I'm not aware of ANY opioids (i.e. Vicodin, Morphine, Fentanyl, Dilaudid, Opana, etc etc) causing tremors of any kind... There are some meds (several antipsychotics and, perhaps, SSRIs) that DO cause tremors (the likelihood of getting them increases with dosage and duration of intake) so if your doctor has you on one of those as an adjunct to opiate therapy, they *might* be causing your shakes. However, this is something you should address--preferably asap--with your doctor. Best wishes.