Adrenoceptor agonists (Sympathomimetics)
The selective beta2 agonists (selective beta2-adrenoceptor agonists, selective beta2 stimulants) such as salbutamol or terbutaline are the safest and most effective short-acting beta2 agonists for asthma. Less selective beta2 agonists such as orciprenaline should be avoided whenever possible. Adrenaline (epinephrine) (which has both alpha- and beta-adrenoceptor agonist properties) is used in the emergency management of allergic and anaphylactic reactions and in the management of croup.
Salbutamol:
Indications: used to treat asthma, chronic bronchitis, emphysema and to prevent exercise-related asthma.
Contraindications: contraindicated in patients with a history of hypersensitivity to albuterol or any of its components.
Dose and Administration:
By mouth, 4 mg (elderly and sensitive patients initially 2 mg) 3–4 times daily; max. single dose 8 mg; child under 2 years 100 micrograms/kg 4 times daily [unlicensed]; 2–6 years 1–2 mg 3–4 times daily, 6–12 years 2 mg 3–4 times daily By intravenous infusion, initially 5 micrograms/minute, adjusted according to response and heart-rate usually in range 3–20 micrograms/minute, or more if necessary; child 1 month–18 years initially 1–5 micrograms/kg/minute, adjusted according to response and heart rate (doses above 2 micrograms/kg/minute in intensive care setting). By aerosol inhalation, 100–200 micrograms (1–2 puffs); for persistent symptoms up to 4 times daily (but see also Chronic Asthma table); child 100 micrograms (1 puff), increased to 200 micrograms (2 puffs) if necessary; for persistent symptoms up to 4 times daily. Prophylaxis in exercise-induced bronchospasm, 200 micrograms (2 puffs); child 100 micrograms (1 puff), increased to 200 micrograms (2 puffs) if necessary. By inhalation of nebulised solution, chronic bronchospasm unresponsive to conventional therapy and severe acute asthma, adult and child over 18 months 2.5–5 mg, repeated up to 4 times daily; more frequently in severe cases; max. 40 mg daily; child under 18 months, [unlicensed] (transient hypoxaemia may occur—consider supplemental oxygen), 2.5 mg up to 4 times daily or more frequently in severe cases
Terbutalin:
Indications: asthma and other conditions associated with reversible airways obstruction.
Contraindications: Chronic Coronary Insufficiency, Conduction Disorder of the Heart, Hypertension.
Dose and Administration: By mouth, initially 2.5 mg 3 times daily for 1–2 weeks, then up to 5 mg 3 times daily; child 1 month–7 years 75 micrograms/kg 3 times daily; 7–15 years 2.5 mg 2–3 times daily.
Formoterol:
Indications: reversible airways obstruction (including nocturnal asthma and prevention of exercise-induced bronchospasm) in patients requiring long-term regular bronchodilator therapy, chronic obstructive pulmonary disease.
Contraindications: Acutely Deteriorating Asthma, Status Asthmaticus, Chronic Coronary Insufficiency, Conduction Disorder of the Heart, Hypokalemia, Seizure Disorder, Thyrotoxicosis.
Dose and Administration: asthma, adult and child over 5 years, 12 micrograms twice daily, increased to 24 micrograms twice daily in more severe airways obstruction. Chronic obstructive pulmonary disease, 12 micrograms twice daily.
Antimuscarinic bronchodilators
Ipratropium:
Indications: reversible airways obstruction, particularly in chronic obstructive pulmonary disease; rhinitis.
Contraindications: Benign Prostatic Hypertrophy, Bladder Outflow Obstruction, Narrow Angle Glaucoma, Ocular Hypertension, And Urinary Retention.
Dose and Administration: By inhalation of nebulised solution, reversible airways obstruction in chronic obstructive pulmonary disease, 250– 500 micrograms 3–4 times daily. Acute bronchospasm, 500 micrograms repeated as necessary; child under 5 years 125–250 micrograms, max. 1 mg daily; 6–12 years 250 micrograms, max. 1 mg daily.
Tiotropium:
Indications: maintenance treatment of chronic obstructive pulmonary disease
Contraindications: Acute Asthma Attack, Increased Cardiovascular Event Risk, Narrow Angle Glaucoma. Benign Prostatic Hypertrophy, Bladder Outflow Obstruction, Renal Disease with Moderate to Severe Function Impairment.
Dose and Administration: By inhalation of powder, adult over 18 years, 18 micrograms once daily.
Theophyllines
Theophylline:
Indications: Bronchial Asthma, Chronic Obstructive Asthma, Chronic Obstructive Pulmonary Disease with Bronchospasms, and COPD Associated with Chronic Bronchitis, Pulmonary Emphysema.
Contraindications: Angina, Myocardial Infarction, Peptic Ulcer, Seizure Disorder, and Tachyarrhythmia.
Dose and Administration:
Adult Min/Max Dose: 6.0mg/kg/24.0mg/kg
Pediatric Min/Max Dose: 2.0mg/kg/24.0mg/kg.
Plasma-theophylline concentration for optimum response 10–20 mg/litre (55–110 micromol/litre); 4–6 hours after a dose and at least 5 days after starting treatment; narrow margin between therapeutic and toxic dose
Aminophylline:
Indications: Asthma Prevention, Bronchial Asthma, Bronchitis, Bronchospastic Pulmonary Disease, Chronic Obstructive Asthma, Nocturnal Asthma, Pulmonary Disease, Pulmonary Emphysema, and Status Asthmaticus.
Contraindications: Angina, Myocardial Infarction, Peptic Ulcer, Seizure Disorder, and Tachyarrhythmia
Dose and Administration: Acute severe asthma or acute exacerbation of chronic obstructive pulmonary disease not previously treated with theophylline, by slow intravenous injection over at least 20 minutes (with close monitoring), 250–500 mg (5 mg/kg), then see below; child 5 mg/kg. Acute severe asthma or acute exacerbation of chronic obstructive pulmonary disease, by intravenous infusion (with close monitoring), 500 micrograms/kg/hour, adjusted according to plasma-theophylline concentration; child 6 months–9 years 1 mg/kg/hour, 10–16 years 800 micrograms/kg/hour, adjusted according to plasma-theophylline concentration.
