Toxicology Flashcards
(160 cards)
1
Q
Absorption of toxins in the GIT is by —- this process requires that the substance
cross cellular barriers.
A
passive diffusion
2
Q
In cases of drug overdose, these must be determined
A
CBC, serum electrolytes, BUN, glucose, urinalysis and blood gas
3
Q
Common substances causing acute toxicity:
A
alcohol, acetaminophen, salicylate, abuse substance
and carbon monoxide
4
Q
Routes of exposure
A
ingestion, inhalation and transdermal absorption
5
Q
single, short-term exposure to a substance
A
Acute toxicity
6
Q
repeated exposure for extended period of time
A
Chronic toxicity
7
Q
is the dose that would be predicted to produce a toxic response in 50% of the
population
A
TD50
8
Q
dose that would predict death in 50% of the population
A
LD50
9
Q
dose that would be predicted to be effective or have a therapeutic
benefit in 50% of the population
A
ED50
10
Q
most common abused drug; a CNS depressant.
causes diuresis by inhibiting ADH
A
Ethanol
11
Q
readily absorbed in the GIT and diffuses easily in tissues
abuse causes acidosis through accumulation of ketones and lactate and also t hrough
direct generation of hydrogen ions as alcohol is oxidized; also add osmolality to blood
A
Ethanol
12
Q
Specimen preferred for ethanol
A
Serum capillary and arterial blood samples
13
Q
hangover symptoms” are due to the effects of
A
acetaldehyde
14
Q
antidote for chronic intoxication:
A
diazepam
15
Q
must be used instead
of isopropanol in blood collection
A
Cleanser
16
Q
major metabolic pathyway: conversion of ethanol to acetaldehyde and acetyl coenzymeA
by
A
hepatic alcohol dehydrogenase
17
Q
methods for testing ethanol:
A
enzymatic, gas-liquid chromatography and electrochemical oxidation
18
Q
preferred method for testing ethanol:
A
enzymatic using alcohol dehydrogenase reagent
19
Q
common laboratory results for ethanol
A
elevated GGT, AST, AST/ALT ratio (> 2.0), HDL and MCV
20
Q
Fatal dose of ethanol
A
300-400 mL of pure alcohol consumed in less than one hour
21
Q
peak blood level of ethanol
A
withinan hour after intake of alcohol
22
Q
toxic blood level of ethanol:
A
> 500 mg/dl (for hemodialysis)
23
Q
a commonly used solvent and a contaminant of homemade liquors.
it is converted first to formaldehyde, then finally to formic acid in the liver by alcohol
dehydrogenase.
A
Methanol (wood alcohol)
24
Q
symptoms of intoxication: blurred vision, incoordination, slurred speech and coma;
A
Ethanol
25
symptoms of intoxication: frank blindness (ocular toxicity) and metabolic acidosis
Methanol
26
screening test for methanol
computation of osmolal gap
27
converted first to formaldehyde, then finally to ----- in the liver by alcohol
dehydrogenase.
Formic acid
28
preferred method for methanol
GC MS
29
fatal dose of methanol
60-250 mL
30
toxic blood level of methanol
> 50 mg/dl
31
rapidly absorbed by the GIT.
it is metabolized by hepatic alcohol dehydrogenase to acetone.
Isopropanol (rubbing alcohol)
32
symptoms of intoxication in isopropyl
CNS depression and hypertension
33
indication of toxicity in ethanol:
elevated levels of acetone in the blood and urine
34
preferred method isopropanol:
gas chromatography
35
antidote isopropanol:
Activated charcoal
36
common constituent of hydraulic fluid and antifreeze.
Ethylene glycol (1,2-ethanediol)
37
Ethylene glycol is converted to --- and --- by hepatic alcohol dehydrogenase.
