Page 428 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Toxicity of Drugs of Abuse Chapter | 22 395

VetBooks.ir body builders at one time, and is currently used to treat STIMULANTS
narcolepsy. Industrial solvents γ-butyrolactone (GBL)
The major illicit drugs classified as stimulants are cocaine
and 1,4-butanediol (BD) are metabolized to GHB. BD
is available in printer ink cartridges and has been sold and the amphetamines. Cocaine is a plant alkaloid, and
amphetamines are a large group of compounds, including
as a supplement at health food stores (Smith et al.,
prescription drugs such as methylphenidate, sold as
2002; McDonough et al., 2004; Anonymous, 2011). BD
Ritalin, and methamphetamine, which is produced in clan-
was also used as a substitute for 1,5-pentanediol in the
destine laboratories. Stimulants in general act on the
production of a children’s craft product called “Aqua
ANS, usually on adrenergic receptors. Popular “club
Dots” in the United States and “Bindeez” in Australia
drug” MDMA, or “ecstasy,” also has significant action on
(Suchard et al., 2009). The substitution was made in
serotonin receptors. Related to amphetamines are cathi-
2007 and resulted in clinically affected children. GHB
nones. Naturally occurring cathinone is found in the plant
is most commonly sold as a clear liquid in small vials
Catha edulis, known as Khat, but synthetic forms, often
and added to bottled water (Smith et al., 2002; Rimsza
sold as “bath salts,” have become popular in the United
and Moses, 2005). Street names include “Liquid X” or
States since 2010. Various legally available compounds
“liquid ecstasy,” “soap” or “salty water” because of the
act as stimulants through various mechanisms. These
flavor of the product, “easy lay,” “Georgia homeboy,”
include nicotine, caffeine, and related compounds, and are
“grievous bodily harm,” “G,” “goop,” “gib,” or
discussed elsewhere in the text. Areca alkaloids, described
“scoop.”
below, are commonly used as stimulants across much of
GHB receptors are present in the hippocampus, cortex,
Asia and are available in some parts of the United States
and other areas of the brain (McDonough et al., 2004).
and Europe.
GHB is involved in regulation of sleep cycles, body tem-
perature, memory, glucose metabolism, and dopamine
levels (Smith et al., 2002). GHB can also be converted Cocaine
back to GABA. Human death has been reported at an oral
GHB dose of 5.4 g, but some patients have survived doses Cocaine is the natural alkaloid of the shrubs Erythroxylun
of 29 g. The LD 50 for rodents and rabbits is approxi- coca and Erythroxylun monogynum, originally from the
mately 2 g/kg. GHB is rapidly absorbed from the gastro- Andes Mountains in South America and most commonly
intestinal tract, and, because it is highly lipophilic, it grown in Bolivia, Peru, and Columbia (Queiroz-Neto
readily crosses the blood brain barrier. GHB is rapidly et al., 2002; Volmer, 2005; Anonymous, 2011).
metabolized to carbon dioxide, though 2% 4% of a given Traditionally, E. coca leaves are brewed into tea by those
dose can be excreted in the urine (Smith et al., 2002; native to the Andes Mountains, who share this delightful
Gable, 2004). Half-life is dose dependent. beverage with unsuspecting tourists in order to counter
Clinical signs attributed to GHB usually occur within the effects of the high altitude. Cocaine is a Schedule II
half an hour of ingestion and include euphoria, reduced drug used for topical anesthesia and vasoconstriction of
anxiety, and drowsiness. CNS depression sometimes pro- mucous membranes (Kisseberth and Trammel, 1990). At
gresses to loss of motor control, unconsciousness, and times, it has been second only to marijuana in illegal con-
respiratory depression (Smith et al., 2002; McDonough sumption in the United States (Dumonceaux, 1995;
et al., 2004; Rimsza and Moses, 2005). Clinical signs Queiro-Neto et al., 2002; Vitale and van de Mheen,
reported in children ingesting “Aqua Dots” were vomit- 2005). Based on surveys in the 1980s, approximately 15%
ing, ataxia, and coma (Suchard et al., 2009). Seizures of the US population had tried cocaine (Kabas et al.,
have been reported, and bradycardia and hypothermia are 1990). More recent surveys of high-school students in the
reported in nearly a third of overdose patients. US found that 5% 6.4% had used cocaine (Eaton et al.,
Treatment consists of decontamination of the intubated 2010; Latimer and Zur, 2010).
patient with either gastric lavage, after large ingestion, or Cocaine is sold as a powdered white salt, cocaine
activated charcoal—emetics are contraindicated because HCl, ranging in purity from 12% to .60% (Kisseberth
of the rapid onset of CNS depression—and close monitor- and Trammel, 1990). It is usually diluted or “cut” with
ing of respiratory, cardiovascular, CNS function, and inert ingredients such as lactose, inositol, mannitol, corn
body temperature. Supportive care is instituted based on starch, or sucrose, or with active compounds including
clinical signs. Seizures have been treated with benzodia- procaine, lidocaine, tetracaine, caffeine, amphetamine, or
zepines. Patients who appear stable should be monitored quinine. Cocaine cut with levamisole has been associated
for at least 8 h (Smith et al., 2002). GHB is difficult to with severe adverse effects in users, including agranulocy-
analyze for, and results are difficult to interpret because tosis and vasculitis (Buchanan et al., 2010; Wiegand,
this compound is rapidly metabolized and normally pres- 2010). The water soluble salt can be injected, ingested, or
ent in the body. insufflated (Rimsza and Moses, 2005; Anonymous, 2011).