What to do with 5 yr old with ADHD on the weekends?

It really depends. Especially with children this young, we know stimulants can slow height growth and depress appetite--both related directly to total stimulant dose over time. If the child is in an environment where he or she is functioning reasonably well without stimulant (or on a lower dose), you could consider med holidays. If adhd sx interfere with daily activities, then medication on weekends makes sense.
Same as week day. It's a common belief that medication for adhd are needed only during school time, and many parents don't want their kids to take the meds during the weekend. I suggest that beside school problems, the children have social difficulties also, and need to learn to live life both at school and at home. So i recommend that they take it as long as they need it, in and out of school.
Depends. Are you asking if they should take their medications on the weekends? I think most physicians would say that in most circumstances the answer is yes. If they need the medication to function at their best then it makes sense to take it daily. Adhd doesn't just cause school problems. The symptoms can also cause problems in the family and with friends, especially if the child is really impulsive.
What do you mean? If you mean:"treat or not treat?", then yes, treat w/ meds & behav approaches the exact same way as wkdays. If you mean "how do you occupy the child?", be active, get out, enjoy the child's world-as much as is practical. & get whatever help you need. Having the child spend a couple hours w/ a competent teen can do wonders for you & child. If still unmanageable or you r still overwhelmed, get prof help.
What do u want to do. The important questions are, how are your weekends going? Are you and your child surviving them without driving each other bonkers? As stated by other physicians, stability and consistency are a must.The danger of constantly having to correct a child for poor behavior is worse than any possible benefit ( if any) derived from a drug holiday, .
Same ol' same ol' Adhd doesn't know it's a weekend. Biology doesn't stop cause we define cultural conventions. Unstructured times are the most trying for ahd kid. Weekends should emulate weekdays as much as possible in structure. Structure & regular routine is the most important treatment for adhd after stimuant medication. Weekends should be as similar to weekdays as possible.