I want to make a clarification about hydrocodone/Vicodin. It is true that there are classic allergy symptoms that are experienced in most types of allergies. These are symptoms like hives, swelling, difficulty breathing, itching, etc. But some medications can also cause less common allergy symptoms like gastrointestinal issues, pain and depression. Vicodin is one of them.
I am allergic to Vicodin and the only allergy symptoms I had were depression, confusion and frequent urination. I thought that these were side effects but my doctor confirmed that I am having a reaction to Vicodin and had me quit immediately. I was given an IV serum to help the drug leave my system.
So if there are odd symptoms after taking Vicodin, it's a good idea to call the doctor about it. Of course symptoms like swelling and difficult breathing require an immediate visit to the emergency room.