To answer your question, you can buy neosporin that has an added pain reliever in it. However, I would not want to use something that has pain relieving capabilities meant for humans on a reptile. The dosage on the pain reliever might be too much for the snake.

Applying a little neosporin on some of the dry scales should be ok. If that makes you uncomfortable putting something intended for humans on a snake, you can always get some Shed ease.