How to switch a patient from ramipril (Angiotensin-Converting Enzyme inhibitor) 5mg orally (po) twice daily (bid) to telmisartan (Angiotensin II receptor blocker)?

Switching from Ramipril 5mg BID to Telmisartan

When switching from ramipril 5mg twice daily to telmisartan, start with telmisartan 40mg once daily in the morning with a 24-36 hour washout period between medications.

Rationale for Switching

• ACE inhibitors (like ramipril) and ARBs (like telmisartan) both target the renin-angiotensin system but through different mechanisms
• Common reasons for switching from an ACE inhibitor to an ARB include:
  • ACE inhibitor-induced cough (occurs in up to 20% of patients)
  • Angioedema (occurs in <1% of patients but more frequently in Black patients) 1
  • Need for once-daily dosing to improve adherence

Switching Protocol

1. Washout Period:

   • Allow a 24-36 hour washout period between the last dose of ramipril and the first dose of telmisartan 1
   • This minimizes the risk of adverse effects from overlapping medications

2. Initial Telmisartan Dosing:

   • Start with telmisartan 40mg once daily in the morning
   • This is an appropriate starting dose for patients previously on moderate doses of ACE inhibitors 1, 2
   • Morning dosing has been shown to be effective for 24-hour blood pressure control 3

3. Monitoring After Switch:

   • Check blood pressure within 2-4 weeks of initiating telmisartan 1
   • Monitor renal function (serum creatinine, eGFR) and serum potassium within 1-2 weeks of initiating telmisartan 1
   • Assess for potential side effects at follow-up visits

Dose Titration

• If blood pressure control is inadequate after 2-4 weeks, consider increasing to telmisartan 80mg once daily 4, 1
• Maximum dose of telmisartan is 80mg daily for hypertension 2
• Dose adjustments should not be made more frequently than every 2 weeks 1

Special Considerations

• Renal Impairment: Use caution when switching in patients with renal impairment (eGFR <30 mL/min/1.73m² or serum creatinine >2.5 mg/dL in men or >2.0 mg/dL in women) 1
• Elderly Patients: Consider starting with a lower dose (20mg) in elderly patients 1
• Bilateral Renal Artery Stenosis: Use with caution in these patients 1

Common Pitfalls to Avoid

1. Inadequate Washout Period: Failing to allow sufficient time between medications can increase risk of adverse effects
2. Underdosing: Starting with too low a dose (e.g., 20mg) may result in suboptimal blood pressure control 1
3. Dual RAAS Blockade: Never combine telmisartan with another ACE inhibitor or ARB due to increased risk of renal dysfunction, hyperkalemia, and hypotension 4, 1
4. Insufficient Monitoring: Failure to check blood pressure, renal function, and electrolytes after switching

Expected Outcomes

• Telmisartan provides effective 24-hour blood pressure control with once-daily dosing 2, 3
• Telmisartan has a similar efficacy profile to ACE inhibitors but with fewer side effects like cough 2
• The long half-life of telmisartan (24 hours) provides more consistent blood pressure control than the shorter half-life of ramipril 2

By following this protocol, you can safely and effectively transition patients from ramipril 5mg twice daily to telmisartan with minimal risk of adverse events while maintaining blood pressure control.