25 mg twice daily.
Renal / hepatic impairment
Hepatic impairment: Caution required; dose adjustment may be needed. Inform your doctor if jaundice symptoms develop.
Overdose effects
Overdose may cause severe hypotension. Treatment: Blood pressure correction (IV fluids, vasopressors), gastric lavage. Consult your doctor immediately if overdose is suspected.
Storage conditions
Store below 30°C, away from light and moisture. Keep out of reach of children.
Chemical structure
Captopril