Diastat is absorbed quickly from the rectum. Seizures may stop within 15 minutes of giving the medicine, but it will continue to work for much longer. The Diastat reaches a peak level in the bloodstream in about 1.5 hours, but can last almost 2 days.

  • Follow instructions from your doctor carefully on how often Diastat can be given.
  • Since it can last a long time in the body, a second dose should be given only if and when it's prescribed for continued seizures. 
  • Also make sure you know how often you can use this for cluster seizures - for example how many days between clusters can it be given and how many times a month can it be used.
  • Diastat is generally recommended to be used only once every 5 days or no more than 5 times a month. If you have clusters more often than this, talk to your health care professional about what to do.


  • Ask the doctor when a second dose should be given.
  • Diastat should not be used instead of your child's regular medicine - ask the doctor how often to use it.