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Chapter 4:
Prescription Drugs
Depressants
Perhaps the most
widely-used category of psychoactive drugs in the world today,
depressants are similar in their main actions, but different
in the way they trigger those actions.
The two main
types of depressants abused for their psychoactive effects are
sedative-hypnotics (or sleeping pills) and tranquilizers.
Sedative-Hypnotics
Examples:
Barbiturates:
pentobarbital (Nembutal®), secobarbital (Seconal®), amobarbital
(Amytal®). Non-barbiturates: glutethimide (Doriden®),
ethchlorvynol (Placidyl®), chloral hydrate.
Actions: Sedative-hypnotics slow
CNS functioning, causing drowsiness, sleep, and mild intoxication
(euphoria, reduced inhibitions, poor coordination, slurred speech,
impaired thinking and memory, increased aggressiveness) at moderate
doses.
Higher dosage
levels produce profound depressant effects and can dramatically
slow breathing.
Demographics: The past decade has
seen a decline in use, tied to new awareness of the hazards of
traditional sedative-hypnotics and increased use of less-toxic
substitutes. Methaqualone (Quaalude®), in particular, has
almost vanished as a drug problem in the United States, since
its manufacturer halted production in 1984.
Tolerance:
Rapid
development of tolerance is typical.
Potentiation:
Sedatives
intensify the effects of other depressants, raising risks of
overdose, coma, and death.
Overdose: Although tolerance builds
quickly, the overdose threshold stays relatively fixed, multiplying
risks of overdose for regular users.
Addiction:
Sedative-hypnotics
are highly addicting, producing physical and psychological dependence
following regular use for one or two months, or at doses above
recommended therapeutic levels.
Other problems
include suppression of rapid eye movement (REM, or dreaming)
sleep, associated with increased anxiety, irritability and morning-after
"hangovers" following use of barbiturates.
Medical Uses:
To induce
sleep, reduce anxiety, control epileptic seizures, and as an
aid in the diagnosis of psychiatric disorders.
Main Dangers: Immediate hazards arise
from faulty judgment and poor coordination and accidental overdose.
Long-term risks include dependence and life-threatening withdrawal
symptoms.
Withdrawal
Symptoms: Sedatives,
particularly barbiturates, produce a severe withdrawal syndrome
considered more dangerous and potentially life-threatening than
withdrawal from heroin. Symptoms include cramps, vomiting, shaking,
insomnia, delirium, and convulsions. Withdrawal should only be
attempted under medical supervision.
Signs of Use:
Alcohol-like
intoxication, including impulsiveness, increased aggression,
poor coordination, slurred speech.
Tranquilizers
Examples:
Minor
Tranquilizers [benzodiazepine type]: diazepam (Valium®),
alprazolam (Xanax®), chlordiazepoxide (Librium®), flurazepam
(Dalmane®), lorazepam (Ativan®); [non-benzodiazepine
type]: meprobamate (Miltown®). Major Tranquilizers: chlorpromazine
(Thorazine®), thioridazine (Mellaril®).
Actions: Minor tranquilizers
are mild CNS depressants which produce relaxation and reduce
anxiety with limited suppression of breathing and moderate impairment
of judgment and concentration. The drugs produce their effects
by interacting with the body's internal systems for relaxation
and stress control.
Low-dose effects
include mild sedation, muscular relaxation, and feelings of enhanced
well-being, while higher doses can produce drowsiness, confusion,
and dizziness. Recent studies indicate benzodiazepines may block
formation of long-term memories up to six hours after use.
While tranquilizers
are relatively safe and effective when used properly under a
doctor's supervision, the drugs still pose a variety of risks
to users.
Potentiation:
Tranquilizers
intensify effects of other CNS depressants, raising risks of
overdose even at nonintoxicating doses.
Overdose:
Tranquilizers,
particularly Valium, are consistently among the most widely used
drugs in accidental and intentional overdose. One-fifth of all
hospital admissions for suicide during 1990 involved benzodiazepines.
Dependence:
All tranquilizers
can cause psychological dependence with sustained use -- even
at therapeutic doses -- and withdrawal can be an agonizing, prolonged
process. Dependence is difficult to diagnose since symptoms of
withdrawal -- anxiety, depression, and insomnia -- parallel the
problems that the drugs are prescribed to treat.
Major tranquilizers
are used to treat psychotic disorders and are rarely abused,
since their effects are not felt as pleasurable.
Medical Uses: As a sedative, muscle
relaxant, anti-convulsant, and anti-anxiety agent. The major
tranquilizers are used in treatment of psychotic and major mood
disorders.
Main Dangers:
Hazards
include risks of overdose (either alone or in combination with
alcohol and other depressants) and high possibility of psychological
dependence with long-term use.
Withdrawal
Symptoms: With
meprobamate, similar to the barbiturates. Benzodiazepine tranquilizers
elicit a long-lasting withdrawal characterized by severe anxiety,
insomnia, and depression.
Signs of Use:
Disinhibition,
loss of coordination, fatigue, reduced motivation, confusion.
Narcotics
Examples:
Opium
and derivatives: codeine, morphine, heroin. Synthetics: methadone,
meperidine (Demerol®), hydromorphone (Dilaudid®), oxycodone
(Percodan®), pentazocine (Talwin-Nx®).
Actions: Narcotics act on the
central and parasympathetic nervous systems to slow body function,
reduce sensitivity to pain, and induce sleep. Low-dose or infrequent
use produces analgesia, euphoria, and stupor, blocking desire
for food, sex, and other activities. Higher dose and regular
use triggers a sense of detachment and reduced motivation.
Narcotics are
associated with a range of unwanted side effects, including itchiness,
constipation, and nausea and vomiting, arising from their direct
action on parasympathetic nerves.
Overdose:
High
doses profoundly suppress breathing and heart rate, causing death
by respiratory failure. Since users also quickly build tolerance
to the drugs, overdose risks are high.
Dependence:
All narcotics
carry a high potential for physical and psychological dependence.
Because a high level of tolerance to the drugs develops quickly,
addicted individuals are able to take many times a normal lethal
dose without significant adverse effects. At this stage, the
drugs are taken almost solely to ward off withdrawal.
Medical Uses:
To relieve
pain, cough, and diarrhea, and as a pre-anesthetic medication.
Narcotics are also administered to reduce chronic pain in the
terminally ill.
Main Dangers:
Overdose
and physical addiction. IV heroin users also face risks of AIDS
and other needle-related diseases. Unpredictable potency of street
heroin poses additional hazards. "Designer" forms of
the drug -- synthetic, lab-made, act-alike replicas of narcotics
-- carry serious risks of their own. One "designer"
form of heroin is linked with more than 130 overdose deaths and
a paralyzing nervous system disorder, Parkinson's disease.
Withdrawal
Symptoms:
Withdrawal begins three to eight hours after the last dose (depending
on the drug), and includes such flu-like symptoms as chills,
watery eyes, runny nose, nausea and vomiting. Other symptoms
include anxiety, irritability, cramps, and tremors. Withdrawal
peaks in 36 to 72 hours, but symptoms can persist as long as
10 days. Convulsions, coma, and death may occur.
Withdrawal symptoms
are quickly reversed by another dose of a narcotic drug.
Signs of Use: Constriction of pupils,
low response to pain, nausea or vomiting, lethargy, slow breath,
and alternating periods of wakefulness and sleep ("nodding
out"). Judgment and coordination are not impaired markedly
at low doses.
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