Obtain baseline BP, creatinine/eGFR, potassium and sodium and check for pregnancy, volume depletion, suspected renovascular disease and interactions.
NHS SPS: repeat renal function and electrolytes 1–2 weeks after initiation or dose change in most adults; more promptly in higher-risk patients and follow the indication-specific advice.
Small creatinine changes can be expected; assess larger rises, hyperkalaemia and AKI in context rather than stopping all renin-angiotensin system inhibitors indiscriminately.

UK source: guidance / safety update. Only the specific points above were source checked. All other historical text, doses and procedural instructions remain unvalidated: verify current BNF/BNFC and local guidance before clinical use.

Related Subjects: |Hypertension |Acute Heart Failure |Chronic Heart Failure

⚠️ First-dose hypotension is common. 💡 Start at the lowest dose, ideally at night with the patient in bed. More frequent when used for heart failure than for hypertension. If it occurs → lie patient flat, raise legs, and give IV fluids if BP remains low.

💊 About: Always check the BNF link here

🔹 Competitively inhibits angiotensin-converting enzyme (ACE).
🛑 Prevents formation of angiotensin II, a potent vasoconstrictor.
⬆️ Increases bradykinin → cough and angioedema.
📉 Reduces BP without reflex tachycardia.
📊 Always check U&Es, document starting BP, and identify a target BP before initiation.

🎯 Indications / Dose

💔 Heart failure: Start 6.25 mg PO TDS → titrate to max 50 mg TDS.
❤️ Hypertension: Start 12.5 mg PO TDS → titrate to max 50 mg TDS.
🧪 Diabetes with nephropathy: Start 6.25 mg PO TDS → titrate to max 50 mg TDS.

⚠️ Cautions

Less effective as monotherapy in African-Caribbean patients (consider CCBs or thiazides first per NICE guidance).

⛔ Contraindications

🚫 Pregnancy and breastfeeding – teratogenic.
⚠️ Severe aortic stenosis or hypertrophic cardiomyopathy.
🚫 Bilateral renal artery stenosis.
⚠️ Pre-existing hyperkalaemia.

🔄 Interactions

⚠️ With alteplase (tPA) → angioneurotic oedema risk in acute stroke thrombolysis.
❌ Avoid NSAIDs (reduce efficacy, worsen renal function).
⬆️ Hyperkalaemia risk when combined with potassium-sparing diuretics, ARBs, or supplements.

⚠️ Side Effects

📉 Postural hypotension (especially first dose, see above).
🤢 Nausea, vomiting.
💨 Cough (bradykinin-related).
😮 Angioedema (rare but serious).
👅 Altered taste (metallic taste).
💧 Worsening renal function in bilateral renal artery stenosis.
🧪 Hyperkalaemia.

📋 Monitoring

🔍 Check renal function & electrolytes at 4 days and 2 weeks after initiation.
📈 Repeat 1 week after any dose increase.
⚠️ Stop or reduce if creatinine ↑ >30% or K⁺ >6.0 mmol/L.

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Captopri 💊 ✅

🩺 UK targeted safety update — 4 November 2026