Introduction To Poisoning Flashcards
a prompt and marked disturbance of function or death within a short time
Acute Poisoning
Acute Poisoning Conditions:
- Taking a strong poison
- Excessive single dose of a drug
- Several small doses but frequent administration of a drug
poisoning marked by a gradual deterioration of the function of tissues and may or may not result in death
Chronic Poisoning
Toxicity takes many months/years to become recognizable
Chronic Poisoning
Chronic Poisoning Conditions:
- Take several small doses of drugs at long intervals
- Taking only the toxic dose of a drug
Duration and Frequency of Exposure:
less than 24 hours-generally a single dose
Acute
Duration and Frequency of Exposure:
Repeated exposures- usually dietary
Acute
Duration and Frequency of Exposure:
Repeated exposure for a month or less
Subacute
Duration and Frequency of Exposure:
repeated exposure for 1 to 3 months
Subchronic exposure
Duration and Frequency of Exposure:
exposure for greater than three months
Chronic exposure
Acute Exposure of Benzene
CNS Narcosis
Chronic Exposure of Benzene
Bone Marrow Damage and Leukemia
Acute Exposure of Cigarette smoke
Nervous system stimulation
Chronic Exposure of Cigarette smoke
Cancer of mouth, pharynx, larynx, lung, esophagus, pancreas, bladder, and emphysema
Acute Exposure of Ethanol
headache, drowsiness, vomiting
Chronic Exposure of Ethanol
liver cirrhosis or liver cancer
an abnormal, undesirable, or harmful effect to the well-being that is indicated by some measurable endpoints
Adverse Effects
any noxious, unintended, and undesired effects of drugs that occur at normal doses; unpreventable
ADR (Adverse Drug Reaction)
an injury resulting from medical intervention related to the drug; medication error; preventable
ADE (Adverse Drug Event)
chromosomal breakage resulting in rearrangement of pieces of chromosomes
Clastogenesis
carries the genes, a combination of DNA, RNA, protein
chromosomes
The loss, addition, or rearrangement of chromosomes.
Clastogenesis
Can be associated with various chronic inflammatory disorders (Doxorubicin, Cisplatin)
Clastogenesis
Involve 2 different chromosomes wherein they exchanged places in location
Translocation
chemicals with molecular weights of less than 1000
Haptens
generally react with endogenous carrier molecules to become antigens before immunogenicity
Haptens
process by which the genetic information of an organism is changed, resulting in a mutation
Mutagenesis
Ex. Urushiol- poison ivy
Haptens
Ex. vinca alkaloid (vincristine, vinblastine), bromine, nicotine
Mutagenesis
refers to an injury produced by a chemical to one kind of living matter without harming some other kind, even though the two may have been an intimate contact
Selective Toxicity
study of malformations induced during development from conception to birth
Teratology
Teratogenic Substances - Thalidomide
phocomelia
Use of thalidomide before
morning sickness
Use of thalidomide now
Leprosy (Hansen’s diseases)
Teratogenic Substances - Phenytoin
fetal hydantoin syndrome
Teratogenic Substances - Vit. A
craniofacial dysmorphism;
can also lead to spontaneous abortion
Teratogenic Substances - Lithium
heart defect
Teratogenic Substances - ACEis
microcephaly, renal problem
Teratogenic Substances - Alcohol
fetal alcohol syndrome
synonymous with harmful in regard to the effects of chemicals
Toxic
relative term used in comparing one chemical with another
Toxicity
A relative property of a chemical referring to the harmful effects of the latter on some biologic mechanisms
Toxicity
expected frequency of a particular untoward effect in response to a particular agent
Risk
amount of exposure to a given agent that is deemed safe for a period of time
Threshold Limit Value (TLV)
determination of the ability of agents to produce tumors
Carcinogenicity /Tumorigenicity
quantity of medicine that can kill an organism
Lethal/Fatal Dose
Toxin in rotten corn
Aflatoxin
Toxicity associated with any chemical substance.
Intoxication
A clinical toxicity secondary to accidental exposure
Poisoning
An intentional exposure with the intent of causing self-injury or death.
