© 2019 Cengage. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
15
CHAPTER 6
Misuse of Barbiturates and Barbiturate-Like Compounds
LEARNING OBJECTIVES
After studying this chapter, students should be able to:
•
6.2: Understand the pharmacology, subjective effects, and complications of
barbiturates at appropriate prescribed levels
•
6.4: Describe substances similar to barbiturates
COURSE OUTLINE
Early Medical Treatment of Anxiety and Insomnia
History and Current Medical Uses of Barbiturates
The Misuse Potential of Barbiturates
Pharmacology of the Barbiturates
The Barbiturate-Like Drugs
Barbiturate Use and the Diagnostic and Statistical Manual of Mental Disorders (5th Edition)
COURSE OVERVIEW
The purpose of this chapter is to establish a foundation on which the student might understand
the evolution of anxiolytic/hypnotic medications within this culture, and the effects of many of
the older anxiolytic and hypnotic compounds introduced in the late 19th and early 20th
DISCUSSION QUESTIONS
Break-Out Discussion #1:
Are these really sedating agents? Barbiturates and barbiturate-like compounds were developed
more than a century ago. Their action does not affect only those specific neurons involved in the
process of inducing anxiety, insomnia, or consciousness, however. They affect every neuron that
accepts GABAa as a neurotransmitter, reducing the neurons’ firing rate. Thus, the action of the
barbiturates could be compared to the action of the fire blankets found in many laboratories;
when thrown over a fire, they not only smother the flames, but also cover such a wide area that
nearby objects are damaged as well.
Using the analogy offered above, the fire itself covers only a small area, possibly less than two or
three-square feet. When deployed, the fire blanket might cover twenty or thirty square feet,
damaging equipment and experiments uninvolved in the fire at the time. The barbiturates’
Questions
1. At what point should a compound no longer be considered advisable for human use? What
circumstances might affect this decision?
2. Are there any circumstances in which a compound with potentially dangerous side effects
should be administered anyway? What might those circumstances be, and who should be
allowed to make that decision?
Break-Out Discussion #2:
Drug development: When the barbiturates were first developed, the protocols for drug
development now used by the Drug Enforcement Administration were not in place. The
chemists who developed a new compound might be the test subjects for the same compound.
Although it is not a barbiturate, heroin provides an excellent example of this process: the
chemists who developed this compound injected it into themselves, thought that it made them
It often surprises students to learn that until the year 1938 there was no law in place that
prohibited the sale of compounds unsupported to be either effective or safe by clinical trials.
After a near-disaster in 1937 involving such a compound, Congress passed the Pure Food and
Drug Act of 1938 in the United States. Since then, more appropriate guidelines for use of human
test participants have been developed to hopefully protect the 20 million citizens in the United
States who are involved in a clinical trial of a drug each year (O’Meara, 2009).
died as a result of a specific disease. Other volunteers may have a medical disorder that they
hope will be cured by the treatment under development. Volunteers sign lengthy consent forms
prior to their admission to the study and are carefully screened to weed out individuals with
medical conditions that might confound the results. Those who meet the study criteria are then
Questions
1. Under what circumstances is it necessary to test a compound on human test participants? On
animals?
2. What do you believe is adequate compensation for a human test participant? What level of
compensation might induce you to volunteer yourself? If a friend were to express interest in
becoming a human guinea pig for a clinical research trial, what would you tell him or her?
Reference
O’Meara, A. (2009). Chasing Medical Miracles. New York: Walker & Company.
KEY CONCEPTS AND TERMS
Paraldehyde: A hypnotic that produces a noxious taste and unpleasant breath, first introduced
as a hypnotic in 1882
Bromide salts: Introduced in the mid-1800s as treatment for epilepsy, and then later as a
sedative and hypnotic
Diphenhydramine: An antihistamine with a strong sedative side effect
Medulla oblongata: Region of the brain, sometimes referred to as the brain stem, involved in
the control of respiration and temperature regulation
Photosensitivity: An extreme sensitivity to sunlight, which can be caused by some medications
Neuroadaptation: The process, once called “tolerance,” by which the nervous system adapts to
the constant presence of a foreign compound. This usually involves modification of the receptor
sites on the neurons affected by that compound. This term is usually applied to the brain’s
adjustments to the constant presence of a prescribed chemical, while the term “tolerance” is
applied to the same process when it involves an illicit compound
Cross-tolerance: Process through which an individual’s tolerance to one compound, say
alprazolam, is transferred to other compounds in the same class, such as diazepam, as well as to
similar compounds such as ethyl alcohol (all of which, in the example provided, are CNS
depressants)
Amblyopia: Loss of vision or decrease in vision, often referred to as “lazy eye”
Meprobamate: First introduced in 1955 as a “non-barbiturate” compound that could be used in
the daytime to treat anxiety and at higher dosage levels as a hypnotic agent, with a chemical
structure similar to that of the barbiturate
LO/STANDARDS CORRELATION CHART
A-head
LO
Standard – CACREP
Early Medical Treatment
of Anxiety and Insomnia
History and Current
Medical Uses of
Barbiturates
6.1:
Understand
the history of
barbiturates
3d: theories and etiology of addictions
and addictive behaviors
3e: biological, neurological, and
physiological factors that affect human
development, functioning, and behavior
Pharmacology of the
Barbiturates
Subjective Effects of
Barbiturates at Normal
Dosage Levels
Complications of
Barbiturate Use at Normal
6.2:
Understand
the
pharmacology,
subjective
effects, and
complications
of
3d: theories and etiology of addictions
and addictive behaviors
3e: biological, neurological, and
physiological factors that affect human
development, functioning, and behavior
levels
Effects of the Barbiturates
at Above-Normal Dosage
Levels
Neuroadaptation,
Tolerance, and Physical
Dependence on
Barbiturates
Barbiturate Use and the
Diagnostic and Statistical
Manual of Mental
Disorders (5th Edition)
6.3: Contrast
the
pharmacology,
subjective
effects, and
complications
of above
normal use of
barbiturates
with normal
prescribed
levels of use
3d: theories and etiology of addictions
and addictive behaviors
3e: biological, neurological, and
physiological factors that affect human
development, functioning, and behavior
The Barbiturate-Like Drugs
6.4: Describe
substances similar to
barbiturates
3d: theories and etiology of addictions
and addictive behaviors
3e: biological, neurological, and
physiological factors that affect human
development, functioning, and behavior