CAPOTEN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CAPOTEN (CAPOTEN).
Competitive inhibitor of angiotensin-converting enzyme (ACE), preventing conversion of angiotensin I to angiotensin II, leading to decreased vasoconstriction, reduced aldosterone secretion, and increased plasma renin activity.
| Metabolism | Primarily hepatic metabolism, with 50% of the dose metabolized in the liver. Metabolites are excreted in urine (60%) and feces (40%). |
| Excretion | Primarily renal (approximately 60-75% as unchanged drug and metabolites) and biliary/fecal (approximately 20%). |
| Half-life | Terminal elimination half-life is approximately 1.9 hours in healthy subjects, but prolonged in heart failure (up to 3-4 hours) and renal impairment (up to 5-10 hours). |
| Protein binding | Approximately 25-30%, primarily to albumin. |
| Volume of Distribution | 0.7 L/kg; relatively low, indicating limited extravascular distribution. |
| Bioavailability | Oral: Approximately 75% (range 60-75%); reduced by food (by 30-40%). |
| Onset of Action | Oral: 15-30 minutes for reduction in blood pressure. |
| Duration of Action | Oral: 6-12 hours for blood pressure reduction, dose-dependent. |
| Molecular Weight | 217.29 |
| Action Class | Cephalosporins: 3 generation |
| Brand Substitutes | Gudcef 200 Tablet, Zipod 200mg Tablet, Brotacef 200mg Tablet, Oxipod 200mg Tablet, Monocef-O 200 Tablet, Proxit 100mg Tablet, Kefodime 100mg Tablet, Poxivio 100mg Tablet, Cefdron 100mg Tablet, Foloup 100mg Tablet |
50 mg orally three times daily initially; maintenance 50-100 mg three times daily; maximum 450 mg/day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-60 mL/min: 50% of usual dose. GFR 10-30 mL/min: 25% of usual dose. GFR <10 mL/min: 12.5 mg once daily. |
| Liver impairment | No specific Child-Pugh based guidelines available; use with caution and consider dose reduction in severe hepatic impairment. |
| Pediatric use | 0.3-2 mg/kg/day in 3 divided doses; maximum 6 mg/kg/day. Monitor blood pressure closely. |
| Geriatric use | Initiate at 25 mg twice daily; titrate slowly; monitor renal function and avoid hypovolemia. |
| 1st trimester | Avoid in first trimester; associated with increased risk of congenital malformations (renal, cardiac, CNS) due to interference with fetal renin-angiotensin system. |
| 2nd trimester | Contraindicated in second and third trimesters; causes fetal renal dysfunction, oligohydramnios, skull ossification defects, and neonatal renal failure. |
| 3rd trimester | Contraindicated in third trimester; increases risk of fetal and neonatal morbidity and death. |
Clinical note
Comprehensive clinical and safety monograph for CAPOTEN (CAPOTEN).
| Placental transfer | Captopril crosses the placenta; detectable in fetal cord blood and amniotic fluid. Evidence of transfer in animal studies and human case reports. |
| Breastfeeding | Captopril is excreted into breast milk in low concentrations (approximately 0.019% of weight-adjusted maternal dose). No adverse effects reported in nursing infants; however, theoretical risk of hypotension and renal impairment. Use with caution in preterm or renally impaired infants. |
■ FDA Black Box Warning
Fetal toxicity: Drugs acting directly on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as pregnancy is detected.
| Serious Effects |
History of angioedema related to previous ACE inhibitor therapyConcomitant use with aliskiren in patients with diabetes mellitusHypersensitivity to captopril or any ACE inhibitorBilateral renal artery stenosisPregnancy (especially second and third trimesters)
| Precautions | Angioedema: Risk of head and neck angioedema; increased risk in black patients., Hypotension: Excessive hypotension may occur, especially in volume-depleted patients., Neutropenia/agranulocytosis: Risk increased in patients with renal impairment or collagen vascular disease., Renal impairment: Monitor renal function; may cause reversible renal dysfunction., Hyperkalemia: Risk increased with renal impairment, diabetes, or concurrent potassium-sparing diuretics. |
| Food/Dietary | Avoid potassium-rich foods in large amounts (e.g., bananas, oranges, potatoes, spinach, tomatoes, avocados) unless specifically directed by a physician. Do not use salt substitutes containing potassium chloride. Grapefruit juice has not been shown to interact significantly with captopril. Alcohol may increase hypotensive effects and cause dizziness; limit intake. Food decreases absorption of captopril; take on an empty stomach (1 hour before or 2 hours after meals). |
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| Lactation Rating | L3 - Limited data suggests compatibility; use with caution. |
| Teratogenic Risk | First trimester: Risk of congenital malformations (renal, CNS) based on ACE inhibitor class effect. Second and third trimesters: Oligohydramnios, fetal renal dysfunction, skull ossification defects, hypotension, anuria, and neonatal death. Contraindicated in pregnancy. |
| Fetal Monitoring | Monitor maternal blood pressure, renal function, serum potassium, and fetal ultrasound for oligohydramnios and skeletal anomalies. Perform neonatal assessment for hypotension and renal function after delivery. |
| Fertility Effects | No direct evidence of impaired fertility in humans; animal studies show no significant reproductive toxicity at therapeutic doses. |
| Clinical Pearls | First-dose hypotension risk, especially in volume-depleted patients; titrate dose slowly. Monitor renal function and potassium levels due to risk of hyperkalemia and acute kidney injury. Use with caution in bilateral renal artery stenosis. ACE inhibitor-induced angioedema can occur. Discontinue if pregnancy occurs. Cough is a common side effect, may require switching to ARB. Avoid potassium supplements and potassium-sparing diuretics. Adjust dose in renal impairment based on creatinine clearance. Check for rash and taste disturbances, which are reversible. Use with caution in patients on immunosuppressants or those with autoimmune diseases due to risk of neutropenia/agranulocytosis. |
| Patient Advice | Take exactly as prescribed, usually one to two times daily. Do not stop without consulting your doctor. · This medication can cause dizziness, especially after the first dose. Get up slowly from sitting or lying down to prevent falls. · Report any swelling of the face, lips, tongue, or difficulty breathing immediately — this could be a sign of a serious allergic reaction. · Avoid salt substitutes or potassium supplements unless approved by your doctor, as this drug can increase potassium levels. · If you become pregnant or plan to become pregnant, contact your doctor immediately — this medication can harm an unborn baby. · Common side effects include dry cough, rash, and taste changes; these are usually harmless but inform your doctor if bothersome. · Stay well-hydrated but do not use potassium-containing electrolyte drinks without medical advice. · Do not take with NSAIDs (like ibuprofen) without consulting your doctor, as they may reduce effectiveness and increase kidney risks. · Regular blood tests to monitor kidney function and potassium levels are important while on this medication. |