Yes, there are a number of medicines which interfere with Imatinib mesylate, including paracetamol. Therefore, you should not self medicate while taking Imatinib mesylate. Other medicines which interfere with Imatinib mesylate include cyclosporin, dexamethasone (a steroid), warfarin, antiviral medicines which treat AIDS. Some medicines which treat bacterial infections, high cholesterol, high blood pressure, heart problems, and mental disorders and depression can also affect the working of Imatinib mesylate. Consult your doctor before taking any medicine, and inform him that you are on Imatinib mesylate therapy.