it could be from a similar cause since codeine has a similar active ingredient to vicodin. vicodin has hydrocodone and acetomeniphen. codeine is simply codeine phosphate and isn't as strong but both are opiates. perhaps you have a sensitivity to them?
i have had a violent reaction to vicodin after surgery. would this explain my nausea after taking codeine? . the vicodin caused violent retching several years ago. i took the codeine-based cough suppressant last night and my nausea didn't happen until this morning.