Yes, thank you. My husband has been taken tramadol an Vicodine (switching on and off) for RA prescribed by doctor and now when blood test are taken this drug does not show up in his blood when blood test are taken why is this happening? His doctor thinks he is selling his meds, not true. In the past Paul use to do drugs heavily but has been clean for 5 yrs. Paul thinks this narcotic is not showing up because he may be high tolerance from all the past years he was doing drugs. Can you help explain to us why his blood is not showing these drug?