I've been taking 2mg/day of sub strips for 2 weeks. Doc gave me low mg of Norco today. My last sub was yesterday am about 9am. How long do I need to wait to take opiates? Doc gave them to me for back pain and the subs were from a friend to help with my pain but after a few days I didn't feel the sub and went to 2mg/day. I just don't want to get sick or waste them. I've heard some say wait 36-48 hrs but I'm in pain now and need something to take and do not want to keep takings subs - I've heard the w/d are horrible!! Help ?