Iodinated contrast agents are on the list of drugs to be used with caution in patients with MG. See p. 20 of this file:
http://www.myasthenia.org/LinkClick....JuFvZPPq2vg%3D
On the other hand, I found this:
http://www.ncbi.nlm.nih.gov/pubmed/3614668
Here's another list:
http://dig.pharm.uic.edu/faq/myasthenia.aspx
Abby