Final answer:
Aspirin should not be given to a person 18 years and younger due to the risk of developing Reye's Syndrome.
Step-by-step explanation:
The drug that should not be given to a person 18 years and younger is aspirin.
Reye's Syndrome, a condition that can occur in young people who take aspirin when they have a viral infection, causes swelling of the brain and can be fatal. It is recommended to avoid taking aspirin when you have a viral infection, as products like cold medicines often contain aspirin. It is important to read labels carefully when taking any medicines to prevent Reye's Syndrome.