Ooo the shots are fun. I'm giving mine the same antibiotic and have been for a bit. Honestly, if it makes you feel uncomfortable find another vet or call an emergency exotic pet vet.

The vet that I go to (an hour and a half drive) has two doctors who deal with reptiles. One who actually got her doctorate in reptile studies and the other one is almost that experienced. I called the emergency vet to double check how to give the shots right before I did. They can answer any general question.