Capoten (captopril) is an angiotensin-converting enzyme (ACE) inhibitor indicated for the management of hypertension, heart failure, and diabetic nephropathy. As a first-generation ACE inhibitor, it remains a clinically relevant therapeutic option due to its established efficacy profile and rapid onset of action. This medication works by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, thereby reducing peripheral vascular resistance and decreasing blood pressure. Its therapeutic utility extends to post-myocardial infarction care and certain renal conditions, making it a versatile agent in cardiovascular and renal medicine.

Features

• Active ingredient: Captopril 12.5 mg, 25 mg, 50 mg, 100 mg tablets
• Pharmacologic class: Angiotensin-converting enzyme (ACE) inhibitor
• Rapid onset of action with peak plasma concentrations achieved within 60-90 minutes
• Bioavailability of approximately 60-75% when administered orally
• Elimination half-life of approximately 2 hours in patients with normal renal function
• Excretion primarily renal (95%) with some fecal elimination
• White to off-white, square, biconvex tablets with distinctive cross-scoring

Benefits

• Effectively lowers blood pressure by reducing peripheral vascular resistance through ACE inhibition
• Demonstrates cardioprotective effects in heart failure patients by decreasing afterload and improving cardiac output
• Shows renoprotective properties in diabetic nephropathy by reducing proteinuria and slowing disease progression
• Provides rapid therapeutic effect suitable for hypertensive urgency management
• Offers flexible dosing regimen accommodative to various patient populations and clinical scenarios
• May improve endothelial function and reduce left ventricular hypertrophy over long-term use

Common use

Capoten is primarily prescribed for the treatment of hypertension, either as monotherapy or in combination with other antihypertensive agents. It is indicated for management of heart failure, particularly in patients who have not responded adequately to diuretics and digitalis. The medication is also used in the treatment of diabetic nephropathy (proteinuria >500 mg/day) in insulin-dependent diabetic patients. Additionally, Capoten is employed following myocardial infarction in clinically stable patients with left ventricular dysfunction (ejection fraction ≤40%) to improve survival and reduce the incidence of overt heart failure. Off-label uses include management of scleroderma renal crisis and certain forms of secondary hypertension.

Dosage and direction

Hypertension: Initial dose: 25 mg twice daily; may increase to 50 mg twice daily after 1-2 weeks. Maintenance: 25-150 mg twice daily. Maximum dose: 450 mg/day.

Heart Failure: Initial dose: 6.25-12.5 mg three times daily under close medical supervision. Target maintenance: 50-100 mg three times daily.

Diabetic Nephropathy: 25 mg three times daily.

Post-Myocardial Infarction: May be initiated 3-16 days after infarction at 6.25 mg dose, then 12.5 mg three times daily, increasing to 50 mg three times daily.

Administration should occur one hour before meals for optimal absorption. Dosage adjustments are necessary in renal impairment: For creatinine clearance 10-50 mL/min, administer 75% of normal dose; for clearance below 10 mL/min, administer 50% of normal dose. Elderly patients may require lower initial doses due to potentially reduced renal function.

Precautions

Monitor blood pressure closely during initial therapy and following dosage adjustments. Assess renal function and serum potassium before initiation and periodically during treatment. Use with caution in patients with renal artery stenosis, as acute renal failure may occur. Avoid use in patients with collagen vascular diseases due to increased risk of neutropenia/agranulocytosis. Exercise caution in patients undergoing major surgery or during anesthesia due to potential hypotension. Patients should maintain adequate hydration but avoid excessive diuresis. Pregnancy Category D (second and third trimesters) - may cause injury and death to the developing fetus. Not recommended during breastfeeding.

Contraindications

History of angioedema related to previous ACE inhibitor treatment. Patients with hereditary or idiopathic angioedema. Concomitant use with aliskiren in patients with diabetes. Hypersensitivity to captopril or any component of the formulation. Bilateral renal artery stenosis or stenosis in a solitary kidney. Concomitant use with sacubitril/valsartan - must discontinue Capoten at least 36 hours before starting sacubitril/valsartan.

Possible side effect

Common (>10%): Cough (persistent, dry), taste disturbance, rash, hypotension (especially after initial doses)

Less common (1-10%): Hyperkalemia, dizziness, fatigue, nausea, headache, proteinuria

Rare (<1%): Angioedema, neutropenia/agranulocytosis, renal impairment, hepatitis, pancreatitis, photosensitivity

Cardiovascular: Palpitations, chest pain, tachycardia Dermatological: Pruritus, alopecia, pemphigoid-like reactions Hematological: Anemia, thrombocytopenia Metabolic: Hyponatremia, hypoglycemia

Drug interaction

Potassium supplements/potassium-sparing diuretics: Increased risk of hyperkalemia Lithium: Increased lithium levels and toxicity NSAIDs: May diminish antihypertensive effect and increase risk of renal impairment Diuretics: Potentiated hypotensive effect, especially after first dose Gold injections: Nitritoid reactions (flushing, nausea, hypotension) Allopurinol: Increased risk of hypersensitivity reactions Oral hypoglycemics/insulin: Enhanced hypoglycemic effect Sympathomimetics: May reduce antihypertensive effect

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. Do not double the dose to make up for a missed administration. If multiple doses are missed, contact healthcare provider for guidance on resuming therapy. Maintain regular dosing schedule to ensure consistent blood pressure control.

Overdose

Symptoms primarily include hypotension, which may be severe. Bradycardia, electrolyte disturbances, and renal failure may occur. Management involves supportive care with volume expansion with normal saline. Hemodialysis may be effective in removing captopril. Monitor vital signs, electrolyte levels, and renal function closely. Angiotensin II infusion may be considered for severe hypotension unresponsive to conventional therapy. Symptomatic treatment should be provided for specific manifestations.

Storage

Store at controlled room temperature (20-25°C or 68-77°F). Protect from moisture and light. Keep container tightly closed. Do not remove desiccant from bottle. Keep out of reach of children. Do not use after expiration date printed on packaging. Do not transfer tablets to other containers unless specifically designed for medication storage.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting or changing any medication regimen. Individual patient responses may vary. Proper diagnosis and therapeutic monitoring are essential for safe and effective use. The prescribing physician should be familiar with complete prescribing information before administration.

Reviews

Clinical studies demonstrate Capoten’s efficacy in reducing blood pressure by 10-15% in hypertensive patients. Meta-analyses of ACE inhibitors show approximately 20% reduction in stroke risk and 15% reduction in coronary heart disease events. In heart failure trials, captopril reduced mortality by 27% compared to placebo. Diabetic nephropathy studies show 50% reduction in risk of doubling serum creatinine and significant reduction in proteinuria. Patient satisfaction surveys indicate good tolerability profile, though cough remains a frequently reported side effect affecting approximately 5-20% of users. Long-term follow-up studies confirm sustained efficacy and safety profile over decades of clinical use.