Here are some quick resources you or your doctor might need.
Many medications are listed as “not safe” but without details of why, side effects, contraindications, or the effects when combined with other medications. These types of warnings are often just general liability statements. For ACTUAL risks and ACCURATE information regarding a medication, please search the LACTMED database. If this is not enough information, please contact the Infant Risk Center/Dr Thomas Hale mentioned below. Dr Hale also has a downloadable app for his books.
For information specifically regarding the use of isotopes for radiology and/or treatment: http://kellymom.com/bf/can-i-breastfeed/illness-surgery/radioisotopes/
The Infant Risk Center is a national research facility for breastfeeding. If your provider has questions about medications or you need more information, please contact them.