Three out of five people living in my house have strep throat right now. Here's the conversation I had with the pharmacist while picking up my daughter's antibiotics.
Ph: For some reason, it says on here that your daughter is allergic to amoxicillin.
Me: That's because she is allergic to amoxicillin.
Ph: Oh. But this is a whole different class of drugs.
Me: Right. Because she is allergic to the penicillin class.
Ph: Oh. Then this is the right drug for her.
Ph: Well. Here you go then.