<span>This person is considered to be impaired. Impairment means that natural or normal functions are no longer working correctly, which then plays a role in what the person is able or not able to do. Since this person's immune system no longer functions, they are considered to be impaired.</span>
A drug is a chemical substance used to treat, prevent, or diagnose a disease or alter one or more functions of the body. Antibiotics, Analgesics, and antihistamine are all not able to do all of the following.