Monamine Oxidase Inhibitors (MAOI). The enzyme monoamine oxidase
inactivates norepinephrine, dopamine, epinephrine, and serotonin. By inhibiting
monoamine oxidase, the levels of these neurotransmitters rise. Examples of
these drugs includes isocarboxazid (Marplan), phenelzine sulfate (Nardil), and
tranycypromine sulfate (Parnate).
A list of drugs utilized in the treatment of depression is provided in the
Appendix. Detailed tables show doses, recommendations, expectations, side
effects, contraindications, and more; available on the book’s Web site (see URL
in Appendix).
Summary
There are many medications that either interfere with impulses transmitted
over the neural pathways or stimulate those impulses. Medications that interfere
with impulses are called inhibitors and usually compete with neurotransmitters
for receptor sites. That is, the medication gets to the receptor site before the
neurotransmitters blocking the neurotransmitters from delivering the impulse
to the receptor site. Medications that cause an impulse to be generated are
called stimulants.
There are four major groups of medications that stimulate the central
nervous system. These are amphetamines, caffeine, analeptics, and anorexiants.
Amphetamines stimulate the cerebral cortex of the brain. Caffeine also stimu-
lates the cerebral cortex and stimulates respiration by acting on the brain stem
and medulla. Analeptics have a similar effect on the brain stem and medulla
as caffeine. Anorexiants inhibit appetite by stimulating the cerebral cortex and
the hypothalamus.
There are seven broad classifications of medications that depress the central
nervous system. These are sedative-hypnotics, general and local anesthetics, anal-
gesics, narcotic analgesics, anticonvulsants, antipsychotics, and antidepressants.
Sedative-hypnotics diminish the patient’s physical and mental responses
without affecting the patient’s consciousness. General anesthetics cause a loss of
consciousness and relieve pain. Local anesthetics block pain at the site where the
medication is administered without affecting the patient’s consciousness.
Analgesics are drugs that reduce pain such aspirin, acetaminophen, and
ibuprofen. Narcotic analgesics are drugs that reduce pain and produce a state of
stupor or drowsiness by blocking the transmission of pain signals in the brain.
CHAPTER 15 Nervous System Drugs^301