oxalic acid and glycolic acid
38
symptoms of intoxication of ethylene glycol
metabolic acidosis, depressed reflexes, anuria and necrosis
39
indication of toxicity in ethylene glycol
deposition of calcium oxalate crystals in renal tubules
40
mode of treatment: for ethylene glycol
Inhibit the action of alcohol dehydrogenase
41
major metabolite for ethylene glycol (cause of acute toxicity and death)
glycolic acid (cause of acute toxicity and death)
42
preferred method for ethylene glycol
HPLC
43
fatal dose of ethylene glycol
100 grams
44
Almost all drugs of abuse are basic drugs (amine derivatives) which contain
benzene rings
45
barbiturates are _____ drugs
acidic
46
Many of the abused drugs act directly on dopaminergic neurotransmitter systems especially in ________
limbic system (small brain)
47
True or False:
A positive drug screening test can differentiate casual user from chronic or habitual user, likewise detect the time frame of using the drug, or dose of the drug taken
False: It cannot differentiate
48
modified forms of established drugs of abuse
Designer use
49
therapeutically used for treatment of narcolepsy and attentional deficit disorder
Amphetamines
50
increases mental alertness and physical capacity, and has anorectic property
Amphetamines
51
Amphetamines are structurally related to
dopamine and cathecolamines.
52
Amphetamines cause the release (together with cocaine) of ------------- from the brain leading to a "pleasant feeling" (so called "high') among users.
dopamine
53
derivative of methamphetamine is a popular recreational abused drug (designer drug); has psychedelic effects.
3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy')
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treatment of hyperactive children
Ritalin
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Amphetamine-like compounds
ephedrine, pseudoephedrine and phenylpropanolamine
56
presence of antihistamine (diphenhydramine) causes ---- in amphetamine detection
false positive reaction
57
Sign of acute intoxication of amphetamine
hyperpyrexia
58
Acute psychotic syndromes of amphetamine
auditory and visual hallucinations, suicidal tendency and paranoia
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palpitation, hypertension, cardiac arrhythmias, convulsions, pancytopenia
mental impairment and teeth grinding
Toxic effects of amphetamines
60
Anabolic steroids are chemically associated to the male hormone testosterone
dihydrotestosterone and testosterone
61
improves athletic performance by increasing muscle mass
anabolic steroids
62
toxic effects of anabolic steroid
chronic hepatitis
atherosclerosis
abnormal platelet
aggregation
cardiomegaly
63
Naturally occurring cannabinoids:
marijuana and hashish
64
most potent component or the psychoactive substance of marijuana
lipophilic substance, distributes in the adipose tissues; it easily enters the brain; it induces a sense of well-being and euphoria; it is a hallucinogen
Tetrahydrocannabinol (THC)
65
Single-use: THC-COOH can be detected in urine for
3-5days
66
Chronic: THC-COOH can be detected in urine for
4 weeks for chronic user
67
Principal psychoactive agent of Cannabinoids
delta-9-tetrahydrocannabinol
68
Urinary metabolite of THC
11-nor-deltatetrahydrocannabinol (THC-COOH)
69
Psychologic effects of THC
reddening of the conjunctiva and increased pulse rate
70
Toxic effects of THC
paranoia, disorientation, altered physical senses and bronchopulmonary disorders
71
an alkaloid salt (ecgonine) that can be taken directly (insuflation of IV) or by inhalation/snorting.
Cocaine (Crack)
72
Cocaine is derived from coca plant ---- and used as additive to some food
Erythroxylon
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potent CNS stimulant that elicits a sense of excitement and euphoria; increasesphysical
activity
Cocaine
74
True or False:
Cocaine has not been considered as an addictive drug - it does not reflect the true dependence
commonly seen in abusers of barbiturates and opiates.
True
75
True or false:
Cocaine does not easily pass to placenta and mammary glands
False: it causes mental retardation, slow mental development and drug dependence in newborns
76
It can caused malformations in uterus.
It can cause sudden death due to direct toxicity to myocardium (cardiac toxicity) - it
induces vasoconstriction, platelet aggregation and synthesis of plasminogen activator inhibitor.
