brain that causes erratic and extreme NERVOUS SYS-
TEMresponses affecting brain function as well as
vital functions such as regulation of blood pres-
sure, heart rate, and body temperature.
See alsoALCOHOL INTERACTIONS WITH MEDICATIONS;
AMPHETAMINES; BENZODIAZEPINES; HYPNOTICS; PRESCRIP-
TION DRUG ABUSE; SUBSTANCE ABUSE PREVENTION; SUB-
STANCE ABUSE TREATMENT.
benzodiazepines Drugs that depress CENTRAL
NERVOUS SYSTEMfunctions. In large part benzodi-
azepines have replaced BARBITURATESin many ther-
apeutic applications and have numerous
therapeutic uses including as MUSCLE relaxants,
antianxiety medications, and sleep aids. Doctors
also prescribe benzodiazepines to relieve the
symptoms of WITHDRAWAL SYNDROME. Benzodi-
azepines are class 4 SCHEDULED DRUGSin the United
States, requiring a physician’s prescription for legal
use and possession. As drugs of abuse, benzodi-
azepines are popular for easing the symptoms of
“coming down” from other drugs. They may also
cause sensations similar to moderate ALCOHOL
INTOXICATION. Benzodiazepines are among the most
frequently abused prescription medications. Risks
of long-term, chronic abuse may result in ADDIC-
TIONand symptoms such as HALLUCINATION, trem-
bling, and confusion.
COMMON BENZODIAZEPINESalprazolam chlordiazepoxide
clobazam clonazepam
clorazepate clorazepate
diazepam estazolam
flurazepam halazepam
lorazepam midazolam
oxazepam prazepam
quazepam temazepam
triazolam
See also GENERALIZED ANXIETY DISORDER (GAD);
HYPNOTICS; PRESCRIPTION DRUG ABUSE.
blood doping Actions to boost the ability of the
BLOODto carry oxygen by increasing the volume of
red blood cells in the blood circulation. Red blood
cells (erythrocytes) contain HEMOGLOBIN, protein
molecules that bind with oxygen molecules in the
LUNGS. The two commonly used methods of blood
doping are BLOOD TRANSFUSIONand ERYTHROPOIETIN
(EPO) supplementation. Doctors may use either of
these methods therapeutically to treat certain
types of ANEMIAand to maintain the level of or
hasten the return of blood cells after
CHEMOTHERAPY. Blood doping is an abuse of these
methods done to improve athletic performance by
increasing AEROBIC CAPACITY, typically among ath-
letes who compete in ENDURANCEevents. However,
athletic organizations worldwide prohibit blood
doping at all levels of competition, and many rou-
tinely test athletes for evidence of it.Blood Transfusions
Blood transfusion is usually of packed red blood
cells and may be homologous (from a donor) or
autologous (the person’s own blood). For autolo-
gous transfusion, the person may undergo HEMO-
PHORESIS, in which blood withdrawn from the
body undergoes cell separation; the components
other than the red blood cells are returned to the
blood circulation. The concentrated red blood cells
collected via hemophoresis are then refrigerated
or frozen to store them until a few days before a
competition. The athlete receives his or her own
red blood cells back via transfusion, boosting the
number of red blood cells in the blood. For
homologous transfusion, the athlete receives a
transfusion of red blood cells collected from
donors.Erythropoietin (EPO)
EPO is a natural HORMONEthe body produces to
stimulate theBONE MARROWto produce erythro-
cytes. EPO supplement, which became available in
the late 1980s, is a recombinant hormone that
intensifies this action. Injections of EPO thus cause
the bone marrow to produce extra red blood cells,
increasing their presence in the blood. Because it
is far easier than blood transfusion to use in secret,
EPO is the favored method of blood doping.Health Risks and Complications
Risks of blood doping include blood clots that can
cause HEART ATTACKor STROKEand increased viscos-
ity (thickness) of the blood, which strains the
HEARTand can cause CARDIOMYOPATHY and HEART
FAILURE. Homologous blood transfusions carry the
risk of contracting a bloodborneINFECTIONsuch as324 Substance Abuse