MIDTERMS LECTURE Flashcards
(124 cards)
1
Q
Contact providing opportunity of obtaining a poisonous dose
A
EXPOSURE
2
Q
Different toxic responses may arise from different:
A
- Routes of exposure- ways how did you expose
- Frequencies of exposure- everyday ba?
- Duration of exposures- (acute (reversible) vs. chronic (irreversible) )
3
Q
Types of exposure
A
- Intentional- cigarette smoker
- Non-intentional- nonsmoker and 2nd hand smoker
*Toxicology studies involve intentional exposures
4
Q
ROUTES OF ENTRY OF EXPOSURE
A
a. Inhalation
b. Oral or by ingestion
c. Percutaneous or by injection
d. Dermal or ocular absorption
5
Q
ROUTES OF EXPOSURE OF TOXICANTS
A
IV/IM
Inhalation
Intradermal
Topical
Subcutaneous
6
Q
_________ is defined as the length in time when a toxic substance is exposed to a person or how frequent it had caused its toxicity.
A
Duration
7
Q
TYPES OF DURATION OF EXPOSURE
A
Short term (Acute)- a single exposure lasting less than 24 hours
Long term (Chronic)- exposures are essentially for the lifetime of the species
Repeated
8
Q
2 TYPES OF REPEATED DURATION OF EXPOSURE
A
o Sub-chronic: Repeated exposures of less than a lifetime (e.g., 3 months)
o Sub-acute: Repeated for up to 30 days
9
Q
ENUMERATE COCAINE SIDE EFFECTS (Brain, throat, lungs, systemic, nose, teeth, skin, heart)
A
Brain
- Increased risk of stroke
- reduce attention
-lethargy
-insomnia
Lungs
-dyspnea
-asthma
-chest pain
-bronchospasm
Throat
-horse voice
-soreness
Systemic
-eosinophilia
-fever
Nose
-rhinorrhea (discharge)
Teeth
-Bruxism (abrasion)
Heart
- increase heart infarction
Skin
-Pruritus
10
Q
Type of exposure that toxic symptoms are expressed after repeated applications for a timeframe less than half the life expectancy of the organism- but more often than a single dose or multiple doses applied for only a short time
A
Sub chronic exposure
11
Q
Exposure classes (toxicants in food, air, water, and soil as well as toxicants characteristic of domestic and occupational settings). Give examples of toxicants in food and soil
A
TOXICANTS IN FOOD
- Salmonella
- Shigellosis
- Vibrio Cholera
- Typhoid fever
- E.coli
- Cyanide
- Amiba Virus
Toxic in Soils
- Tetanus
- Fungal Infection
12
Q
Example of systemic exposures
A
- rabies (affects in brain)
- Johnson Powder (Talc)
= Mesothelioma cancer in lungs (Because of asbestos)
Ex: can get in long term exposure like construction worker
13
Q
Example of local exposures
A
Example: Cosmetics (affected only in one area)
14
Q
How many certain general symptoms suggested the possibility of a number of poisons, (local exposure)
A
13
15
Q
1) Sudden death (ABC)
A
aconitine, barium compounds and cyanide
16
Q
2) Eyes (EMPAC)
A
ergot, morphine, pilocarpine, atropine and cocaine
17
Q
4) Mouth (APA)
A
atropine, pilocarpine and ammonia
18
Q
5) Skin (APSAAA)
A
atropine, pilocarpine, strong acids (burning sensation) and alkalies (melting sensation), cyanosis produced by aniline, acetanilide
19
Q
6) GIT (MEFp)
A
metals, ergot and food poisons
20
Q
7) Cardiovascular system (QDER)
A
quinidine, digitalis, ephedrine and reserpine
21
Q
8) Liver (CTC)
A
carbon tetrachloride and chloroform
22
Q
9) Kidney (PS)
A
phenol and sulphonamides
23
Q
10) Nerves (AA)
A
peripheral neuritis due to antimony and arsenic
24
Q
11) Skeletal muscle (CF
A
curare and flaxedil
25
12) Blood changes (BH)
anaemia by benzene, haemolysis due to saponins, leukopenia by benzene
26
13) CNS (SPBEA)
strychnine, picrotoxin, barbiturates, ether, alcohol
27
EXPOSURES THAT REDUCE LIFE EXPECTANCY BY 8 MIN. GIVE 5 ONLY
* Smoking 1.4 cigarettes
* Living 2 months with a cigarette smoker
* Eating 100 charcoal-broiled steaks
* 1 X-Ray (in a good hospital)
* Eating 40 tablespoons of peanut butter
28
SPETRUM OF UNDESIRED EFFECTS (5)
1. Allergic reactions (chemical allergies)
2. Idiosyncratic reactions
3. Immediate vs. delayed toxicity
4. Reversible vs. irreversible toxicity
5. Local vs. systemic toxicity
29
4 TYPES OF EFFECTS
1 Local effect
2. Systemic effect
3. Cumulative effect
4. Poisonous effect
30
* The site of action takes places at the point of contact
Local Effect
31
* The site: skin, mucous membrane of the eyes, nose, mouth, throat or anywhere the along the respiratory or gastrointestinal system
Local Effect
32
* The toxic substance has been absorbed and distributed throughout the body
Systematic Effect
33
* Over a period of time, the material is only partially excreted and the remaining quantities are gradually collected.
