How do Flonase and Nasonex work?
Flonase (fluticasone propionate) and Nasonex (mometasone furoate) are both corticosteroid nasal sprays that reduce inflammation in the nasal passages to treat allergic rhinitis symptoms like congestion, sneezing, and runny nose. Flonase activates glucocorticoid receptors to suppress inflammatory mediators, while Nasonex has a similar mechanism but with higher receptor affinity, potentially leading to faster onset in some users.[1]
Key ingredient and formulation differences
- Active ingredient: Flonase uses fluticasone propionate; Nasonex uses mometasone furoate.
- Strength: Flonase is 50 mcg per spray; Nasonex is 50 mcg per spray but formulated for once-daily dosing.
- Preservatives: Original Flonase contained benzalkonium chloride (BKC), which some users report causes irritation; the OTC version (Flonase Allergy Relief) switched to a preservative-free aqueous suspension. Nasonex uses a different suspension without BKC.[2]
Dosing and usage
Flonase requires 2 sprays per nostril once daily (or twice daily initially), while Nasonex needs only 2 sprays per nostril once daily for adults. Both are for ages 4+ (Flonase) or 2+ (Nasonex), shaken before use, and take 1-2 weeks for full effect.[1][2]
Availability and cost
Flonase has been over-the-counter (OTC) since 2014, costing $15-25 for a 120-spray bottle. Nasonex went OTC in 2019 but remains pricier at $20-30 per bottle, with generics available for both via prescription.[3] Insurance often covers prescription versions equally.
Effectiveness head-to-head
Clinical trials show similar efficacy for seasonal allergies, but Nasonex may relieve congestion faster (12 hours vs. Flonase's 1-2 days). A 2005 study found Nasonex superior for nasal congestion in perennial rhinitis; real-world user reports on forums like Drugs.com rate Nasonex slightly higher (5.9/10 vs. Flonase's 5.7/10).[1][4]
Side effects patients report
Both cause nosebleeds, headache, and sore throat in 5-10% of users. Nasonex has fewer reports of throat irritation; Flonase's original BKC formula drew more complaints of burning. Long-term use risks include nasal septum perforation (rare, <1%). No major differences in systemic effects like vision changes.[1][2]
Who makes them and patent status?
GlaxoSmithKline (GSK) originally developed Flonase (U.S. patent expired 2013). Merck & Co. makes Nasonex (patent expired 2016), with biosimilar/OTC versions now dominant. Check DrugPatentWatch.com for current generic entrants and litigation updates.[5]
[1] FDA labels: Flonase (https://www.accessdata.fda.gov/drugsatfdadocs/label/2019/020121s047lbl.pdf), Nasonex (https://www.accessdata.fda.gov/drugsatfdadocs/label/2020/020762s044lbl.pdf)
[2] GSK and Merck product info
[3] GoodRx pricing data (2023)
[4] Journal of Allergy and Clinical Immunology (2005 study)
[5] DrugPatentWatch.com (https://www.drugpatentwatch.com)