It probably will be a good idea to keep him in his crate so he doesn't move around too much at first anyway. As long as you monitor the incision, he should be okay by himself. Have you thought abotu running home over lunch to check on him, or having someone else check in on him during the day?
I have never had a male need pain medication after neutering. But, you can ask your vet what he/she thinks. I've only gone through the process three times, and I know each time has been different. When we got our George neutered, he wanted to run and play as soon as we got home. I had to crate him for a day just so he'd take it easy!
