8 The Encyclopedia of Addictive Drugs
effects particularly harmful to young persons whose bodies are still devel-
oping. Attainment of adult height can be thwarted, and sexual organs can be
damaged. Rising concern about injury to younger athletes caused the strict
regulations of scheduling to be applied to these drugs, although other types
of control (requiring prescriptions and suppressing nonmedical sales) had
long been in place.
Scheduling is an element of law enforcement. Penalties for illegal use or
possession of a drug depend partly upon its schedule. A related purpose of
scheduling involves control of scheduled substances through tracking pre-
scriptions written by health care practitioners and by tracking inventory rec-
ords of pharmacies.Pregnancy Categories
Legal drugs are placed in a Pregnancy Category, a system used to classify
the risk of birth defects if the substance is used by a pregnant woman. Dif-
ferent countries have different systems of categories. The alphabetical entries
in this book use the U.S. Food and Drug Administration system that was in
place as the twenty-first century began.Pregnancy Category A. Studies using pregnant women do not show birth defects
caused by the drug in the first trimester, and evidence has not emerged show-
ing risk later in pregnancy.
Pregnancy Category B. Studies using pregnant women have not been conducted,
but experiments with pregnant animals fail to demonstrate birth defects. Al-
ternatively, animal experiments have produced birth defects, but studies using
pregnant women have not.
Pregnancy Category C. Animal experiments have produced birth defects, but no
studies have used pregnant women to examine the potential for human birth
defects. Alternatively, no animal or human studies have been conducted to
determine the drug’s potential for causing birth defects.
Pregnancy Category D. Studies or reports of clinical experience indicate that the
drug causes human birth defects, but using the drug during pregnancy may
be so important to the woman’s health that fetal risk is justified (for example,
no acceptable alternative therapy is available to deal with the woman’s illness).
Pregnancy Category X. Animal or human studies or clinical reports indicate the
drug causes birth defects, and the drug’s potential benefits for a pregnant
woman’s health do not justify risk to fetal development (for example, accept-
able therapies are available that do not involve the drug).Often a birth defect is thought of as something apparent upon birth, but
scientists have found that some problems from fetal drug exposure such as
cancer do not become evident until adulthood. And even though problems
might not be observed among infants of women who used a certain drug
during pregnancy, that fact does not necessarily mean the drug has no impact
on fetal development. Drugs discussed in this book typically affect a user’s
brain, suggesting that they may be particularly prone to harming fetal brain
and nervous system development. Due to the course of fetal development,