I've been taking methadone 5mg 3x per day for the past 8 months and it works great for my pain. I was literally pain free until 2 days ago when suddenly, my pain is back full force. 3 days ago I was put on Doxycycline for Pneumonia. I don't see any interactions that would cause the methadone to stop working and my doctor checked for interactions before prescribing the Doxycyline. Has this happened to anyone else?