My son is taking 500mg depakote 2 times a day. we want to taper off this med which causes him to have a lot of constipation and aggression.

Discuss w/ physician: Tapering such a medication should be under the guidance of the prescribing physician. Depakote is often prescribed by neurologists and psychiatrists for different conditions. You should discuss the symptoms with the prescribing neurologist or psychiatrist before making any changes because there may be other reasons. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682412.html

Consult your doctor: Talk to the prescribing doctor about your concerns, if there should be a med switch, or if it is safe/advisable to taper the medicine. I would suggest that it isn't the most responsible of decisions to make changes to this med based on anonymous internet advice. If you don't have a relationship with the doctor that prescribed the medication that you would describe as trusting, find a new doctor.

Why does he take: You do not say why he takes Depakote - seizures, mood disorder, migraine? If he has an onging condition, it may be good to start an alternative before discontinuing the Depakote. Speak to your doctor about this.