Preconditions

Patient

• Child of 2 years and above
• 3 weeks from last asthma exacerbation
• 3 weeks from last airway infection

Medication abstinence

• Short-acting beta-2 agonists: 8 hours
• Long-acting beta-2 agonists: 24 hours
• Leukotriene antagonists: 5 days
• Antihistamines: 48 hours