I have been on Concerta ER 54mg and went off for over a year. Now I'm restarting and still had a half bottle from a year ago that I brought to my appointment with my GP. He's not the one who prescribed it. I don't think he's comfortable prescribing it so he told me to just start that old bottle. I'm not comfortable going from zero to 54. I can't cut it in half as it is extended release. Or is there a safe way to cut a 54 in 4 equal pieces to start out?