First talk with the doctor prescribing your child's meds to see if adjustments can be made to the regimen. Children who take long-acting medications to get through the school day are sometimes also prescribed a short-acting drug to help later in the evening.
Try to keep your evenings -- when your child is most vulnerable to unraveling as his medication wears off -- relaxed. Avoid overstimulating him or making unnecessary demands, and stick to a set routine as often as possible (like homework, dinner, bath, brush teeth, read a story, bedtime). Here are a few more strategies to help keep your child calm:
• Kids with ADHD seek stimulation, so avoid explosive or emotional responses when your child misbehaves. You don't want to inadvertently reward bad behavior with a highly charged reaction.
• If you must discipline your child (like for hitting a sibling) start by first acknowledging his feelings. Say, "I can see why you would be frustrated," and then discuss why his actions were inappropriate.
• Avoid asking "why" questions, like "why did you do that?" Instead use "what" queries such as, "what are you supposed to be doing right now?" and "what would you like to see happen?"
• If your child is on the verge of a meltdown, remind him to use some of the self-soothing techniques he was probably taught in therapy, like deep breathing and counting slowly.