Central Nervous System Drugs
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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.
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