Principles of Clinical Toxicology and Treatment of Acute Poisoning

Question 1

ED50

Answer 1

Effective dose: concentration that produces half of the maximum effect

Question 2

LD50

Answer 2

Dose that kills half of the subjects exposed

Question 3

TD50

Answer 3

Dose that produces the half maximum toxicity

Question 4

Therapeutic index

Answer 4

LD50/ED50

Question 5

Threshold (non-toxic) dose)

Answer 5

No observed adverse effects below this line

Question 6

Carcinogenesis

Answer 6

Metabolically activated: Aromatic amines, nitrosamies, PAHs, Aflatoxin
Alkylating agents: cyclophosphamide, melphalan

Question 7

Teratogenicity Category A

Answer 7

Animal negative/human negative

SAFE

Question 8

Teratogenicity Category B

Answer 8

Animal negative/human not available OR animal adverse/human negative
Presumed to be safe

Question 9

Teratogenicity Category C

Answer 9

Animal adverse/human not available OR animal and human not available
Give only if potential benefit justifies risk
Dangerous in 1st trimester

Question 10

Teratogenicity Category D

Answer 10

Human risk, but benefits to mom may be acceptable in a life threatening/serious disorder

Question 11

Teratogenicity Category X

Answer 11

Risk of the drug clearly outweighs possible benefit

Contraindicated in women who are or who may become pregnant

Question 12

Cholinergic or anticholinesterase syndrome- MOA

Answer 12

Organophosphate and carbamate insecticides > inhibition of cholinesterase and accumulation of acetylcholine

Question 13

Cholinergic or anticholinesterase syndrome symptoms

Answer 13

Muscarinic: sweating, miosis, lacrimation, abdominal cramps, vomiting, diarrhea, bradycardia, hypotension
Nicotinic: Fasiculations, cramps, weakness, paralysis, respiratory compromise
Central: Anxiety, restlessness, coma

Question 14

Cholinergic or anticholinesterase syndrome treatment

Answer 14

Atropine

Question 15

Anticholinergic Syndrome MOA

Answer 15

Atropine, scopolamine, tricyclic antidepressants, antihistamines, jimson weed
Too little acetylcholine at the muscarinic receptor site

Question 16

Anticholinergic Syndrome SE

Answer 16

dry mouth, dysphagia, mydriasis, tachycardia, hyperthermia, dry skin, flushing, lethargy, seizures, confusion, respiratory failure

Question 17

Anticholinergic Syndrome Treatment

Answer 17

Physostigmine

Question 18

Hemoglobinopathy Syndromes

Answer 18

Carboxyhemoglobinemia (CO)
Methemoglobinemia (sulfonamides)
Hypoxia, headache, disorientation, cardiac dysfunction, acidosis, death

Question 19

Narcotic Overdose MOA

Answer 19

Heroin, oxycodone, Morphine, Meperidine

Question 20

Narcotic Overdose Symptoms

Answer 20

respiratory depression, hypotension, pinpoint pupils

Question 21

Sympathomimetic excess MOA

Answer 21

Cocaine, amphetamines, MAOIs > too much NE

Question 22

Sympathomimetic excess symptoms

Answer 22

Diaphoresis/dehydration, nervousness, tremor, CNS excitation, hypertension, tachycardia, seizures

Question 23

Withdrawal syndrome (opiate vs. non-opiate symptoms)

Answer 23

Opiate withdrawal: mydriasis, piloerection, rhinorrhea, lacrimation (no seizures)
NON-opiate CNS depressants: hallucinations, tachycardia, hyperpyrexia, SEIZURES

Question 24

Cardiac conduction/rhythm problems (AV block, brady, tachy)

Answer 24

AV block: digitalis
Sinus brady: digitalis, beta-blockers, ca channel blockers
Sinus tachy: cocaine, amphetamines

Question 25

Metabolic acidosis

Answer 25

Aspirin, methanol and ethylene glycol

Question 26

GI dysfunction

Answer 26

Cholinergic syndrome: cramping, n/v | Iron poisoning: bloody diarrhea

Question 27

Seizures cause

Answer 27

Intoxication, withdrawal

Question 28

Seizure treatment

Answer 28

Diazepam/lorazepam: acute control | Phenobarbital: long term

Question 29

``` Antidotes: Iron- Acetaminophen- Organophosphate- Anticholinergic- Methanol and ethylene glycol- Digitalis- ```

Answer 29

``` Iron- Deferoxamine Acetaminophen- Acetylcystine Organophosphate- 2-PAM or atropine Anticholinergic- Physostigmine Methanol and ethylene glycol- Ethanol Digitalis- Digitalis Antibodies ```

Question 30

Indications for elimination of absorbed substances

Answer 30

Severe poisoning that does not respond to supportive therapy Deterioration despite full supportive care Overwhelming dose of a chemical Impairment of normal excretory routes Severe disease that precludes tolerance of supportive care