Principles of Clinical Toxicology and Treatment of Acute Poisoning Flashcards
ED50
Effective dose: concentration that produces half of the maximum effect
LD50
Dose that kills half of the subjects exposed
TD50
Dose that produces the half maximum toxicity
Therapeutic index
LD50/ED50
Threshold (non-toxic) dose)
No observed adverse effects below this line
Carcinogenesis
Metabolically activated: Aromatic amines, nitrosamies, PAHs, Aflatoxin
Alkylating agents: cyclophosphamide, melphalan
Teratogenicity Category A
Animal negative/human negative
SAFE
Teratogenicity Category B
Animal negative/human not available OR animal adverse/human negative
Presumed to be safe
Teratogenicity Category C
Animal adverse/human not available OR animal and human not available
Give only if potential benefit justifies risk
Dangerous in 1st trimester
Teratogenicity Category D
Human risk, but benefits to mom may be acceptable in a life threatening/serious disorder
Teratogenicity Category X
Risk of the drug clearly outweighs possible benefit
Contraindicated in women who are or who may become pregnant
Cholinergic or anticholinesterase syndrome- MOA
Organophosphate and carbamate insecticides > inhibition of cholinesterase and accumulation of acetylcholine
Cholinergic or anticholinesterase syndrome symptoms
Muscarinic: sweating, miosis, lacrimation, abdominal cramps, vomiting, diarrhea, bradycardia, hypotension
Nicotinic: Fasiculations, cramps, weakness, paralysis, respiratory compromise
Central: Anxiety, restlessness, coma
Cholinergic or anticholinesterase syndrome treatment
Atropine
Anticholinergic Syndrome MOA
Atropine, scopolamine, tricyclic antidepressants, antihistamines, jimson weed
Too little acetylcholine at the muscarinic receptor site
Anticholinergic Syndrome SE
dry mouth, dysphagia, mydriasis, tachycardia, hyperthermia, dry skin, flushing, lethargy, seizures, confusion, respiratory failure
Anticholinergic Syndrome Treatment
Physostigmine
Hemoglobinopathy Syndromes
Carboxyhemoglobinemia (CO)
Methemoglobinemia (sulfonamides)
Hypoxia, headache, disorientation, cardiac dysfunction, acidosis, death
Narcotic Overdose MOA
Heroin, oxycodone, Morphine, Meperidine
Narcotic Overdose Symptoms
respiratory depression, hypotension, pinpoint pupils
Sympathomimetic excess MOA
Cocaine, amphetamines, MAOIs > too much NE
Sympathomimetic excess symptoms
Diaphoresis/dehydration, nervousness, tremor, CNS excitation, hypertension, tachycardia, seizures
Withdrawal syndrome (opiate vs. non-opiate symptoms)
Opiate withdrawal: mydriasis, piloerection, rhinorrhea, lacrimation (no seizures)
NON-opiate CNS depressants: hallucinations, tachycardia, hyperpyrexia, SEIZURES
Cardiac conduction/rhythm problems (AV block, brady, tachy)
AV block: digitalis
Sinus brady: digitalis, beta-blockers, ca channel blockers
Sinus tachy: cocaine, amphetamines
Metabolic acidosis
Aspirin, methanol and ethylene glycol
GI dysfunction
Cholinergic syndrome: cramping, n/v
Iron poisoning: bloody diarrhea
Seizures cause
Intoxication, withdrawal
Seizure treatment
Diazepam/lorazepam: acute control
Phenobarbital: long term
Antidotes: Iron- Acetaminophen- Organophosphate- Anticholinergic- Methanol and ethylene glycol- Digitalis-
Iron- Deferoxamine Acetaminophen- Acetylcystine Organophosphate- 2-PAM or atropine Anticholinergic- Physostigmine Methanol and ethylene glycol- Ethanol Digitalis- Digitalis Antibodies
Indications for elimination of absorbed substances
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
