In a patient with hypotension, is metoprolol tartrate (beta-blocker) or metoprolol succinate preferred?

Metoprolol Formulation Selection in Hypotension

Neither metoprolol tartrate nor metoprolol succinate should be administered to patients with hypotension, as both formulations are contraindicated when systolic blood pressure is below 100 mmHg with symptoms. 1, 2

Absolute Contraindications for Both Formulations

Both metoprolol tartrate and metoprolol succinate share identical contraindications that preclude their use in hypotensive patients:

• Systolic blood pressure <100 mmHg with symptoms (dizziness, lightheadedness, altered mental status, or signs of hypoperfusion) 1, 2
• Signs of heart failure, low output state, or decompensated heart failure 1, 2
• Symptomatic bradycardia (heart rate <50-60 bpm with symptoms) 1, 2
• Second or third-degree AV block without a functioning pacemaker 1, 2
• Active asthma or severe reactive airway disease 1

Why This Question Has No Valid Answer

The premise of choosing between formulations in hypotension is clinically inappropriate because:

• Beta-blockers cause hypotension as a primary adverse effect through negative inotropic effects and reduced cardiac output 1
• The American Heart Association explicitly lists hypotension as a side effect requiring dose adjustment or discontinuation 1
• Both formulations have identical hemodynamic effects - the only difference is pharmacokinetic (immediate-release vs extended-release), not pharmacodynamic 2, 3

Clinical Management of Hypotension in Patients Already on Metoprolol

If a patient develops hypotension while taking either formulation:

• Hold the medication immediately until blood pressure stabilizes above 100 mmHg systolic without symptoms 2
• Assess for signs of hypoperfusion: oliguria, altered mental status, cool extremities, or elevated lactate 2
• Never abruptly discontinue long-term therapy - taper by 25-50% every 1-2 weeks if discontinuation is necessary, as abrupt cessation causes severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias with 50% mortality in one study 2
• Consider dose reduction by 50% rather than complete discontinuation once blood pressure improves, to maintain mortality benefit in patients with heart failure or post-MI 2

Common Pitfall to Avoid

Do not assume that switching from tartrate to succinate (or vice versa) will solve hypotension. Both formulations contain the same active drug with identical beta-blocking properties and will produce the same blood pressure-lowering effects at equivalent doses. 2, 3