Nasonex is an intranasal corticosteroid, or INS, with the active ingredient mometasone furoate monohydrate, which is not available over the counter, states Pharmacy Times. However, fluticasone proprionate, sold as Flonase Allergy Relief, and triamcinolone acetonide, sold as Nasacort, are available without a prescription.
Flonase works by blocking, among other messengers, histamine and prostaglandins, which are some of the main culprits causing the typical symptoms of allergies, explains RxList. These include a runny nose, nasal congestion and watery eyes. Nasacort, the other alternative to Nasonex, claims to provide the same benefits as Nasonex, with the added benefit of being available without a prescription. Oral medications that are available over-the-counter include Claritin and Zyrtec, both of which are non-sedating. The active ingredients are loratidine and cetirizine, respectively.
Intranasal corticosteroids were first approved by the FDA in 2013, notes Pharmacy Times. Mometasone furoate monohydrate, the ingredient in Nasonex, is used to prevent seasonal allergies, which are mediated by certain chemical messengers in the human body. A generic form of Nasonex was prevented by patent law until July 2014, explains Drugs.com.