Asmatol

• Bronchospasm:
  Treatment and prevention of bronchospasm in reversible obstructive airway diseases such as:
• Asthma (mild, moderate, and severe)
• Chronic Obstructive Pulmonary Disease (COPD)
• Chronic bronchitis
• Emphysema
• Exercise-Induced Bronchospasm:
  Prevention of bronchospasm caused by physical exertion.
• Off-label Uses:
• Temporary management of hyperkalemia by shifting potassium intracellularly.
• Tocolytic therapy in premature labor (used with caution and under specialist supervision).

• Adults and Adolescents (≥12 years):
• Inhalation (Metered-Dose Inhaler, MDI):
  100 to 200 micrograms (mcg) (1 to 2 inhalations) every 4 to 6 hours as needed.
  Maximum daily dose usually should not exceed 800 mcg.
• Nebulizer Solution:
  2.5 mg administered 3 to 4 times daily. Dose may be increased based on clinical response.
• Oral Tablets or Syrup:
  2 to 4 mg three to four times daily.
• Children (6 to 11 years):
• Inhalation:
  100 mcg (1 inhalation) every 4 to 6 hours as needed.
• Nebulizer:
  1.25 mg 3 to 4 times daily.
• Oral:
  2 mg three times daily.
• Children (<6 years):
• Nebulized solution dosing generally 0.15 mg/kg per dose every 4 to 6 hours, under medical supervision.
• Elderly:
  No dosage adjustment required; monitor for cardiovascular side effects.
• Renal or Hepatic Impairment:
  No specific dose adjustments recommended but exercise caution.
• Administration Notes:
• Preferred route is inhalation for rapid bronchodilation and reduced systemic side effects.
• Oral forms may be used when inhalation is not feasible.
• Tablets and inhalers should be taken as prescribed and not exceeded.

Salbutamol is a selective β2-adrenergic receptor agonist that stimulates β2 receptors on bronchial smooth muscle cells. Activation of these receptors increases intracellular cyclic adenosine monophosphate (cAMP) levels via adenylate cyclase activation, resulting in relaxation of bronchial smooth muscle and subsequent bronchodilation. This action rapidly relieves bronchospasm and improves airflow. Salbutamol’s relative selectivity for β2 receptors minimizes cardiac β1 receptor stimulation, reducing cardiovascular side effects compared to non-selective adrenergic agonists.

• Absorption:
  Rapidly absorbed from the respiratory tract after inhalation; oral bioavailability is approximately 50% due to first-pass hepatic metabolism.
• Distribution:
  Widely distributed throughout the body, including crossing the placenta and present in breast milk in low concentrations.
• Metabolism:
  Primarily metabolized in the liver by sulfation to inactive metabolites.
• Excretion:
  Mainly eliminated via the kidneys as metabolites and unchanged drug.
• Onset of Action:
  Inhalation: 5 minutes.
  Oral: Approximately 30 minutes.
• Duration of Action:
  Typically 4 to 6 hours.
• Half-life:
  Approximately 3.8 to 6 hours.

• Pregnancy:
  Classified as FDA Pregnancy Category C. Animal studies have shown adverse effects at doses higher than therapeutic levels. No adequate controlled studies in pregnant women are available. Use only if the potential benefit justifies the risk to the fetus.
• Lactation:
  Salbutamol is excreted in human breast milk in small amounts. Caution is advised; monitor nursing infants for adverse effects.
• Recommendation:
  Use during pregnancy and breastfeeding only under medical supervision.

• Primary Therapeutic Class:
  Short-acting β2-adrenergic receptor agonist (SABA).
• Subclass:
  Bronchodilator and sympathomimetic agent.

• Known hypersensitivity to salbutamol or any formulation components.
• Use with caution or contraindicated in patients with significant cardiovascular disorders (e.g., tachyarrhythmias).
• Concomitant use with non-selective monoamine oxidase inhibitors (MAOIs) or tricyclic antidepressants without medical supervision due to increased cardiovascular risk.

• Cardiovascular Effects:
  May cause tachycardia, palpitations, arrhythmias; use cautiously in patients with cardiac disease or hypertension.
• Paradoxical Bronchospasm:
  Rare but potentially life-threatening; discontinue salbutamol immediately if this occurs.
• Hypokalemia:
  Can lower serum potassium levels, especially in high doses or with concomitant diuretics.
• Tolerance Development:
  Excessive or frequent use may lead to reduced bronchodilator effectiveness.
• High-Risk Populations:
  Elderly, patients with hyperthyroidism, diabetes mellitus, and seizure disorders require careful monitoring.
• Monitoring:
  Regular assessment of respiratory function and cardiovascular status is recommended during treatment.

• Common Side Effects:
• Tremor (especially hand tremors)
• Nervousness or anxiety
• Headache
• Tachycardia or palpitations
• Muscle cramps
• Throat irritation (with inhaled use)
• Serious/Rare Side Effects:
• Paradoxical bronchospasm
• Hypokalemia
• Cardiac arrhythmias
• Allergic reactions (rash, angioedema, urticaria)
• Onset:
  Side effects typically occur shortly after administration.

• Beta-blockers:
  May antagonize the bronchodilatory effects of salbutamol.
• MAO Inhibitors and Tricyclic Antidepressants:
  Potentially increase cardiovascular side effects; avoid or monitor closely.
• Diuretics:
  Risk of hypokalemia is increased with concomitant use.
• Digoxin:
  Salbutamol may reduce serum digoxin concentrations.
• Other Sympathomimetics:
  Additive cardiovascular effects may occur.
• Food and Alcohol:
  No significant interactions, but alcohol may enhance CNS side effects.

• Current asthma and COPD management guidelines (e.g., GINA, GOLD) continue to recommend salbutamol as a first-line rescue bronchodilator.
• No significant changes in dosing or safety profile in recent years.
• Emphasis on avoiding overuse to prevent tolerance and side effects.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture, heat, and direct light.
• Keep inhalers and nebulizer solutions tightly closed when not in use.
• Do not freeze.
• Keep out of reach of children.
• Follow manufacturer instructions for opened nebulizer solutions.