Childhood evaluation of salmeterol tolerance--a double-blind randomized controlled trial

Area of Science:

• Pediatric Pulmonology
• Asthma Therapeutics
• Pharmacology

Background:

• Long-acting beta(2)-agonists (LABA) are frequently prescribed for pediatric asthma management.
• Adult studies indicate potential tachyphylaxis to LABA's protective effects, but pediatric data are lacking.
• This study investigates tachyphylaxis in school-aged children with persistent asthma symptoms despite inhaled corticosteroid use.

Purpose of the Study:

• To determine if long-acting beta(2)-agonists (LABA) exhibit tachyphylaxis in school-aged children with asthma.
• To assess the efficacy and safety of combined salmeterol/fluticasone versus fluticasone alone in pediatric asthma.

Main Methods:

• Randomized, double-blind study in symptomatic children on 400 mcg beclometasone equivalent daily.
• Participants received either fluticasone (100 mcg BD) or salmeterol/fluticasone (50/100 mcg BD) for 8 weeks after a 4-week run-in.
• Evaluations included spirometry, cold air challenge, and salbutamol reversibility testing at baseline, 4, and 8 weeks.

Main Results:

• Salmeterol/fluticasone significantly improved baseline FEV1 (% predicted) compared to fluticasone alone.
• No significant additional bronchoprotection was observed with salmeterol/fluticasone compared to fluticasone alone.
• Significant attenuation of acute salbutamol response was noted in the salmeterol/fluticasone group after 8 weeks.

Conclusions:

• Combined salmeterol/fluticasone therapy enhances baseline lung function in pediatric asthma.
• Evidence suggests a potential tachyphylaxis to LABA's bronchodilator response in children.
• The observed reduction in salbutamol response may be partly due to improved baseline lung function.