captopril: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
captopril: clinical details
Prescribing considerations
- Assess volume status and risk of first-exposure hypotension, particularly with heart failure, intensive diuretic treatment, vomiting, diarrhoea or dialysis.
- Use particular caution in renal impairment, suspected renovascular disease, ischaemic cardiovascular or cerebrovascular disease, older people and neonates.
- Review medicines that raise potassium, impair renal function, lower blood pressure or increase angioedema risk.
- Captopril-associated angioedema may have delayed onset and may be bradykinin-mediated.
Contraindications and cautions
- Hypersensitivity to captopril, another ACE inhibitor or a formulation excipient.
- Previous ACE-inhibitor-associated angioedema or hereditary/idiopathic angioedema.
- Second or third trimester of pregnancy.
- Concurrent aliskiren in patients with diabetes or qualifying renal impairment.
- Breastfeeding wording differs between selected products: sugar-free product information lists lactation as a contraindication, while other selected products allow conditional consideration with an older infant.
Monitoring
- Record baseline blood pressure, renal function, potassium and sodium.
- Repeat blood pressure, renal function and electrolytes after initiation or treatment changes and during acute illness that may compromise renal function.
- Continue periodic monitoring once stable, with greater frequency for renal impairment, diabetes, older age, heart failure or interacting medicines.
Clinical pharmacology
Captopril is an active, competitive ACE inhibitor that does not require metabolic activation. It suppresses angiotensin II and aldosterone formation and increases bradykinin activity. It is predominantly cleared through the kidneys, so impaired renal function can cause accumulation.
Formulation and product differences
- Selected products are oral solutions available in different concentrations and as sugar-free or non-sugar-free presentations.
- Measuring devices, excipient quantities, storage after opening, feeding-tube compatibility and instructions such as shaking may differ by product.
- Some solutions contain sodium benzoate, which is relevant in newborn babies because it may worsen jaundice.
- Avoid unreviewed substitution between concentrations or formulations; verify the exact product and measuring device.
captopril preparations and strengths
Oral solution
Route: Oral
Strengths: 5 mg/5 mL, 25 mg/5 mL
captopril interactions
Important interactions include:
Potassium supplements, potassium-containing salt substitutes and potassium-sparing diuretics
May cause clinically important hyperkalaemia; potassium requires close monitoring if combined.
Angiotensin receptor blockers or aliskiren
Dual renin–angiotensin system blockade increases hypotension, hyperkalaemia and kidney-injury risk; some aliskiren combinations are contraindicated.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.