Note that inhaling lactose might elicit responses differently than 
eating it. I tend to think the latter could be more risky. No proof, though.

Also note that each form of a medication can be formulated 
differently. Those of us who have trouble with the lactose in the 10 
mg Singular tablets (adult strength) can change to 2- 5mg children's 
chewables, which (currently) are not formulated with lactose.

Mark