Captopril tablets for hypertension, heart failure, and diabetic nephropathy

Captopril tablets are oral medications containing the active ingredient captopril, an angiotensin-converting enzyme (ACE) inhibitor. They are used to manage high blood pressure (hypertension), congestive heart failure, improve survival after heart attack in patients with left ventricular dysfunction, and treat diabetic nephropathy in patients with type I diabetes. Captopril works by blocking the formation of angiotensin II, a substance that constricts blood vessels, thereby lowering blood pressure and reducing strain on the heart and kidneys.

• Hypertension: Treatment of high blood pressure in adult patients, including use as initial therapy in patients with normal kidney function.
• Congestive heart failure: Used usually alongside diuretics and digitalis to improve heart function.
• Post-myocardial infarction: To improve survival and reduce the risk of heart failure in clinically stable patients with left ventricular ejection fraction ≤ 40%.
• Diabetic nephropathy: Treatment of proteinuria (>500 mg/day) and slowing progression of renal disease in patients with type I insulin-dependent diabetes mellitus and retinopathy.

Captopril

Captopril blocks angiotensin-converting enzyme (ACE), which normally converts angiotensin I to angiotensin II, a potent blood vessel constrictor. By inhibiting ACE, captopril lowers angiotensin II levels, leading to dilation of blood vessels, decreased blood pressure, and reduced workload on the heart. It also lowers aldosterone secretion, encouraging sodium and fluid loss, which helps reduce blood volume. Additionally, captopril may increase levels of bradykinin, a peptide that dilates blood vessels, contributing to its blood pressure-lowering effects.

Dosing varies by indication and patient condition. Tablets are available in 12.5 mg, 25 mg, 50 mg, and 100 mg strengths. For hypertension, dosing often starts low and may be increased over weeks to achieve blood pressure control. Captopril should be taken one hour before meals to ensure optimal absorption since food reduces its absorption by 30-40%. In heart failure, typical dosing starts at 6.25 mg or 12.5 mg three times daily, titrated to a target maintenance dose of 50 mg three times daily. For diabetic nephropathy, a common dose is 25 mg three times daily. Dose adjustments are necessary in patients with renal impairment. Abrupt withdrawal is not associated with rebound hypertension but should still be managed by a healthcare provider.

• Hypersensitivity to captopril or any other ACE inhibitor, especially history of angioedema related to ACE inhibitors.
• Use with aliskiren in patients with diabetes.
• Use with neprilysin inhibitors (e.g., sacubitril) or within 36 hours of switching to or from sacubitril/valsartan.

• Fetal toxicity: Captopril can cause injury and death to the developing fetus. Discontinue as soon as pregnancy is detected.
• Angioedema: May cause swelling of face, lips, tongue, glottis, or larynx; can be life-threatening if airway obstruction occurs. Emergency treatment with epinephrine is required.
• Neutropenia/agranulocytosis: Risk of severe reduction in neutrophils, especially in patients with impaired renal function or collagen vascular disease; monitor blood counts carefully.
• Hypotension: May occur, especially in volume-depleted patients.
• Do not co-administer with aliskiren in diabetic patients or with neprilysin inhibitors (e.g., sacubitril). Avoid use within 36 hours of switching to or from neprilysin inhibitors.

• Common: Hypotension, dizziness, cough, rash.
• Serious: Angioedema, neutropenia/agranulocytosis, elevated potassium, renal impairment, anaphylactoid reactions during dialysis or LDL apheresis.

• Combination with neprilysin inhibitors (e.g., sacubitril) is contraindicated due to risk of angioedema.
• Co-administration with aliskiren is contraindicated in patients with diabetes.
• Use with mTOR inhibitors (temsirolimus, sirolimus, everolimus) or neprilysin inhibitors may increase angioedema risk.
• May interact with diuretics, beta blockers, aspirin, nitrates, calcium antagonists, and other antihypertensives.

Pregnancy: Captopril can cause fetal harm; discontinue immediately when pregnancy is detected.

Lactation: Information not provided in the supplied evidence.