Metoprolol Pharmaclan (Metoprolol)

Metoprolol is a selective β1‑adrenergic antagonist used in cardiovascular conditions.

• Hypertension: lowers blood pressure by reducing cardiac output and renin release.
• Angina pectoris: decreases myocardial oxygen demand, relieving chest pain.
• Chronic heart failure: improves survival and reduces hospitalisation by lowering heart rate and workload.
• Post‑myocardial infarction prophylaxis: reduces risk of recurrent events and arrhythmias.
• Certain cardiac arrhythmias: controls ventricular rate in atrial fibrillation and other supraventricular tachyarrhythmias.

• Metoprolol selectively blocks β1‑adrenergic receptors in cardiac tissue, inhibiting the effects of endogenous catecholamines. This reduces heart rate, myocardial contractility, and conduction velocity, leading to decreased cardiac output and lower renin secretion, which together lower systemic blood pressure and myocardial oxygen consumption.

Metoprolol may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Fatigue: feeling of tiredness or lack of energy.
• Dizziness: light‑headedness, especially on standing.
• Bradycardia: slower than normal heart rate.
• Cold extremities: reduced blood flow to hands and feet.
• Gastrointestinal upset: nausea, abdominal discomfort.
• Headache: mild to moderate pain.

Serious or Rare Side Effects

• Severe bradycardia or heart block requiring medical attention.
• Marked hypotension leading to fainting or shock.
• Bronchospasm, particularly in patients with asthma or COPD.
• Allergic reactions such as rash, itching, or angioedema.
• Depression or mood changes.
• Worsening heart failure symptoms.

Before initiating Metoprolol, clinicians should evaluate patient-specific factors and monitor therapy closely.

• Cardiac assessment: verify baseline heart rate and rhythm.
• Blood pressure monitoring: check for hypotension after dose changes.
• Respiratory caution: avoid in uncontrolled asthma or severe COPD.
• Renal/hepatic impairment: adjust dose if organ function is compromised.
• Discontinuation: taper gradually to prevent rebound tachycardia.
• Store at room temperature: keep in original container, protect from moisture and direct sunlight.

Metoprolol can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Other beta‑blockers: additive negative chronotropic effects.
• Non‑dihydropyridine calcium channel blockers (e.g., verapamil, diltiazem): risk of severe bradycardia and AV block.
• CYP2D6 inhibitors (e.g., quinidine, fluoxetine, paroxetine): increase metoprolol plasma levels.
• Clonidine: abrupt withdrawal may cause hypertensive crisis.

Moderate Interactions (Monitor Closely)

• Diuretics: may enhance hypotensive effect.
• Antidiabetic agents: mask hypoglycaemia symptoms.
• NSAIDs: can reduce antihypertensive efficacy.
• Potassium‑sparing diuretics: risk of hyperkalemia.
• Other antihypertensives: monitor for excessive blood pressure drop.