Answer
The benzalkonium chloride in Beconase Aqueous Nasal Spray (beclometasone) may cause bronchospasm and irritation or swelling inside the nose, especially with prolonged use.
Sources for this answer
- Beconase Aqueous Nasal SprayGlaxoSmithKline UK · emc · SmPC §4.4 Special warnings and precautions for use · Version 16Document updated
Sources checked