Cumulative Effects
34
* The retained toxic compound accumulates and becomes great enough to cause pathological response.
Cumulative Effects
35
Cumulative Effects examples:
- Silica dust
- Asbestos
- Smoker
- Drinking soda
36
* A toxic substance is absorbed and distributed by the blood stream throughout the body
Poisonous Effect
37
* Absorption reaches a point where it causes impairment of physiological function
Poisonous Effect
38
EFFECTS OF TOXICANTS
o Carcinogen
o Mutagen
> Vurkih- causes inflammation of neck
> Papillomaviruses- causes warts
o Reproductive hazard
> nabaog
o Teratogenic
> Pregnant women experiences (Focomelia)
39
DEFINITIONS
LD- ?
ED-?
LD- lethal dose
ED- Effective dose
40
LD & ED OF Therapeutic Margin
TM = LD50% - ED50%
41
LD & ED OF Margin of Safety:
MOS = LD5% - ED95%
42
LD & ED OF Safety Index
SI = LD5%/ED95%
43
LD & ED OF Therapeutic Index
TI = 50%/ED 50%
44
RELATIVE TOXICITY CLASSIFICATION
Extremely Topic= Taste (1 grain)
Highly Topic= 1 tsp
Moderately Toxic= 1 oz
Slightly Toxic= 1 pt
Practically nontoxic= 1qt
Relatively harmless= >1qt
45
DEFINE THE LETHAL OF EACH CHEMICAL; Sugar (sucrose)
3 quarts
46
DEFINE THE LETHAL OF EACH CHEMICAL; Alcohol (ethyl alcohol)
3 quarts
47
DEFINE THE LETHAL OF EACH CHEMICAL; Salt (sodium chloride)
1 quart
48
DEFINE THE LETHAL OF EACH CHEMICAL; Herbicide (2, 4-D)
One half cup
49
DEFINE THE LETHAL OF EACH CHEMICAL; Arsenic (arsenic acid)
1-2 teaspoon
50
DEFINE THE LETHAL OF EACH CHEMICAL; Nicotine
One half spoon
51
DEFINE THE LETHAL OF EACH CHEMICAL; Food poison (botulism)
Microscopic
52
What are the 4 Types of Toxic Effects
Organ Damage- ozone, lead
Mutagenesis- UV light
Carcinogenesis- benzene, asbestos
Teratogenesis- Thalidomide
53
Enumerate all the TARGET ORGAN TOXICITY (clerrksi)
Central Nervous System – lead
Liver - ethanol, acetaminophen
Eye - UV light (sunlight)
Respiratory Tract - tobacco smoke, asbestos, ozone
Reproductive System – dibromochloropropane
Kidney – metals
Skin - UV light, gold, nickel
Immune System – isocyanates
54
DOSE UNITS ENUMERATE ALL THE LD50 DOSE (mg/kg) of the agents
Ethyl alcohol= 7060
Sodium Chloride= 3000
Naphthalene= 1760
Ferrous Sulfate= 1500
Aspirin= 1000
Formaldehyde= 800
Ammonia= 350
Dextromethorphan Hydrobromide= 350
Caffeine= 192
Phenobarbital= 150
Chlorpheniramine Maleate= 118
DDT= 100
Strychnine Sulfate = 2
Nicotine= 1
Dioxin= 0.0001
Botulinus Toxin= 0.00001
55
Enumerate all the Screening Tests (4)
1. Physical tests
2. Crystal tests
3. Chemical spot tests
4. Chromatography
56
Test for boiling point, melting point, density, and refractive index
Physical test
57
Test for treatment with a chemical reagent to produce crystals
Crystal tests
58
Test for treatment with a chemical reagent to produce color changes
Chemical spot tests
59
Test for (thin-layer or gas)--used to separate components of a mixture
Chromotography
60
Test toxicity for eyes
Draize test
61
Under measures of toxicity mortality means?
death
62
Under measures of toxicity teratogenicity means?
