What intravenous (IV) beta-blocker can replace oral metoprolol tartrate (metoprolol) for an elderly male patient with a hip fracture who declines oral medication before surgery?

IV Beta-Blocker Replacement for Oral Metoprolol Before Hip Fracture Surgery

For an elderly patient on chronic oral metoprolol tartrate 25 mg who declines oral medication before hip fracture surgery, administer IV metoprolol 2.5 mg as a slow bolus over 1-2 minutes, which can be repeated every 5 minutes as needed up to a maximum total dose of 15 mg, based on hemodynamic response. 1, 2

Critical Context: Continue vs. Initiate Beta-Blockade

This patient is already on chronic beta-blocker therapy, which fundamentally changes the perioperative approach:

• Continuation of existing beta-blocker therapy is a Class I recommendation (should be done in all cases) by the ACC/AHA, regardless of the indication for the beta-blocker. 3

• The risk of rebound hypertension and coronary ischemia from abrupt beta-blocker withdrawal is substantial, even in patients taking beta-blockers for non-cardiac indications. 3

• Beta-blocker withdrawal is associated with a 2.7-fold increased risk of 1-year mortality compared to continuous use. 2

• This is completely different from initiating high-dose beta-blockers on the day of surgery in beta-blocker-naïve patients, which is harmful (Class III recommendation). 3

Standard IV Metoprolol Dosing Protocol

Initial Administration

• Start with 2.5-5 mg IV bolus administered slowly over 1-2 minutes. 1, 2, 4

• Repeat every 5 minutes as needed based on hemodynamic response. 1, 2

• Maximum total dose is 15 mg (three 5 mg boluses). 1, 2, 4

Dosing Rationale

• The patient's oral dose of metoprolol tartrate 25 mg daily is relatively low, so starting with the conservative 2.5 mg IV dose is appropriate. 2

• There is no direct mathematical conversion from oral extended-release to IV metoprolol; titrate based on clinical response rather than attempting dose equivalence. 2

• IV metoprolol has approximately 3-fold greater bioavailability than oral metoprolol due to first-pass metabolism. 2

Mandatory Pre-Administration Safety Checks

Before administering any IV metoprolol, verify the patient does NOT have: 1, 2

• Signs of heart failure, low output state, or decompensated heart failure
• Systolic blood pressure <100 mmHg (some sources use <120 mmHg for acute MI)
• Heart rate <50 bpm (some sources use <60 bpm)
• Second or third-degree heart block or PR interval >0.24 seconds
• Active asthma or reactive airway disease
• Evidence of cardiogenic shock risk

For elderly patients specifically, age >70 years is a risk factor for cardiogenic shock with IV beta-blockers, so use extra caution and consider starting with the lower 2.5 mg dose. 2

Required Monitoring During IV Administration

• Continuous heart rate monitoring 2
• Frequent blood pressure checks 2
• Continuous ECG monitoring 2
• Auscultation for new rales (pulmonary congestion) 2
• Auscultation for bronchospasm 2

Transition Back to Oral Therapy

• Start oral metoprolol tartrate 15 minutes after the last IV dose, rather than waiting longer. 2

• Initial oral dose should be 25-50 mg every 6 hours for 48 hours, then transition to the patient's usual twice-daily regimen. 1, 2

• Do not return directly to extended-release formulation immediately; use immediate-release (tartrate) initially. 2

Alternative IV Beta-Blocker: Esmolol

If the patient is at higher risk for hemodynamic instability, consider esmolol instead of IV metoprolol: 1

• Esmolol infusion: 100-300 mcg/kg/min starting after surgery 1

• Advantages: ultra-short half-life (9 minutes) allows rapid titration and quick reversal if hypotension or bradycardia develops 1

• Can transition to oral metoprolol 25-50 mg the following morning 1

Alternative IV Beta-Blocker: Atenolol

IV atenolol 5-10 mg can be administered 30 minutes prior to surgery: 1

• Used in multiple perioperative studies with good safety profile 1

• Can be repeated every 30 minutes up to maximum of 5 mg per dose 1

Critical Pitfalls to Avoid

• Never administer the full 15 mg as a single rapid bolus – this significantly increases hypotension and bradycardia risk. 2

• Do not give IV metoprolol if the patient has any signs of decompensated heart failure – wait until clinical stabilization. 2

• Do not assume the patient can tolerate the same total daily dose IV as oral – IV bioavailability is much higher. 2

• In hip fracture patients, be especially vigilant for occult blood loss and hypovolemia, which increases risk of hypotension with beta-blockers. 2

Special Considerations for Orthopedic Surgery

• Hip fracture repair is included in the orthopedic surgery category where perioperative beta-blockade has been studied. 1

• The 2014 ACC/AHA systematic review included 16% orthopedic procedures in the DECREASE-IV trial. 1

• Continuation of chronic beta-blocker therapy in orthopedic surgery patients is supported by multiple guidelines. 1, 3