Buterol

• Approved Indications:
• Maintenance treatment of bronchial asthma for prevention of bronchospasm.
• Management of chronic obstructive pulmonary disease (COPD) to relieve airway obstruction.
• Prevention of exercise-induced bronchospasm in patients requiring long-acting bronchodilation.
• Off-label Uses:
• Adjunct therapy for other obstructive airway diseases where long-term bronchodilation is beneficial.

• Route: Oral administration (tablet).
• Adults:
• Initial dose: 10 mg once daily, preferably in the morning.
• Dose may be increased to 20 mg once daily based on clinical response and tolerability.
• Elderly:
• Same as adult dose, with careful monitoring for cardiovascular side effects.
• Pediatrics:
• Safety and efficacy not established; use only under specialist supervision.
• Renal Impairment:
• Use caution; dose adjustment may be necessary in moderate to severe impairment.
• Hepatic Impairment:
• Use with caution; no specific dosage adjustment guidelines.
• Administration Notes:
• Taken once daily, preferably at the same time each day.
• Not intended for relief of acute bronchospasm.

Bambuterol Hydrochloride is a prodrug converted in the body to terbutaline, a selective β2-adrenergic receptor agonist. Activation of β2 receptors in bronchial smooth muscle increases intracellular cyclic AMP, leading to relaxation of airway smooth muscle and bronchodilation. This action reduces airway resistance and improves airflow. The prodrug formulation allows for prolonged action, supporting once-daily dosing.

• Absorption: Well absorbed from the gastrointestinal tract after oral administration.
• Bioavailability: Approximately 20%, with conversion to active metabolite terbutaline increasing systemic exposure.
• Distribution: Moderate plasma protein binding.
• Metabolism: Hydrolyzed by plasma cholinesterases to active terbutaline.
• Elimination Half-life: Approximately 16 hours, supporting once-daily dosing.
• Excretion: Primarily renal excretion of unchanged drug and metabolites.

• Pregnancy:
• No adequate human studies; animal data do not indicate teratogenicity. Use only if benefits justify potential risk.
• Lactation:
• Terbutaline is excreted in breast milk in small amounts; caution advised when administered to nursing mothers.

• Bronchodilator
• Long-acting β2-adrenergic receptor agonist (LABA) prodrug

• Hypersensitivity to bambuterol, terbutaline, or formulation excipients.
• Severe cardiac arrhythmias.
• Untreated thyrotoxicosis.
• Concurrent use of non-selective beta-blockers.

• Use with caution in patients with cardiovascular disease (hypertension, ischemic heart disease).
• Risk of hypokalemia, especially when combined with diuretics or corticosteroids.
• Not for acute bronchospasm relief; risk of paradoxical bronchospasm exists.
• Caution in diabetics due to possible hyperglycemia.
• Monitor for signs of tolerance or exacerbation of symptoms.

• Common: Tremor, headache, palpitations, nervousness, muscle cramps.
• Cardiovascular: Tachycardia, arrhythmias (rare).
• Gastrointestinal: Nausea, dry mouth.
• Rare but serious: Paradoxical bronchospasm, hypersensitivity reactions including rash and angioedema.

• Beta-blockers may reduce efficacy.
• Diuretics may increase risk of hypokalemia.
• MAO inhibitors and tricyclic antidepressants may potentiate cardiovascular effects.
• Minimal CYP450 involvement, reducing interaction potential.

• Current guidelines recommend use of LABAs like bambuterol mainly in COPD and as add-on therapy in asthma with corticosteroids.
• Emphasis on cardiovascular monitoring in elderly and patients with comorbidities.
• No significant recent changes in dosing or safety.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep container tightly closed.
• Do not freeze.
• Store out of reach of children.