ability to cause birth defects
63
Under measures of toxicity carcinogenicity means?
ability to cause cancer
64
Under measures of toxicity mutagenicity means?
ability to cause heritable change in the DNA
65
The amount (dose) of a chemical which produces death in 50% of a population of test animals to which it is administered by any of a variety of methods
LD50
66
The concentration of a chemical in an environment (generally air or water) which produces death in 50% of an exposed population of test animals in a specified time frame
LC50
67
GIVE THE 4 CHEMICAL INTERACTIONS WITH EXAMPLES
* Additive 1+1=2
* Synergistic 1 +1>2
* Potentiation 1+0>1
* Antagonism 1+1<2
68
toxic chemicals affecting the same organ/system
Additive 1+1=2
69
toxic chemicals enhance each other's effects
Synergistic 1 +1>2
70
non-toxic chemical increases the toxic effect of a toxic chemical
Potentiation 1+0>1
71
chemicals hinder the toxic effect(s) of one another or both (le, antidote
Antagonism 1+1<2
72
EFFECTS OF TOXINS ON REPRODUCTION
1. Teratogenic
physical defects in embryo/fetus
mother is exposed but not necessarily affected
2. Mutagenesis
"mutate genes: permanent DNA changes
inheritable changes (future generations)
exposure to mother or father
usually also carcinogens
73
INFLUENCING FACTORS (7) CDRIIEC
Concentration
Duration and frequency of exposure
Route of entry
Interspecies variation
Intraspecies variation
Environmental factors
Chemical combinations
74
INTRASPECIES VARIATION
* Age and maturity
* Gender and hormonal status
* Genetic makeup
* State of health
74
3 WAYS OF PREVENTING ABSORPTION OF TOXICANTS
Gastric lavage
Induced Vomiting
Activated charcoal
75
Recommended for up to 2 hrs in TCA & up to 4hrs in Salicylate OD
Gastric lavage
76
Ipecac - Not routinely recommended and risk of aspiration
Induced Vomiting
77
Repetitive doses useful to enhance the elimination of certain drugs used in actiavted charcoal
theophylline, phenobarbital. carbamazepine, aspirin, sustained-release products (TPCAS)
78
Activated charcoal are not effective for.
cyanide, mineral acids, caustic alkalis, organic solvents, iron, ethanol, methanol poisoning, lithium
79
3 ways on ELIMINATION OF POISONS
1. Renal elimination
2. Forced alkaline diuresis
3. Hemodialysis or hemoperfusion
80
* Renal elimination
Medication to stimulate urination or defecation may be given to try to flush the excess drug out of the body faster.
81
* Forced alkaline diuresis
Infusion of large amount of NS+NAHCO3
Used to eliminate acidic drug that mainly excreted by the kidney eg salicylates
82
Hemodialysis or hemoperfusion
- Reserved for severe poisoning
83
Antidote for OPIATES
naloxone
84
MOA OF NALOXONE
Pure opioid antagonist competes and displaces narcotics at opioid receptor sites
85
S/E OF OPIATES
BP changes; arrythmias; seizures; withdrawal
86
Antidote for BENZODIAZEPINE
flumazenil
87
PHARMACOLOGY –TCAs
Presynaptic neurotransmitter reuptake
Cardiac fast sodium channels
Histamine (H1) receptors
CNS GABA-A receptors
88
TCAD OVERDOSE CLINICAL FEATURES
Arrhythmias (abnormal rhythm of heart rate)- widening of PR, QRS, and QT intervals; heart block; VF/VT
Hypotension (low BP)
Anticholinergic toxicity – hyperthermia (fever), flushing, dilated pupils, intestinal ileus, urinary retention, sinus tachycardia
Confusion, delirium, hallucinations
Seizures
89
TCAD OVERDOSE -TREATMENT
ABC-many require intubation
- Airway: palakaihin yung airway ng patient via incubation
- Breathing
- improve Circulation
Consider gastric lavage if taken < 2hrs
Activated charcoal
- The charcoal absorbs the toxins/ toxicity
Treatment of hypotension with isotonic saline
Sodium bicarbonate for cardiovascular toxicity
Alpha adrenergic vasopressors (norepinephrine) for hypotension refractory to aggressive fluid resuscitation and bicarbonate infusion
Benzodiazepines for seizures
90
Sodium bicarbonate is an high alert drug: T/F
TRUE
91
SPECIAL CAUTIONS IN TCAD OVERDOSE
Class IA and IC antiarrhythmic agents are contraindicated.
