This way, the pain medicine keeps a steady amount in the blood at all times. The pain never gets a chance to become really bad by getting ahead of the child. This is called tolerance. Tolerance means that the body has become used to the medicine and in order to stop the pain, the amount of medicine needs to be increased. This is not the same as being addicted.
Some pain medicines have side effects.
Most of them go away soon. Others can be treated so that the pain medicine can still be given. So we do not want to give them shots for pain. If a child has a lot of pain all the time we can give medicine through a special IV or with a medicine patch. This allows the child to get medicine all the time and avoid having pain.