Metoprolol Pharmaclan (Metoprolol)

Metoprolol is a selective β1‑blocker that acts on the cardiovascular system to control blood pressure and reduce cardiac workload.

• Hypertension: lowers systolic and diastolic pressure by reducing heart rate and contractility.
• Angina pectoris: decreases myocardial oxygen demand, relieving chest pain during exertion.
• Heart failure: improves survival and symptoms by moderating cardiac output and neuro‑hormonal activation.
• Post‑myocardial infarction: reduces risk of recurrent ischemic events and mortality.

• Metoprolol selectively antagonises β1‑adrenergic receptors in cardiac tissue, inhibiting catecholamine‑induced stimulation of adenylate cyclase. This reduces intracellular cyclic AMP, leading to decreased calcium influx, slower sino‑atrial node firing, lower myocardial contractility, and reduced cardiac output, which together lower arterial 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 or light‑headedness, especially on standing.
• Bradycardia: slower than normal heart rate.
• Cold extremities: reduced peripheral circulation.
• Gastrointestinal upset: nausea, abdominal discomfort.
• Headache: mild to moderate intensity.

Serious or Rare Side Effects

• Severe bradycardia or heart block requiring medical attention.
• Marked hypotension leading to fainting or shock.
• Bronchospasm in patients with reactive airway disease.
• Acute heart failure exacerbation.
• Allergic reactions such as rash, pruritus or angio‑edema.

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 regularly to avoid excessive hypotension.
• Concomitant beta‑blockers: avoid duplicate therapy unless specifically indicated.
• Renal/hepatic impairment: consider dose adjustment in severe dysfunction.
• Discontinuation: taper gradually to prevent rebound hypertension or tachycardia.
• Store at below 25°C: keep in the original packaging, 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 bradycardia and hypotension.
• Calcium‑channel blockers (verapamil, diltiazem): enhanced negative chronotropic effect.
• Class I antiarrhythmics (e.g., quinidine): increased risk of conduction disturbances.
• MAO inhibitors: potential for severe hypertension.

Moderate Interactions (Monitor Closely)

• NSAIDs: may blunt antihypertensive effect.
• Diuretics: risk of electrolyte imbalance and excessive blood pressure drop.
• Antidiabetic agents: may mask hypoglycaemia symptoms.
• ACE inhibitors or ARBs: monitor for additive blood pressure reduction.
• Digoxin: increased risk of bradycardia.