Should telmisartan (angiotensin II receptor antagonist) be omitted on the day of surgery?

Perioperative Management of Telmisartan

Telmisartan should be withheld on the day of surgery to reduce the risk of intraoperative hypotension. 1

Rationale for Withholding Telmisartan

Telmisartan is an angiotensin II receptor blocker (ARB) with a long half-life of 24 hours 2, 3. While ARBs are effective for hypertension management, they present specific perioperative concerns:

• The 2024 AHA/ACC guideline states that discontinuation of ARBs perioperatively may be considered (Class IIb, Level of Evidence C-LD) 1
• Patients receiving ARBs on the morning of surgery experience more frequent and severe hypotensive episodes during anesthesia induction compared to those who discontinue the medication the day before surgery 4
• Blockade of the renin-angiotensin system increases the potential hypotensive effect of anesthetic induction 4

Evidence-Based Approach

The decision to withhold telmisartan is supported by multiple guidelines:

• The 2014 ACC/AHA guideline provides a Class IIa recommendation (Level of Evidence B) that if ARBs are held before surgery, they should be restarted as soon as clinically feasible postoperatively 1
• The European Society of Cardiology guidelines note that in patients with hypertension, antihypertensive therapy should be continued up to the morning of surgery and restarted promptly post-operatively, but caution is needed with ARBs 1

Perioperative Management Algorithm

1. Pre-operative (day before surgery):

   • Withhold telmisartan on the day of surgery
   • Continue other antihypertensive medications as appropriate
   • Monitor blood pressure

2. Intraoperative:

   • Be prepared for potential hypotension
   • Have vasopressors available if needed
   • Maintain mean arterial pressure ≥60-65 mmHg or systolic BP ≥90 mmHg 1

3. Post-operative:

   • Restart telmisartan as soon as clinically feasible once the patient is hemodynamically stable 1
   • Monitor blood pressure closely during the transition period

Important Considerations and Caveats

• Long half-life: Telmisartan has the longest half-life among ARBs (24 hours), which means its effects may persist even when withheld on the day of surgery 2, 3, 5
• Rebound hypertension: Unlike beta-blockers or clonidine, abrupt discontinuation of ARBs does not cause dangerous rebound hypertension 1, 6
• Hemodynamic stability: Patients on ARBs show more labile hemodynamic profiles during anesthesia 6
• Specific risk: Research has demonstrated that continuing ARBs increases the risk, duration, and severity of hypotensive episodes during anesthesia induction 4

Special Situations

• Emergency surgery: If surgery cannot be delayed, be prepared for more aggressive management of intraoperative hypotension
• High cardiovascular risk patients: Even in these patients, the risk of intraoperative hypotension generally outweighs the benefit of continuing telmisartan on the day of surgery

By withholding telmisartan on the day of surgery and restarting it postoperatively when the patient is hemodynamically stable, you can minimize the risk of significant intraoperative hypotension while maintaining long-term blood pressure control.