Magnesium may be useful
Flumazenil must not be given
92
DRUGS UNDER SALICYLATE OVERDOSE
Aspirin (acetylsalicylic acid)
Methyl salicylate (Oil of Wintergreen)
93
Fatal intoxication can occur IN TCAD overdose after the ingestion of ______ by adults and as little as _____ by children
10 to 30 g by adults and as little as 3 g by children
94
SALICYLATE OVERDOSE
Inhibition of cyclooxygenase
Stimulation of the chemoreceptor trigger zone
Activation of the respiratory center of the medulla
Uncoupled oxidative phosphorylation in the mitochondria
95
CLINICAL FEATURES in salicylate
o Early symptoms of aspirin toxicity include tinnitus, fever, vertigo, nausea, hyperventilation, vomiting, diarrhea
96
a condition that causes ringing or other noises in your ears
- Tinnitus
97
a condition where your blood has too little carbon dioxide due to rapid breathing
- Respiratory alkalosis
98
a condition in which acids build up in your body fluids
- Metabolic acidosis
99
measurement that tells you the acid levels in the blood
- Anion gap
100
SALICYLATE OVERDOSE – TREATMENT
>administration of sodium bicarbonate
>IV fluids +/- vasopressors
> Avoid intubation if at all possible
> Supplemental glucose
> Hemodialysis
101
What is N-ACETYLCYSTEINE
Antidote for paracetamol overdose
102
MOA of N-ACETYLCYSTEINE
a glutathione precursor & limits the formation and accumulation of NAPQI
103
Powerful anti-inflammatory and antioxidant effects
N-ACETYLCYSTEINE
104
measurement dose of N-ACETYLCYSTEINE
- 150mg/Kg over 15 min
- 50mg/Kg over next 4 hrs
- 100mg/kg over next 16 hrs. up to 36hrs
105
S/E OF N-ACETYLCYSTEINE
nausea, flushing, urticaria, bronchospasm, angioedema, fever, chills, hypotension, hemolysis and rarely, cardiovascular collapse
106
How many of acetaminophen is metabolized in the liver to sulfate and glucuronide conjugates that are then excreted in the urine ?
90%
107
____ of the remaining acetaminophen is excreted unchanged in the urine and ____ is metabolized via the hepatic ____ mixed function oxidase pathway to N-acetyl-p- benzoquinoneimine (NAPQI), which is hepatotoxic.
1. 1/2
2. 1/2
3. Cytochrome P450 (CYP2E1, CYP1A2, CYP3A4)
108
Drug that is widely available and potential toxicity underestimated
PARACETAMOL
109
DOSE MEASUREMENT OF NONTOXIC OF PARACCETAMOL
less than 150 mg/kg in child or 7.5 to 10 g for adult
110
DOSE MEASUREMENT OF TOXICICITY OF PARACCETAMOL
greater than 250 mg/kg or those greater than 12 g over a 24-hour period
111
PARACETAMOL OVERDOSE TREATMENT
Activated charcoal within four hours of ingestion
At the end of NAC infusion
Inhibits absorption of oral methionine
112
Mechanisms of Target Organ Toxicity and Agents Involved in Poisoning
Nervous system
1. central nervous system
2.peripheral nervous system
113
Central nervous system is made up of
brain and spinal cord
114
Peripheral nervous system of made up of
neurons (chemical agents that cause the release of chemical messenger)
115
Efferent division of PNS
- SOMATIC: Isa lang ang target organ, 1 neuron set up only
- AUTONOMIC: complicated, may 2 or more target organ, 2 neuron set up only. Nandito na yung synaptic cleft
116
Any adverse change in the structure or function of Nervous System during development or at maturity following exposure to a chemical, physical and biological agent
Neurotoxicity
117
Certain toxicants are specific for neurons, or sometimes a particular group of neurons, resulting in their injury or death
Neuropathies
118
Primary site of toxicity is the axon
Axonopathies
119
Myelin provides electrical insulation of neuronal processes, and its absence leads to a slowing of and/or aberrant conduction of impulse between adjacent processes, SO called ephaptic transmission
Myelopathies
120
Example of neuropathies
ANTICANCER AGENTS: vinca alkaloids, taxane derivatives, thalidomide
ANTIMICROBIALS: chloroquine, colistin, dapsone
CARDIOVASCULAR AGENTS: amiodarone, digoxin, statins
IMMUNOSUPPRESSANTS: interferons, leflunomide, penicillamine
MISCELLANEOUS AGENTS: cimetidine, phenytoin, lithium
121
Example of Axonopathies
Pyridinethion, compounds, Acrylamide, Gamma diketones.
122
Example of Myelopathies
Myelin, lead, hexachlorophene
123
Meaning of NAPQI?
N-acetyl-p-benzoquinone-imine
