Mucinex nasal spray is used to temporarily relieve congestion due to cold, hay fever, upper respiratory allergies, according to Drugs.com. It promotes nasal and sinus drainage, and aids in clearing nasal passages and shrinking swollen membranes.
Mucinex nasal spray is a nasal decongestant with the active ingredient oxymetazoline hydrochloride, notes Drugs.com. It requires two to three sprays in each nostril at a maximum of every 10 to 12 hours, not to exceed more than two doses over a 24-hour period. Mucinex nasal spray should not be used for longer than three days, as overuse can cause congestion to become worse or recur.