Sorry if this is not what you are looking for, as we have not tried meds.
I have an 8-year-old who has serious anger-management issues, but we are making wonderful progress, so I feel compelled to share. She still has those blow-outs, but instead of hours-long, smashing stuff, hitting, etc., she is crying in her room for 5 minutes and then coming out with an apology.
We saw a therapist for a while, who did play therapy with DD. It was really helpful. Perhaps not for DD, but for me. The therapist really listened (without judgment!), and she had great advice. She was the one who convinced me that DD would not act like that if she could help it, that getting mad and/or punishing her would never help. Instead, building up her self-esteem has been crucial, along with teaching self-regulation skills. For that, we really liked What To Do When Your Temper Flares. This year, we are using the MindUP curriculum, and it is wonderful. I like that it teaches real information about the brain, which really helps DD understand why she has reactions and how to stop herself.