Cocaine
77
Cocaine single use, it can be detected in urine for up to
3 days
78
Chronic use of cocaine can be detected up to
20 days
79
Inhibitor of coccaine
Prozac
80
Treatment for cocaine addiction
Benzodiazepine
81
hypertension, arrhythmias, seizures and myocardial infarction
Toxic effects of coccaine
82
Urine metabolite of Cocaine
benzoylecgonine (sensitive and specific)
83
capable of analgesia, sedation and anesthesia
Opiates
84
Opiates are derived from
Opium poppy
85
Naturally occuring opiates
opium, morphine and codeine
86
Chemically modified opiates
heroin
hydromorphone
oxycodone (Percodan)
87
Common synthetic opiates
meperidine (Demerol)
methadone (Dolophine)
propoxyphene (Darvon)
pentazocine (Talwin) and fentanyl (Sublimaze)
88
antitussive drug from opiates
Codeine
89
a nonbicyclic drug that binds with morphine in the brain
methadone
90
more potent analgesics than morphine: opiate
Fentanyl "lollipops" or "patches
91
Commonly tested opiates:
morphine and codeine
92
Major cause of drug-related death: opiates
darvon overdose combine with alcohol
93
Major metabolites of heroin
N-acetylmorphine (heroin) and morphine
94
Major metabolites of heroin
N-acetylmorphine (heroin) and morphine
95
Withdrawal symptoms of heroin
cold sweats, nightmares and hypothermia
96
Antagonist for opiate overdose
naloxone (narcan)
97
Toxic effects of opiates
respiratory acidosis, myoglobinuria, cardiopulmonary failure and
pupillary constriction ("pin-point pupils")
98
a metabolite of heroin; a powerful analgesic; used in the treatment of acute congestive heart failure
binds to mu-receptors in the limbic system (CNS) producing analgesic effect.
morphine
99
increase liver and pancreatic enzymes
Morphine and meperidine
100
highly addictive (true physical dependence); crosses the blood-brain barrier - elevated levels in the CNS; taken by IV administration
Heroin
101
a depressant, stimulant, and has hallucinogenic and anaesthetic properties
It can be ingested or inhaled by smoking
Phencyclidine (angel dust or angel hair)
102
______ is unchanged when excreted in the urine
acidification of the urine helps in immediate excretion of phencyclidine
10-15%
103
Physiologic effects of Phencyclidine
analgesia and anaesthesia
104
Major metabolite of phencyclidine
Phencyclidine HCL
105
Mode of Treatment for Phencyclidine
Isolation (kept in quiet, dark room)
106
Toxic effects of phencyclidine
tachycardia, seizure and coma (eventually death)
107
Therapeutic roles and they are CNS depressants
Used also to potentiate the effects of heroin
Sedative hypnotics: barbiturates and benzodiazepines
108
Commonly abused barbiturates
secobarbital
pentobarbital
phenobarbital
andthiopental
109
Commonly used benzodiazepines
diazepam (Valium)
chlordiazepoxide (Librium)
lorazepam (Ativan)
110
Barbiturates are condensation products of
urea and malonic acid.
111
used for treatment of cocaine addiction
Benzodiazepines
112
clinical use for rapid control of acute seizure activity; a minor tranquilizer.
Diazepam
113
Phenobarbital structurally resembles
phenytoin (Dilantin).
114
Toxicity of this agents is initiated by sedative hypnotics are initiated by
ethanol
115
Major metabolite of phenobarbital
secobarbital (barbiturates)
116
Barbiturate chemoadsorbent
Activated charcoal
117
Toxic effects of Sedative hypnotics
Cheyne-Stokes respiration, depression,cyanosis, areflexia, stupor, coma
118
a semisynthetic indol alkylamine - hallucinogen
It is one of the most potent pharmacologic materials known
it produces effects at low doses - 20ug ( IV or ingestion)
Lysergic Acid Diethylamide (LSD, Lysergide)
119
Most common adverse reaction of LSD
panic reaction - badtrip
120
Toxic effects of LSD
blurred or "undulating vision" and synesthesia
121
a 2,3-disubstituted quinazoline with anesthetic, antihistamine and antitussive properties.
also has sedative-hypnotic properties; a hallucinogen
Methaqualone
122
This abused drug has similar symptoms of toxicity to barbiturates, as well as pyramidal signs (hypertonicity, hyperreflexia and myoclonus).
Methaqualone
123
Chemoadsorbent of methaqualone
activated charcoal
124
produced the same "pleasant feeling" observed in amphetamines
No available screening nor confirmatory test for identification of these drugs
Piperazines
125
Major derivatives of piperazines
N-benzylpiperazines (B2P or A2) and phenylpiperazines
126
Minor derivatives piperazanines
1-(3-4-methylene-dioxybenzyl) piperazine (MDMP)
1-(3-trifluorometylphenyl) piperazine (TFMPP or Molly)
127
Popular piperazines:
BZP and TFMPP
128
Toxic effects of piperazines
tachycardia, hypertension, hyperthermia, psychomotor agitation and sore nasal and throat passages
129
derivatives of serotonin; some compounds are present in plants
Tryptamines
130
Examples of tryptamines
N,N-dimethyltryptamine (DMT)
psilocin
131
a short-term hallucinogen ("businessman's lunch"); taken by smoking
DMT
132
a component of "magic mushrooms" (psilocybe); a hallucinogen
Psilocycin
133
enhances the hallucinogenic effect of tryptamines
Monoamine oxidase inhibitor (B-carbolines)
134
a tea which contains tryptamines.
