Capoten (captopril) is an angiotensin-converting enzyme (ACE) inhibitor indicated for the treatment of hypertension, heart failure, and diabetic nephropathy. It works by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in decreased systemic vascular resistance and blood pressure. This medication represents a cornerstone in cardiovascular pharmacotherapy, offering a well-established mechanism of action supported by decades of clinical evidence. Proper patient selection and adherence to dosing protocols are essential for optimizing therapeutic outcomes and minimizing potential adverse effects.

Features

• Active ingredient: Captopril
• Drug class: Angiotensin-converting enzyme (ACE) inhibitor
• Available formulations: 12.5 mg, 25 mg, 50 mg, and 100 mg tablets
• Administration route: Oral
• Onset of action: 15-60 minutes after administration
• Duration of effect: Dose-dependent, typically 6-12 hours
• Bioavailability: Approximately 60-75%
• Protein binding: 25-30%
• Metabolism: Hepatic (minimal)
• Elimination half-life: Approximately 2 hours
• Excretion: Primarily renal (95%)

Benefits

• Effectively lowers blood pressure through vasodilation and reduced aldosterone secretion
• Improves survival rates in patients with congestive heart failure
• Slows progression of diabetic nephropathy in type 1 diabetes patients
• Reduces afterload on the heart, improving cardiac output
• May decrease proteinuria in diabetic patients
• Provides flexible dosing options for individualized treatment regimens

Common use

Capoten is primarily prescribed for the management of hypertension, either as monotherapy or in combination with other antihypertensive agents. It is also indicated for the treatment of heart failure, particularly in patients who have not responded adequately to diuretics and digitalis. Additionally, Capoten is used in the management of diabetic nephropathy in patients with type 1 diabetes mellitus and retinopathy, where it has been shown to reduce the rate of progression of renal disease. Off-label uses include the treatment of Raynaud’s phenomenon and certain types of scleroderma renal crisis.

Dosage and direction

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

Heart Failure: Initial dose: 6.25-12.5 mg three times daily; increase gradually to 50-100 mg three times daily as tolerated.

Diabetic Nephropathy: 25 mg three times daily.

Administration should occur one hour before meals for optimal absorption. Dosage adjustments are necessary in patients with renal impairment. Elderly patients may require lower initial doses. Regular monitoring of blood pressure, renal function, and serum potassium is essential during therapy.

Precautions

Monitor blood pressure closely during initial therapy and after dosage adjustments. Assess renal function before initiation and periodically during treatment. Regular serum potassium monitoring is mandatory, especially in patients receiving potassium supplements or potassium-sparing diuretics. Use with caution in patients with collagen vascular diseases or those receiving immunosuppressive therapy due to increased risk of neutropenia/agranulocytosis. Avoid use in pregnancy due to potential fetal harm. Patients should be advised about the possibility of angioedema and instructed to seek immediate medical attention if it occurs.

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. Pregnancy (second and third trimesters).

Possible side effect

Common (>10%): Cough (persistent, dry), dizziness, taste disturbance, rash Less common (1-10%): Hypotension, hyperkalemia, headache, fatigue, nausea Rare (<1%): Angioedema, neutropenia/agranulocytosis, proteinuria, hepatic dysfunction, pancreatitis Very rare: Stevens-Johnson syndrome, toxic epidermal necrolysis, photosensitivity

Drug interaction

Potassium supplements/potassium-sparing diuretics: Increased risk of hyperkalemia Lithium: Increased lithium levels and toxicity NSAIDs: Reduced antihypertensive effect and increased risk of renal impairment Diuretics: Potentiated hypotensive effect Allopurinol: Increased risk of hypersensitivity reactions Gold injections: Nitritoid reactions Antidiabetic agents: Enhanced hypoglycemic 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 dose. Maintain regular dosing schedule to ensure consistent blood pressure control. Patients should be educated about the importance of adherence to prescribed regimen.

Overdose

Symptoms include profound hypotension, bradycardia, circulatory shock, electrolyte disturbances, and renal failure. Management involves immediate medical attention. Treatment is supportive and includes volume expansion with normal saline, vasopressor therapy if necessary, and monitoring of vital signs and electrolyte status. Hemodialysis may be effective in removing captopril from the circulation.

Storage

Store at controlled room temperature (20-25°C or 68-77°F). Protect from moisture and light. Keep in original container with tight closure. Do not use if tablets show signs of discoloration or deterioration. Keep out of reach of children and pets. Do not use after expiration date printed on packaging.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Capoten is a prescription medication that should only be used under the supervision of a qualified healthcare professional. Dosage and treatment duration should be determined by a physician based on individual patient characteristics and medical history. Patients should not discontinue or adjust therapy without consulting their healthcare provider.

Reviews

Clinical studies demonstrate Capoten’s efficacy in hypertension management with response rates of 60-70% in mild to moderate hypertension. In heart failure trials, captopril has shown significant mortality reduction compared to placebo. The SAVE trial demonstrated 19% reduction in all-cause mortality in post-MI patients with left ventricular dysfunction. Diabetic nephropathy studies show 50% reduction in risk of doubling serum creatinine in type 1 diabetics. Patient satisfaction surveys indicate good tolerability, though cough remains a frequent reason for discontinuation (occurring in 5-20% of patients). Long-term follow-up studies confirm sustained efficacy and safety profile over decades of clinical use.