Metoprolol

Beta Blocker·Cardiovascular - Beta Blockers

AF rate control, angina, post-MI, HFrEF (succinate only)

PBSBETA BLOCKERBetaloc (Tartrate IR), Betaloc CR, Minax50 mg tabletS4+1

Max Dose

200 mg/day

Half-life

3–7 h

Asthma

CONTRAIND.

Bradycardia

RISK

Rapid Summary

Overview

Cardioselective (Beta-1) adrenergic antagonist. A staple of ward medicine for rate control, angina, and post-MI management.

Maximum Dose

Max 200 mg/day (often divided BD for tartrate form).

Clinical Focus

Tartrate (IR) is used for acute rate control. Succinate (CR) is used for chronic heart failure. Do not mix them up.

Bottom Line

Metoprolol is the first-line beta-blocker for heart failure and acute MI with both oral and IV formulations, but requires careful dose titration and must not be stopped abruptly.

Formulation & Access

Brand Names

Betaloc (Tartrate IR), Betaloc CR, Minax

Oral Routes

Tartrate Tablets (50 mg, 100 mg). Succinate CR Tablets (23.5 mg, 47 mg, 95 mg, 190 mg).

Parenteral

Ampoule (5 mg/5 mL) for IV administration (high risk of bradycardia/arrest).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

AF rate control, angina, post-MI, HFrEF (succinate only).

Clinical Place

Workhorse beta-blocker on the ward for rapid heart rates. First-line for post-MI cardioprotection.

Quick reference

Class & Role

Beta Blocker — Cardioselective (Beta-1) adrenergic antagonist.

Route / Formulation

Tartrate Tablets (50 mg, 100 mg). Succinate CR Tablets (23.5 mg, 47 mg, 95 mg, 190 mg). (Betaloc (Tartrate IR), Betaloc CR, Minax)

Usual Dose & Max

PO 25-50 mg (Tartrate) BD or TDS. May use IV 2.5-5 mg slowly (Specialist). Max 200 mg/day (often divided BD for tartrate form).

Key Indication Doses

AF / Rate Control (Acute): PO 25-50 mg (Tartrate) BD or TDS. May use IV 2.5-5 mg slowly (Specialist). Heart Failure (HFrEF): PO 11.75 mg or 23.5 mg (Succinate CR) OD. Titrate slowly to Max 190 mg OD. Post-MI / Angina: PO 50 mg (Tartrate) BD. Max 200 mg/day.

Best Uses

Metoprolol is the first-line beta-blocker for heart failure and acute MI with both oral and IV formulations, but requires careful dose titration and must not be stopped abruptly.

Avoid / Cautions

Severe asthma, 2nd/3rd degree heart block, sick sinus syndrome, uncompensated acute decompensated heart failure. Pregnancy Category C (risk of neonatal bradycardia).

Key Risks

Cardiovascular: Bradycardia, AV block, cardiogenic shock in acute overdose. Respiratory: Bronchospasm (despite being 'cardioselective', selectivity is lost at high doses). Endocrine: Can mask the physiological symptoms of hypoglycemia (tachycardia, tremor) in diabetics. Neurological: Fatigue, vivid dreams, cold extremities.

Key Interactions

Verapamil and Diltiazem. Concurrent use risks fatal asystole. CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) will significantly increase metoprolol levels and bradycardia risk.

Monitoring

Hold dose if HR < 50 bpm or systolic BP < 90 mmHg. Check before every administration. Baseline ECG to rule out existing heart block before initiation.

Clinical Pearl

Metoprolol Tartrate is immediate release (dosed BD/TDS). Metoprolol Succinate is controlled release (dosed OD). Succinate is the ONLY form proven to reduce mortality in Heart Failure.

Access

Betaloc (Tartrate IR), Betaloc CR, Minax50 mg tablet

Brand: Betaloc (Tartrate IR), Betaloc CR, Minax
Formulation: Tartrate Tablets (50 mg, 100 mg)

Metoprolol

Beta Blocker·Cardiovascular - Beta Blockers

AF rate control, angina, post-MI, HFrEF (succinate only)

PBSBETA BLOCKERBetaloc (Tartrate IR), Betaloc CR, Minax50 mg tabletS4+1

Max Dose

200 mg/day

Half-life

3–7 h

Asthma

CONTRAIND.

Bradycardia

RISK

Rapid Summary

Overview

Cardioselective (Beta-1) adrenergic antagonist. A staple of ward medicine for rate control, angina, and post-MI management.

Maximum Dose

Max 200 mg/day (often divided BD for tartrate form).

Clinical Focus

Tartrate (IR) is used for acute rate control. Succinate (CR) is used for chronic heart failure. Do not mix them up.

Bottom Line

Metoprolol is the first-line beta-blocker for heart failure and acute MI with both oral and IV formulations, but requires careful dose titration and must not be stopped abruptly.

Formulation & Access

Brand Names

Betaloc (Tartrate IR), Betaloc CR, Minax

Oral Routes

Tartrate Tablets (50 mg, 100 mg). Succinate CR Tablets (23.5 mg, 47 mg, 95 mg, 190 mg).

Parenteral

Ampoule (5 mg/5 mL) for IV administration (high risk of bradycardia/arrest).

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

AF rate control, angina, post-MI, HFrEF (succinate only).

Clinical Place

Workhorse beta-blocker on the ward for rapid heart rates. First-line for post-MI cardioprotection.

Quick reference

Class & Role

Beta Blocker — Cardioselective (Beta-1) adrenergic antagonist.

Route / Formulation

Tartrate Tablets (50 mg, 100 mg). Succinate CR Tablets (23.5 mg, 47 mg, 95 mg, 190 mg). (Betaloc (Tartrate IR), Betaloc CR, Minax)

Usual Dose & Max

PO 25-50 mg (Tartrate) BD or TDS. May use IV 2.5-5 mg slowly (Specialist). Max 200 mg/day (often divided BD for tartrate form).

Key Indication Doses

Best Uses

Metoprolol is the first-line beta-blocker for heart failure and acute MI with both oral and IV formulations, but requires careful dose titration and must not be stopped abruptly.

Avoid / Cautions

Severe asthma, 2nd/3rd degree heart block, sick sinus syndrome, uncompensated acute decompensated heart failure. Pregnancy Category C (risk of neonatal bradycardia).

Key Risks

Key Interactions

Verapamil and Diltiazem. Concurrent use risks fatal asystole. CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) will significantly increase metoprolol levels and bradycardia risk.

Monitoring

Hold dose if HR < 50 bpm or systolic BP < 90 mmHg. Check before every administration. Baseline ECG to rule out existing heart block before initiation.

Clinical Pearl

Metoprolol Tartrate is immediate release (dosed BD/TDS). Metoprolol Succinate is controlled release (dosed OD). Succinate is the ONLY form proven to reduce mortality in Heart Failure.

Access

Betaloc (Tartrate IR), Betaloc CR, Minax50 mg tablet

Brand: Betaloc (Tartrate IR), Betaloc CR, Minax
Formulation: Tartrate Tablets (50 mg, 100 mg)