When to check Blood Pressure Monitoring (BPM) after starting Angiotensin-Converting Enzyme Inhibitor (ACEI)?

When to Check BMP After Starting ACEi

BMP should be checked 1-2 weeks after initiating ACEi therapy, with additional monitoring needed based on baseline renal function and risk factors. 1

Initial Monitoring Schedule

• Check baseline renal function and electrolytes before starting ACEi therapy 1
• Obtain follow-up BMP 1-2 weeks after initiation of ACEi 1
• Repeat BMP 1-2 weeks after each dose increase or titration 1
• Continue monitoring "frequently and serially until creatinine and potassium have plateaued" 1
• Once stable, monitor every 3-4 months for long-term maintenance 1

Risk-Based Monitoring Approach

Higher Risk Patients (more frequent monitoring needed):

• Patients with chronic kidney disease (CKD): Check BMP at baseline, 1 week, and 2 weeks after initiation 1
• Patients with heart failure: Monitor within 1-2 weeks of initiation 1
• Elderly patients: Higher risk of renal dysfunction with lower GFR at baseline 2
• Patients on concomitant medications:
  • Diuretics: Increased risk of dehydration and renal dysfunction 1
  • Aldosterone antagonists: Higher risk of hyperkalemia 1
  • NSAIDs: Can worsen renal function when combined with ACEi 2

Parameters to Monitor and Action Thresholds

Creatinine:

• Expect a possible rise in serum creatinine of up to 30% (NICE guideline) or 50% (ESC/SIGN guidelines) from baseline 1
• If creatinine increases >30-50% from baseline or >266 μmol/L, consider:
  • Review other medications that may affect renal function 1
  • Reduce ACEi dose by 50% 1
  • Recheck renal function in 1-2 weeks 1
• Discontinue ACEi if creatinine increases by 100% or more, or exceeds 310 μmol/L 1

Potassium:

• Monitor for hyperkalemia, especially in CKD patients (5x higher risk) 2
• If potassium reaches 5.5-5.9 mmol/L, reduce ACEi dose by 50% 1
• If potassium exceeds 6.0 mmol/L, discontinue ACEi 1

Blood Pressure:

• First-dose hypotension may occur within hours of initial dose 3
• High-risk patients (heart failure, elderly, on multiple antihypertensives) should be observed for at least 6 hours after first dose 3
• Consider home BP monitoring as it may be more reliable than clinic measurements for assessing drug effects 4

Common Pitfalls and Caveats

• Undermonitoring: Nearly one-third of patients on ACEi/ARBs do not receive yearly laboratory monitoring 5
• Early discontinuation: An early rise in creatinine (up to 30%) is expected and not necessarily a reason to stop therapy 2
• First-dose effects: Severe hypotension can occur with first dose in high-risk patients (heart failure, elderly, volume depleted) 3
• Dehydration risk: Concurrent diuretic use requires careful monitoring for volume depletion 1
• Drug interactions: Avoid triple therapy with ACEi, ARB, and direct renin inhibitors due to increased risk of renal dysfunction 1
• Medication adherence: Ensure patients understand the importance of regular monitoring 5

Special Considerations

• In patients with diabetes and CKD, early rise in creatinine is associated with long-term renoprotection 2
• Continue ACEi even when eGFR falls below 30 ml/min/1.73m² unless there are specific contraindications 1
• Patients with bilateral renal artery stenosis are at higher risk for acute kidney injury with ACEi 1
• Patients on combination therapy (ACEi + ARB) require more vigilant monitoring for renal dysfunction and hyperkalemia 6