I am a typ 1 diabetic for 66 years and keep my glucose in fairly good control using the Medtronic pump....my pain management recently put me on the fentayl patch 25 mcg/hr.. My fasting glucose was 526! (I removed the patch.) w/additional insulin and my acupuncturist,) My readings are going down I have never been that high in the 66 yrs I ve had diabetes.. . The doctor said it will not cause any problems...with my diabetics.