My urologist orders a diunetic renogram with grf estimation. i have asthama, how can i avoid alergic reaction that may be caused by ranogram?

Are you allergic to: Lasix (furosemide)? That is the diuretic most commonly used in the us when performing a diuretic renogram. Also, is it a GFR nuclear renogram? If so, the radiopharmaceutical used is usually 99mtc-dtpa and I am not aware of patients being allergic to it. If iodinated contrast is to be used, low osmolar is most common, and asthmatics have no appreciable increased reaction risk ("allergy") to it.