Ayahuasca
135
Antagonist of tryptamines
benzodiazepines
136
Toxic effects of tryptamines
tachycardia, hypertension, dystonia, seizures, rhabdomyolysis and paralysis
137
Specimen Considerations for tryptamines
Alcohol in blood samples may be analyzed even after a moment of delay provided the
samples in tubes remain sealed, because blood lacks the enzyme that metabolize it.
Urine temperature is a vital factor to assure that it is freshly voided (abused drug).
Aspiration of gastric contents or vomitus may reveal tablets or capsules from which the
ingested drug can be determined.
138
____ sample for toxicology assay has the advantage of knowing the complete composite of
drugs that have been ingested over a longer period than blood samples.
Urine
139
Examination of blood has the advantage of ____ to design treatment plan and monitoring the success of treatment.
identifying current circulating drugs
140
Drugs when deposited in hair, are generally present in relatively ____ levels
low
141
sweat testing, parent drug is ----- than metabolites
increased
142
saliva testing, drug concentration in it reflects the ------ fraction
free or active
143
2 basic techniques for identification of drugs
immunochemical and chromatography
144
Alcohol is measured from blood using alcohol dehydrogenase as reagent.
It quantitates the sum of all alcohols present in a sample.
It does not distinguish alcohols from its metabolites during quantitation.
Enzymatic test
145
Different analyte selectivity is based on different physicochemical principles of separation without changes in instrumental hardware, a distinct advantage of this technique.
Recent variant of TLC that includes the advantages of HPLC.
Capillary Electrophoresis
146
This assay is done in one solution without separation
Homogenous immunoassays
147
This method uses enzyme-labeled drug that competes with the drug in the sample.
In this reaction, the active site of the enzyme is blocked with the antidrug antibody, resulting to decreased enzymatic activity.
Enzyme Mediated Immunologic Technique (EMIT)
148
Chromatographic methods:
method uses serum, urine or gastric fluid for analysis.
Extraction of drugs is pH dependent - acidic drugs at pH 4.5 (barbiturates) and aikaline drugs (opiates, amphetamines) at pH 9.0.
Thin layer chromatography (TLC)
149
can be used to confirm positive test results from a screening assay (nonvolatile compounds).
can also be used for detection of poisons in acute or chronic intoxication, therapeutic drug identification and quantitation, pharmacokinetics and drug
metabolism studies.
Liquid Chromatography-Mass Spectrospcopy (LC-MS)
150
allows quantitative measurement of drugs as well as separation of these same drugs, especially tricyclic antidepressants including its active and inactive metabolites.
It may be used as an alternative to GC-MS in definitive identification of drugs.
High performance liquid chromatography (HPLC)
151
the legally accepted method for ethanol testing
Gas Liquid Chromatography (GLC)
152
detection of amphetamines
GC with Infrared Spectroscopy
153
the gold standard for confirmation of screening methods such as TLC and EMIT
allows for detection of low levels of drugs like cocaine and drug metabolites.
Gas Chromatography-Mass Spectroscopy (GC-MS)
154
Urine is the preferred sample especially in drug testing because of the following reasons:
1. Drugs and their metabolites are present in higher concentrations in urine than in blood.
2. Larger sample volumes are easily collected.
3. There is no pain or discomfort when collecting the sample.
4. The process of obtaining the sample is noninvasive.
155
Factors resulting to incorrect drug testing results:
1. Presence of detergents will result to alkaline pH.
2. Use of sodium chloride (table salt).
3. Low specific gravity (diluted urine)
4. High pH (alkaline urine)
5. Blood in urine (hematuria)
156
Urine drug detection is from about ------- - but most drugs are undetectable in ------
12 hours to three weeks
2-5 days
157
Drug detection in ----- has longer positivity (months)
hair
158
best specimen for alcohol determination
whole blood
159
Adulteration is a means of tampering the specimen for drug testing, to make the specimen ---- for drugs
falsely negative
160
Any confirmatory method is valid, provided it is a completely different method from the primary
one (TLC can confirm ---)
EMIT
