i see. so what doses are you currently taking? don't be shy, who really listens to the back of the packet for instructions of use eh. if you are taking a lot more than that, then i think that vicodin could be a good alternative. it will also stop the chances of liver toxicity from the apap in the co-codamols.
where do you live? in the states?
have you been going to regular physiotherapy sessions? they really do help out a lot.
again as stated, vicodin is also a potent narcotic and carries a higher risk of addiction than codeine does. it may also make you feel more drowsy than codeine, and climbing masts under the influence of a relatively powerful opiate may not be the best of ideas either.
i really suggest that you head to your doctor to discuss alternate medications for your back pain. i think to just jump to vicodin without his approval would be a little reckless and unwise.