Hello, Your medical and dental history would be helpful in determining if a drug has caused this condition. There are many reasons and it can signal a systemic change occuring to your body - hormonal, endocrine disorder, organ disfunction or damage, allergy, diet change, infection, tumor or cancer. I would suggest a blood test and physical evaluation as well as an updated dental exam. Clinical evaluation of the tongue would be helpful. Other conditions such as texture, color, coating on tongue may give some direction and help with a diagnosis. Trauma or habits can contribute. Does anything seem to affect the tongue? Any pain or sore spots? Thank you for your inquiry. I would be glad to expand my answer with additional details. I am glad to offer as much assistance as possible without seeing your condition.