Scheduling of Controlled Substances

A “controlled substance” is a drug or substance of which the use, sale, or distribution is regulated by the federal government or a state government entity.

These controlled substances are listed specifically or by classification on the federal level in the Controlled Substances Act (CSA) or in Part 1308 of the Code of Federal Regulations. The purpose of the CSA is to minimize the quantity of useable substances available to those who are likely to abuse them.

At the same time, the CSA provides for the legitimate medical, scientific, and industrial needs
of these substances in the U.S.

Eight factors are considered when determining whether or not to schedule a drug as a controlled substance:

1. Actual or relative potential for abuse.
2. Scientific evidence of pharmacological effect.
3. State of current scientific knowledge.
4. History of current pattern of abuse.
5. Scope, duration, and significance of abuse.
6. Risk to the public health.
7. Psychic or physiological dependence liability.
8. Immediate precursor.

The definition of potential for abuse is based upon an individual taking a drug of his own volition in sufficient amounts to cause a health hazard to himself or to others in the community. Data is then collected to evaluate three factors: (1) actual abuse of the drug; (2) the clandestine manufacture of the drug; (3) trafficking and diversion of the drug or its precursors from legitimate channels into clandestine operations. Pre-clinical abuse liability studies are then conducted on animals to evaluate physiological responses to the drug. At this point, clinical abuse liability studies can be conducted with human subjects, which evaluate preference studies and epidemiology.

Accumulating scientific evidence of a drug’s pharmacological effects involves examining
the scientific data concerning whether the drug elicits a stimulant, depressant, narcotic, or
hallucinogenic response. A determination can then be made as to how closely the pharmacology
of the drug resembles that of other drugs that are already controlled.

Evidence is also accumulated about the scientific data on the physical and chemical
properties of the drug. This can include determining which salts and isomers are possible and
which are available. There is also a concern for the ease of detection and identification using
analytical chemistry. Since many controlled substances have the potential for clandestine
synthesis, there is a requirement for evaluating precursors, possible synthetic routes, and
theoretical yields in these syntheses. At this phase of the evaluation, medical uses are also
evaluated.

The next three factors—(1) history and patterns of abuse; (2) scope, duration, and
significance of abuse; and (3) risks to public health—all involve sociological and medical
considerations. The results of these studies focus on data collection and population studies.
Psychic and physiological dependence liability studies must be satisfied for a substance to be
placed into Schedules II through V. This specific finding is not necessary to place a drug into
Schedule I. A practical problem here is that it is not always easy to prove a development of
dependence.

The last factor is one that can involve the forensic analyst. Under the law, an “immediate
precursor” is defined as a substance that is an immediate chemical intermediary used or likely
to be used in the manufacture of a specific controlled substance. Defining synthetic pathways
in the clandestine production of illicit controlled substances requires knowledge possessed by
the experienced analyst.

A controlled substance will be classified and named in one of five schedules. Schedule I
includes drugs or other substances that have a high potential for abuse, no currently accepted
use in the treatment of medical conditions, and little, if any, accepted safety criteria under the
supervision of a medical professional. Use of these substances will almost always lead to abuse
and dependence. Some of the more commonly encountered Schedule I controlled substances are heroin, marijuana, lysergic acid diethylamide (LSD), 3,4-methylenedioxy-amphetamine
(MDA), and psilocybin mushrooms.

Progressesing from Schedule II to schedule V, abuse potential decreases. Schedule II
controlled substances also include drugs or other substances that have a high potential for
abuse, but also have some currently accepted, but severely restricted, medical uses. Abuse of
Schedule II substances may lead to dependence which can be both physical and/or psychological. Because Schedule II controlled substances do have some recognized medical uses, they are usually available to health professionals in the form of legitimate pharmaceutical preparations.

Cocaine hydrochloride is still used as a topical anesthetic in some surgical procedures. Methamphetamine, up until a few years ago, was used in the form of Desoxyn to treat hyperactivity in children. Raw opium is included in Schedule II. Amobarbital and secobarbital, which are used as central nervous system depressants are included, as is phencyclidine (PCP) which was used as a tranquilizer in veterinary pharmaceutical practices. In humans, PCP acts as a hallucinogen.

Though many of the substances seized under Schedule II were not prepared by
legitimate pharmaceutical entities, cocaine hydrochloride and methamphetamine are two
examples of Schedule II drugs which, when confiscated as white to off-white powder or
granules in plastic or glassine packets, have almost always been prepared on the illicit market
for distribution. As one progresses from Schedules III through V, most legitimate pharmaceutical preparations will be encountered.