Overdose
drugs that have almost exclusively harmful effects (no therapeutic effect whatsoever)
Poisons
Refers to toxic substances produced naturally
Toxin
Botulinum toxin
Clostridium botulinum
Botulinum toxin A
Botox
Tetanus toxin
Clostridium tetani
Corynebacterium diphtheriae
Diphtheria toxin
Bufo frog
Bufotoxin
Rosary pea
abrin
Rotten apple (aspergillus invade apple)
Patulin
Denotes the altered pharmacodynamics of a drug when given in toxic dosage, since normal receptors and mechanisms may be altered
Toxicodynamics
applied to the pharmacokinetics of toxic doses of chemicals, since the toxic effects of an agent may alter normal mechanisms for absorption, metabolism or excretion of a foreign material
Toxicokinetics
log dose that can produce 50% mortality in a population
LD50 or Median Lethal Dose
Dose that is required to kill half the members of a tested population after a specified test duration
LD50 or Median Lethal Dose
ability of a chemical agent to cause injury in a given situation or setting
hazard
are clinical syndromes that are essential for the successful recognition of poisoning patterns
Toxidromes
constellation of signs and symptoms that suggest a specific class of poisoning
toxidrome
The most important toxidromes,
clinically, are:
■ Sympathomimetic
■ Sedative Hypnotic
■ Opiate
■ Anticholinergic
■ Cholinergic
Examples of Sympathomimetic drugs
Epinephrine, norepinephrine, amphetamine, methamphetamine, caffeine
Examples of Sympathomimetic toxidromes
tachycardia, HTN, mydriasis, tremor, hallucination
Examples of Sedative hypnotic drugs
Barbiturates, Benzodiazepines
Examples of Opioid drugs
Morphine, codeine, heroine, oxycodone, fentanyl, methadone
Examples of Anticholinergic drugs
Atropine, scopolamine, antihistamine, benadryl
Examples of Cholinergic drugs
Organophosphates, carbamates, nerve gases
Examples of sedative hypnotic toxidromes
Sedation, CNS depression, confusion, blurred vision
Examples of opiate toxidromes
Pinpoint pupils (miosis)
Respiratory depression
Coma
Triad of Toxicity
Pinpoint pupils (miosis)
Respiratory depression
Coma
Examples of anticholinergic toxidromes
mydriasis, dryness, urinary retention
Examples of cholinergic toxidromes
■ Diarrhea
■ Urination
■ Miosis
■ Bradycardia
■ Bronchoconstriction
■ Emesis
■ Lacrimation
■ Salivation
■ Sweating
DUMBBELSS
■ Diarrhea
■ Urination
■ Miosis
■ Bradycardia nerve
■ Bronchoconstriction
■ Emesis
■ Lacrimation
■ Salivation
■ Sweating
Evidences contributed by circumstances. Deduced from various occurrences and facts.
Circumstantial or Moral Evidence
Includes symptoms observed during poisoning
Symptomatic Evidence
Examples: motives for poisoning purchasing the poison keeping the materials used
Circumstantial or Moral Evidence
Examples: arsenic poisoning is like cholera alcoholic coma may stimulate diabetic coma
Symptomatic Evidence
Evidence obtained by chemical analysis of the suspected substance, or the vomitus or secretion of the body
Chemical Evidence
This alone is not reliable because the poison may be decomposed or changed or it may have been placed anywhere after death.
Chemical Evidence
Evidence from examination of tissues and organs after death.
Post-mortem Evidence
After death evidence
Post-mortem Evidence
Obtained by administering the suspected substance to some living animal and noting the effects or symptoms.
Experimental Evidence
This is not a very conclusive procedure since tolerance may not be the same as in man.
Experimental Evidence
Major route of entry of poisons in the industrial setting.
Inhalation
Atmospheric pollutants gain entry mainly by ______
Inhalation
Ex. sulfur oxides, nitrogen oxides, carbon monoxide, and carbon dioxide. What route?
Inhalation
the lowest concentration of a certain odor compound that is perceivable the human sense of smell
Odor threshold
Route of exposure for water & soil pollutants
Oral ingestion
may occur in high concentrations or prolonged exposure to some substances
Olfactory fatigue
Hydrogen sulfide smell
Rotten egg
via GIT, the result of ingesting contaminated food or beverages, touching the mouth with contaminated fingers, or swallowing inhaled particles
Ingestion
Bypasses the protection provided by the intact skin and provides direct access in the bloodstream.
Injection
Most dangerous route of exposure
Injection
occur in hypersensitive individuals or after sensitization in allergic or sensitized persons
Allergic reactions
Reaction mediated by IgE
Allergic reactions
occurs when a person reacts to certain substances in the environment
Allergy
Often requires binding of chemical (hapten) to endogenous protein in order to be recognized by the immune system.
