Medolin (Salbutamol)

• Salbutamol is a short‑acting bronchodilator that acts on the β2‑adrenergic pathway to relieve airway obstruction.
• Asthma: provides rapid relief of bronchoconstriction, improving airflow and reducing wheezing.
• Chronic obstructive pulmonary disease (COPD): alleviates acute episodes of bronchospasm, enhancing breathing capacity.
• Bronchospasm (including exercise‑induced): quickly relaxes bronchial smooth muscle to restore normal ventilation.

• Salbutamol selectively stimulates β2‑adrenergic receptors on bronchial smooth‑muscle cells. Activation of these G‑protein‑coupled receptors increases intracellular cyclic AMP, which inhibits calcium influx and promotes relaxation of the airway smooth muscle. The resulting bronchodilation reduces airway resistance and improves ventilation, delivering rapid symptom relief in obstructive airway conditions. The effect is dose‑dependent and reversible within minutes, making it suitable for rescue therapy.

Oral salbutamol may be associated with a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Tremor: mild muscle shaking, often in the hands.
• Headache: transient headache episodes.
• Palpitations: sensation of rapid or irregular heartbeat.
• Nausea: mild gastrointestinal upset.
• Nervousness: feeling of anxiety or restlessness.
• Insomnia: difficulty falling or staying asleep.

Serious or Rare Side Effects

• Paradoxical bronchospasm: worsening airway constriction after dose.
• Severe tachycardia: markedly increased heart rate requiring medical attention.
• Hypokalemia: low blood potassium levels that may cause weakness.
• Cardiac arrhythmia: abnormal heart rhythm, potentially life‑threatening.
• Angina pectoris: chest pain due to reduced coronary blood flow.
• Anaphylactic reaction: severe allergic response with hives, swelling, or breathing difficulty.

When prescribing oral salbutamol, clinicians should consider several precautionary measures to ensure safe use.

• Cardiac monitoring: observe patients with known heart disease for tachycardia or arrhythmias.
• Caution in hypertension: avoid excessive doses in patients with high blood pressure.
• Electrolyte assessment: check potassium levels, especially if diuretics are used concurrently.
• Pregnancy and lactation: use only if the potential benefit outweighs the risk, after medical evaluation.
• Concomitant β‑blockers: anticipate reduced bronchodilator efficacy and possible bronchospasm.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Salbutamol can interact with other medicines, influencing its efficacy or safety profile.

Major Interactions (Avoid)

• Non‑selective β‑blockers: may block bronchodilation and precipitate bronchospasm.
• Monoamine oxidase inhibitors (MAOIs): increase risk of severe hypertension and tachyarrhythmia.
• Diuretics (especially loop): can exacerbate hypokalemia, heightening cardiac risk.

Moderate Interactions (Monitor Closely)

• Theophylline: additive stimulant effect on the cardiovascular system.
• Other β2‑agonists: may increase risk of tremor, tachycardia, and hypokalemia.
• Antihypertensive agents (e.g., ACE inhibitors): monitor blood pressure as salbutamol may reduce their effectiveness.
• Anticholinergic bronchodilators: assess combined respiratory effects.