Used best choice 12 hour original nasal spray with the active ingredient Oxymetazoline Hydrochloride. Have used other manufacturers Oxymetazoline in past with NO adverse reaction.Immediately felt like a had inhaled an acid type liquid-(like lemon juice burning sensation) Within 10 seconds of use, I had severe burning and pain felt in my sinuses. My eyes started watering and became bloodshot and swollen. This continued for approximately two hours until I fell asleep. Woke up with severely blood shot and swollen eyes, still tearing and still was in pain 5 hours later. I even called poison control because it was so uncomfortable and I thought I had a reaction of some type. It is now 18 hours later still with severe sinus pain, bloodshot eyes and clear drainage from my nose with frequent sneezing. I will be contacting company in am. Saw one other report from Hattiesburg, Mississippi (50 miles from me) so this may be a regional issue. DO NOT USE BESTCHOICE NASAL SPRAY!!!