ACE Inhibitors: The Dispensing Safety Checklist

📋 First Dispense Essentials

Mandatory items to issue

• Confirm baseline blood tests have been completed before starting: eGFR (estimated glomerular filtration rate) or creatinine, potassium, and sodium. ACE inhibitors should not normally be initiated if potassium is above 5.0 mmol/L.
• Provide or confirm sick day rules advice. Ensure the patient knows to temporarily stop their ACE inhibitor during any acute illness causing dehydration, including vomiting, diarrhoea, or fever. Supply a sick day rules card if one is available locally.
• Counsel on first-dose hypotension. Blood pressure may fall significantly after the first dose, particularly in patients with heart failure, volume depletion, or those on high-dose diuretics. Advise taking the first dose at bedtime and rising slowly after sitting or lying down.

Baseline clinical checks

• eGFR or creatinine: required at baseline. A small rise in creatinine after starting is expected and acceptable. A rise of more than 30% or a fall in eGFR of more than 25% after starting may indicate renovascular disease and requires urgent prescriber review.
• Potassium: ACE inhibitors reduce aldosterone, causing potassium retention. Do not normally initiate if potassium is above 5.0 mmol/L. Risk of dangerous hyperkalaemia increases significantly when combined with potassium-sparing diuretics, spironolactone, or NSAIDs (non-steroidal anti-inflammatory drugs).
• Blood pressure: record baseline blood pressure. First-dose hypotension is a particular risk in heart failure, volume depletion, or high-dose diuretic use. Seek specialist advice before starting if systolic blood pressure is below 90 mmHg.
• Consider specialist advice before starting in patients with eGFR below 30 mL/min/1.73m2, known renovascular disease, or hyponatraemia (sodium below 130 mmol/L).

Key risks and lifestyle traps

• NSAIDs (including ibuprofen, naproxen, and analgesic-dose aspirin) reduce the renal protective effects of ACE inhibitors, worsen kidney function, and increase the risk of hyperkalaemia. Advise patients not to buy ibuprofen or other NSAIDs without checking first.
• Potassium-sparing diuretics (amiloride) and aldosterone antagonists (spironolactone, eplerenone): combination with ACE inhibitors increases the risk of hyperkalaemia substantially. Monitor potassium closely in any patient on both. Combination therapy requires careful monitoring and would not normally be initiated if baseline potassium exceeds 5.0 mmol/L.
• Lithium: ACE inhibitors reduce lithium excretion, raising lithium levels and increasing toxicity risk. If an ACE inhibitor is started or stopped in a patient taking lithium, monitor lithium levels closely.
• Combined ACE inhibitor and ARB (angiotensin receptor blocker) therapy is not routinely recommended. The combination increases the risk of acute kidney injury and hyperkalaemia without meaningful additional benefit for most patients.
• Dry cough affects approximately 5 to 20% of patients and is more common in women and people of East Asian origin. It is frequently missed as a drug side effect. Many patients stop taking their ACE inhibitor without telling anyone. If a patient reports a persistent dry cough, refer to the prescriber; a switch to an ARB usually resolves it.
• Angioedema is rare but life-threatening. It causes swelling of the face, lips, tongue, or throat and can occur at any time during treatment, including years after starting. It is more common in people of African and Caribbean descent. ACE inhibitors must be stopped immediately and never restarted after angioedema.

First dispense script

🔄 Repeat Dispense Screen

Mandatory documentation

• Record the dose dispensed on every occasion. Note any recent dose changes.
• Record whether renal function and electrolyte monitoring appears current. Document any interventions made if monitoring appears overdue.
• Note any newly added interacting medicines, particularly NSAIDs, potassium-sparing diuretics, or spironolactone.

Ongoing clinical checks

• Heart failure: eGFR or creatinine, potassium, and sodium within 1 to 2 weeks of starting or dose change (within 5 to 7 days if risk factors such as age over 60, chronic kidney disease, or diabetes). Then monthly for 3 months, then every 6 months. Repeat at any time the patient is acutely unwell.
• Hypertension and post-myocardial infarction: eGFR, potassium, and sodium within 1 to 2 weeks (7 days if risk factors). Then annually. Blood pressure within 1 month of starting.
• Check for newly prescribed NSAIDs, potassium supplements, or potassium-sparing diuretics at every dispense.
• If the patient is on lithium, confirm whether lithium levels have been checked since the ACE inhibitor was started or most recently adjusted.

Ask the patient at the counter

• "Have you noticed a new dry cough since starting this medicine?"
• "Have you had any vomiting, diarrhoea, or been unwell recently? Did you stop your medicine while you were ill?" Confirm the patient understands sick day rules if dehydration or gastrointestinal illness has occurred since the last supply.
• "Have you started any new medicines, including anything bought without a prescription?"

Lifestyle and surgical alerts

• Sick day rules: withhold the ACE inhibitor during any dehydrating illness. Restart when eating and drinking normally for 24 to 48 hours. Patients taking multiple sick day rule medicines (sometimes known as SADMAN medicines: Sulphonylureas, ACE inhibitors/ARBs, Diuretics, Metformin, Aspirin/NSAIDs, and NSAIDs) are at particularly high risk of acute kidney injury during illness.
• Avoid NSAIDs, including OTC ibuprofen, unless specifically agreed with the prescriber.
• Patients should rise slowly from sitting or lying to reduce the risk of dizziness from low blood pressure.
• Pregnancy: ACE inhibitors should be avoided during pregnancy. Women of childbearing potential should be advised to discuss with their prescriber before planning pregnancy. Stop immediately if pregnancy is confirmed and refer urgently.

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