Allergic reactions
Reaction ranges from skin irritation to anaphylactic shock.
Allergic reactions
occur in individuals who have genetic polymorphisms that lead to structural changes in biomolecules, making them very sensitive or insensitive to a chemical
Idiosyncratic Reactions
Allergic reactions in skin ex:
itching, dermatitis, urticaria
A drug that causes prolonged muscle relaxation or short muscle relaxation (APNEA)
Succinylcholine
Most chemicals exert their effects soon after exposure.
IMMEDIATE toxicity
Immediate toxicity is mediated by Ig__
E
genetic tendency to develop allergic diseases
Atopy
acute allergic rxn to an antigen
Anaphylaxis
condition marked by spasm in the bronchi of lungs (bronchospasm)
Asthma
Delayed toxicity is mediated by ______
T-cells
Immediate toxicity is mediated by _____
IgE
Toxicity that may be delayed for days to years (cancer)
DELAYED toxicity
Organ/s that can regenerate itself
Liver
Organ/s that CANNOT regenerate itself
CNS (nerves)
Examples:
• Contact dermatitis
• TB - uses Mantoux Test
• Chronic Transplantation Rejection
• Multiple Sclerosis
DELAYED toxicity
Corrosives and irritants act locally
LOCAL toxicity
Little goes systemic
SYSTEMIC toxicity
affects specific site (site of absorption)
Local toxin
affects the entire body or many organs
Systemic toxin
Tetraethyl lead - CNS effect. This is an example of
Systemic toxicity
a drug has a major toxicity to one or two organs
Target organ
Target organ of lead
soft tissues of the brain
combined effect is the same as the sum of effects when given alone
Additive
1 + 1 = 2
Additive
● Alcohol + Benzodiazepine
Additive
Organophosphates + nerve gases
Additive
combined effects are much greater than the sum of effects when given alone
Synergistic
1 + 1 = 3
Synergistic
Pyrethroids + piperonyl butoxide(PBO)
Synergistic
● Carbon tetrachloride (hepatotoxic) + ethanol (hepatotoxic)
Synergistic
● Alcohol (hepatotoxic) + Acetaminophen (hepatotoxic)
Synergistic
exposure to a chemical with no toxicity increases the toxicity of another compound
Potentiation
1 + 0 = 2
Potentiation
● Isopropanol (no liver damage) + Carbon tetrachloride (causes liver damage)
Potentiation
co-administration of two chemicals interferes with the toxicity of both or one of them
Antagonism
1+1=0
Antagonism
Basis for antidotes
Antagonism
● Oral anticoagulants- Vit. K
● Venom - antivenom
● Alcohol overdose - caffeine
Antagonism
Type of antagonism:
Chemicals counterbalance each other by exerting opposite effects on a physiological function.
Functional
Type of antagonism:
chemical counterbalance affecting different receptors
Functional
Type of antagonism:
Chemical reaction between two compounds leads to less of the toxic compound.
Chemical (or inactivation)
e.g. Antivenins-An antitoxin active against the venom of a snake, spider, or other venomous animal or insect
Chemical (or inactivation)
An antitoxin active against the venom of a snake, spider, or other venomous animal or insect.
Antivenins
Via what reaction is done during chemical antagonism?
Neutralization
BAL means
British Anti-Lewisite
Type of antagonism:
Disposition of toxic chemical is changed so that concentration and/or duration is diminished.
Dispositional
Type of antagonism:
Chemicals compete for the same receptor, decreasing effective binding of toxic compound.
Receptor
Naloxone and morphine
Receptor antagonism (Competitive)
Tamoxifen and estradiol
Receptor Antagonism
DOC for breast cancer
Tamoxifen
Once a partial agonist is combined with a pure agonist, it automatically becomes _________
Antagonist
A state of decreased responsiveness due to a prior exposure to the same or a structurally similar chemical in an individual.
TOLERANCE
A decreased amount of chemical reaches the site where the effect is produced.
Dispositional Tolerance
Same amount of chemical reaches the site, but target receptor response decreased
Receptor Tolerance
Ability of the organism (bacteria, virus, fungi) to withstand the effects of drugs that are usually effective against them.
RESISTANCE
A change in the susceptibility to a chemical at the population level.
RESISTANCE
A selective process (evolution) by which sensitive individuals do not survive and only those with a genetic trait that accommodates the chemical survive.
RESISTANCE
