The nervous system's, the central nervous system (CNS) and the peripheral nervous system (PNS) are still functional during a pharmacological induced coma but the person is sedated. Drug induced sedation slows down all body systems including the brain. The medications used to accomplish this state are sedating. Some are also paralyzing, they prevent movement. Examples of medications used to sedate someone are similar to those used in the operating room to achieve the various levels of anesthesia. Two common medications used for inducing coma and deep anesthesia are Midazolam and Propafol. These medications are nervous system depressants. Midazolam also has amnesic effects so when the patient "wakes up" they don't remember the ordeal that they have been through.
A drug induced coma is initiated with the help of drugs like barbiturates like pentobarbital or sedatives like propofol. During the coma there is no brain wave activity which can be seen with the help of an EEG which is completely flat. The patient becomes completely unresponsive to all external stimuli like light, sound, pain, etc. A drug induced coma is used to place the brain in a state of rest and close down as much activity in the body as possible. This is used in cases where there has been a lot of injury to the brain or any other part of the body and it is essential that all the resources of the patient’s body be used for healing the damage.
During the coma the doctor needs to monitor the patient closely to deal with problems that are due to immobility, which include pneumonia, formation of blood clots, muscle paralysis and weakness. It is also essential to maintain the nutritional status of the patient so that they are normal when they are brought out from the state of coma.