My brother is ADHD inattentive, I am really scared about medication?

Maybe not only way. You don't say how old your brother is. Inattentive adhd can be quite responsive sometimes to even low doses of stimulants; however, if it is just attention and focus, behavioral and structural approaches also have been shown to be quite helpful. External structure from parents and teachers may be as effective as medications. But, like meds, they only work when appllied consistently.