Vicodin (Hydrocodone) and Nucynta (Tapentadol) are quite different drugs. The former bonds primarily with the opioid receptors, whereas the latter does both that and works with a few other mechanisms, such as norepinephrine reuptake.
Since pain meds effect each of us quite differently, the transition may be very easy, or you may have some withdrawal. It could go either way. Also, some people find Nucynta to be a great drug as it has multiple mechanisms of action. My experience is that it did help with pain, but made me to drowsy to work.
Note that, 10-15mg of hydrocodone daily for 9 months is not a lot in either quantity or duration. That is roughly my daily dose, and I've been taking it for nearly 7 years. I periodically go on medication breaks, and do not experience any significant withdrawal -- a bit of stomach upset, but that's about it.
Hopefully, the transition will be smooth -- but if you have diarrhea or stomach pains, chills, or other signs of withdrawal, contact your PM. You might need to cross-taper (i.e. taking less hydrocodone and low doses of nucynta for a few days or even a few weeks). Again, we all vary so it may be simple as pie, or it may cause what will hopefully be no more than minor discomfort.
C4-T4 Scoliosis (disk degeneration, stenosis, narrowed neuroforamen, bone spurs), RT hip and SI joint damage from car accident. Also, pectus excavatum, supraventricular tacycardia and mitral valve prolapse syndrome.
Current meds: Ultram ER 300mg daily, breakthrough - hydrocodone 10-15mg, or oxycodone 5-7.5mg. .25-.5mg ativan as needed for sleep, Verapamil 240mg SR (for tachycardia). [/gray