1. Clinical & Scientific Overview
Metoprolol (Metoprolol Succinate ER & Metoprolol Tartrate IR) (TIP-MED-000007, Reference Code [3.7]) is classified under
Cardiovascular & Antithrombotic Medicines (Ch 03) as a Cardioselective Beta-1 Adrenergic Blocker.
Within the Indian regulatory and compendial framework, it is governed under Schedule H Prescription Drug • NLEM 2022 Core Essential Medicine.
Metolar (Cipla), Betaloc (AstraZeneca), Starpress XL (Lupin), Prolomet XL (Sun Pharma)
Extended-Release (Metoprolol Succinate ER/XL): 12.5 mg, 25 mg, 50 mg, 100 mg, 200 mg (equivalent to tartrate). Immediate-Release (Metoprolol Tartrate IR): 25 mg, 50 mg, 100 mg; IV Injection: 1 mg/mL
3. Mechanism of Action & Pharmacodynamics
Competitively antagonizes catecholamine (noradrenaline/adrenaline) stimulation of cardiac beta-1 adrenoceptors in the SA node, AV node, and ventricular myocardium (without intrinsic sympathomimetic activity), reducing Phase 4 pacemaker slope, heart rate, contractility, cardiac output, and renin release from juxtaglomerular cells.
4. Therapeutic Indications & Evidence-Supported Uses
- HFrEF (Heart Failure with Reduced Ejection Fraction — Metoprolol Succinate ER ONLY)
- Chronic stable angina, post-myocardial infarction secondary prevention, and hypertension
- Rate control in atrial fibrillation / supraventricular tachyarrhythmias
5. Educational Dosage Context, Formulations & Administration
Educational Dosing & Regimen Summary: HFrEF (Succinate ER): Start 12.5–25 mg once daily; double every 2 weeks as tolerated to target 200 mg once daily. Hypertension/Angina: 25–100 mg once daily (Succinate ER) or in 2 divided doses (Tartrate IR).
Administration & Meal Timing: Oral; Metoprolol Tartrate IR should be taken with or immediately after a meal; Metoprolol Succinate ER once daily (scored multi-pellet tablets may be halved if scored, but never crushed or chewed).
6. Pharmacokinetics, Metabolism & Renal/Hepatic Adjustment
Absorption, distribution, metabolism, and excretion follow class pharmacokinetic profile; verify patient renal/hepatic function.
Reduce dose or titrate slowly in hepatic cirrhosis due to decreased first-pass clearance.
No dose adjustment required in renal impairment.
Reduce dose or titrate slowly in hepatic cirrhosis due to decreased first-pass clearance.
7. Contraindications, Precautions & High-Risk Warnings
- Sinus bradycardia (<50 bpm), 2nd or 3rd degree AV heart block, or sick sinus syndrome without pacemaker
- Decompensated acute heart failure or cardiogenic shock
- Severe peripheral arterial disease or active severe bronchospasm
Key Clinical Precautions: Reduce dose or titrate slowly in hepatic cirrhosis due to decreased first-pass clearance.
8. Adverse Effects Profile
- Sinus bradycardia, fatigue, dizziness, and cold extremities
- Masking of sympathetic hypoglycaemia symptoms (tachycardia/tremor) in diabetics
- Bronchospasm at high doses (>100 mg/day) due to relative loss of beta-1 selectivity
- Rebound tachycardia, angina, or myocardial infarction if discontinued abruptly
9. Major Drug–Drug, Drug–Food & Drug–Herb Interactions
- Non-DHP CCBs (Verapamil, Diltiazem) or Digoxin: additive AV nodal depression, severe bradycardia, or complete heart block
- CYP2D6 inhibitors (Fluoxetine, Paroxetine, Bupropion, Quinidine): 3–4x elevation in Metoprolol levels
- Clonidine: Abrupt Clonidine withdrawal during beta-blockade triggers severe unopposed alpha-mediated rebound hypertensive crisis
- Insulin & Sulfonylureas: Masks adrenergic hypoglycaemia warning symptoms (tremor, palpitations) while sweating remains preserved
10. Clinical Monitoring, Patient Counselling & Storage
Clinical & Laboratory Monitoring: Monitor clinical response, baseline renal/hepatic parameters, and relevant serum biomarkers.
Pharmacist Patient Counselling Points:
- NEVER stop Metoprolol abruptly; taper gradually over 1–2 weeks to prevent rebound angina or myocardial infarction.
- In diabetic patients, note that fast heartbeat and tremor during low blood sugar may be masked, though sweating still occurs.
- Do not crush or chew Extended-Release (XL/ER) tablets.
Storage, Stability & Dispensing Safeguards: Store below 30°C protected from light and moisture.
11. Visual Pharmacology & Mechanism Diagram (svg-v339-01-adme-12-step-journey)
12. Authoritative References, Regulatory Sources & Editorial Disclaimer
Primary Compendial & Guideline Reference: Indian Pharmacopoeia (IP 2026) • NLEM 2022 (MoHFW) • CDSCO Approved Prescribing Information
Official Verification Portals: Indian Pharmacopoeia Commission (IPC) & National Formulary of India (NFI) • Central Drugs Standard Control Organization (CDSCO) • Ministry of Health & Family Welfare — NLEM 2022 • NCBI Bookshelf / StatPearls Pharmacology Reference • DailyMed (US FDA Official Prescribing Reference)
Last Medically & Pharmaceutically Reviewed: 2026-11-10 • Verification Status: VERIFIED_EDUCATIONAL_CONTENT
Educational & Clinical Disclaimer: This reference profile is published solely for pharmacy education, academic study, and professional clinical reference. It does not substitute for patient-specific clinical judgement, qualified specialist oncology/medical supervision, or official CDSCO/IP prescribing information. Never self-medicate with prescription, Schedule H/H1/X, NDPS, or oncology medicines.