Sure, you can work. Will you want to? Probably not.
I think the best job is doing lab work for other students if that is allowed at your school. I sometimes make $50 an hour if I get a couple cases at once to work on. A couple hours of lab work throughout the week can equal an entire week of delivering pizza in the evenings.
I'm a second year and have been working the same job since junior year of undergrad. I do the book-keeping for a dentist with a 3-clinic practice. and I do well in my classes.