Captopril
Mechanism :
Captopril is a specific competitive inhibitor of angiotensin I-converting enzyme (ACE), the enzyme responsible for the conversion of angiotensin I to angiotensin II.
Indication :
- Hypertension
- Congestive cardiac failure
Contraindications :
Captopril is contraindicated in patients who are hypersensitive to this product or any other angiotensin-converting enzyme inhibitor. Avoid in neonates, in volume depletion and renovascular disease.
Dosing :
Premature neonates:
0.01 mg/kg orally 8-12 hourly;
Neonates:
Initially 0.05-0.1 mg/kg/dose orally 1-3 times and increase upto 0.5 mg/kg/dose 1-4 times daily;
Infants:
0.15-0.3 mg/kg orally, Increase upto 6 mg/kg/day in 1-4 divided doses;
Child:
Initially 0.3-0.5 kg/dose orally and increase upto 6 mg/kg/day in 2-4 divided doses;
Older children:
6.25-12.5 mg/dose orally, 1-2 times a day and increased upto a maximum of 6 mg/kg/day in 2-4 divided doses.
Adolescents:
12.5-25 mg/dose 1-2 times a day and increased by 25 mg/dose every 1-2 weeks upto a maximum of 450 mg/day.
Adverse Effect :
Neutropenia, agranulocytosis, anemia, thrombocytopenia, pancytopenia, rash, pruritus, fever, arthralgia, eosinophilia, hypotension, angioedema, cough.
Interaction :
Diuretics: A precipitous reduction of blood pressure usually within the first hour of receiving the initial dose of captopril.
Potassium-sparing diuretics such as Spironolactone, Triamterene, or Amiloride: Since captopril decreases aldosterone production, elevation of serum potassium may occur.
Nonsteroidal Anti-Inflammatory Agents: Reduces the antihypertensive effect of captopril
Lithium: Increased serum lithium levels and symptoms of lithium toxicity.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Start low – adjust according to response |
| 10-20 | Start low – adjust according to response |
| <10 | Start low – adjust according to response |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Dialysed. Dose as in GFR<10 mL/ min |
| HDF/High flux | Dialysed. Dose as in GFR<10 mL/ min |
| CAV/VVHD | Dialysed. Dose as in GFR=10– 20 mL/min |
Hepatic Dose :
No dosage adjustments are recommended.