I have been taking Indomethacin for about 6 yrs in order to help control my gout outbreaks.

I was recently pulled over by a police officer for not signaling a lane change. At that time I was asked to take and failed a breathalyzer test. I am a 40yr old male, 220lbs and had 3 Coors Light beers over a 4 hr period (and I do have the receipt from the restaurant to show this). I don't understand how I failed the breathalyzer.
Thank you for any help that you may be able to provide.