I been off methadone for 5 days. starting suboxone maintance tomorrow. will the blocker in suboxone make me feel sick if methadone is still in me?

YES!!!: Unfortunately the half life of Methadone is extremely long so chances are it is not completely out of your system in 5 days depending on the last dose. The opiate blocker in Suboxone will kick off the rest of the methadone. But good for you on switching it will be way better in the long term!

Possibly: It depends on the dose of Methadone you were receiving prior to starting suboxone. If you were on 30 mgs per day or less, after five days off methadone, you might be okay especially if you start with a very low dose of Suboxone and increase it very gradually. The Methadone will still be in your system for a while, but a very low dose of Suboxone with a very gradual dosing increase could work fine.