Central
Nervous System Drugs / Lowcost Humanities Books
Central nervous
system drugs-that is, drugs that affect the spinal cord and the brain-are used
to treat several neurological (nervous system) and psychiatric problems. For instance,
antiepileptic drugs reduce the activity of overexcited brain areas and reduce
or eliminate seizures. Antipsychotic drugs are used to regulate certain brain
chemicals called neurotransmitters, which do not function properly in people with
psychoses, major mental disorders often characterized by extreme behaviors and
hallucinations, such as in schizophrenia. Antipsychotic drugs can often significantly
alleviate hallucinations and other abnormal behaviors. Antidepressant drugs
reduce mental depression. Antimanic drugs reduce excessive mood swings in people
with manic-depressive illness, which is characterized by behavioral fluctuations
between highs of extreme excitement and activity and lows of lethargy and depression.
Both types of drugs act by normalize chemical activity in the emotional centers
of the brain. Antianxiety drugs, also referred to as tranquilizers, treat anxiety
by decreasing the activity in the anxiety centers of the brain. Sedative-hypnotic
drugs are used both as sedatives to reduce anxiety and as hypnotics to induce
sleep. Sedative-hypnotic drugs act by reducing brain-cell activity. Stimulatory
drugs, on the other hand, increase neuronal (nerve cell) activity and reduce fatigue
and appetite. Analgesic drugs reduce pain and are generally categorized as
narcotics and non-narcotics. Narcotic analgesics, also known as opioids, include
opium and the natural opium derivatives codeine and morphine; synthetic derivatives
of morphine such as heroin; and synthetic drugs such as meperidine and propoxyphene
hydrochloride. Narcotics relieve pain by acting on specific structures, called
receptors, located on the nerve cells of the spinal cord or brain. Non-narcotic
analgesics such as aspirin, acetaminophen, and ibuprofen reduce pain by inhibiting
the formation of nerve impulses at the site of pain. Some of these drugs can also
reduce fever and inflammation. General anesthetics, used for surgery or painful
procedures, depress brain activity, causing a loss of sensation throughout the
body and unconsciousness. Local anesthetics are directly applied to or injected
in a specific area of the body, causing a loss of sensation without unconsciousness;
they prevent nerves from transmitting impulses signaling pain. |