Toxicology Flashcards
What are the metal chelators?
EDTA, succimer
Define LD50
Lethal dose needed to produce death in 50% of those treated
Define LC50
Lethal concentration of a gas to produce death in 50% of patients
Define NOAEL
No observed adverse effect level. Highest dose that does not produce significant toxic effect.
Define RfD
Reference dose, estimate of daily exposure to an agent that is assumed tohave no adverse health impact
What does anticholinergic toxicity (atropine) look like? What is the treatment?
Tachycardia, dry hot skin, elevate temp, urinary retention, agitated delirium.
Treatment with physostigmine
What does sympathomimetic toxicity look like? What is the treatment?
Tachycardia, hypertension, elevated temp, diaphoresis, mydriasis, seizures, paranoia
Treatment IV benzodiazepine
Lidocaine for cocaine induced ventricular fib
What does opiate toxicity look like? What is the treatment?
Hypotension, bradycardia, coma, respiratory depression, miosis, hyporeflexia
Treatment is naloxone
What is the treatment for nonopiates?
Symptomatic treatment
Flumazenil for benzo
What are the signs of cholinergic toxicity? How is it treated?
Confusion, muscle twitching, salivation, weakness, urination
Atropine
Pralidoxime for organophosphates, nerve agents
This is a non specific chelator, limits drug absorption.
Activated charcoal
This is a non specific antidote useful for drug poorly absorbed by charcoal such as lithium.
Whole bowel irrigation with PEG 3350
Organophosphates act as what?
Acetylcholine esterase inhibitors
carbamates(physostigmine)
What are the signs and symptoms of organophosphate toxicity?
headache, nausea, dizziness, SLUD= salivation, lacrimation, urination, defication
What is the treatment for organophosphate toxicity?
Atropine.
2-PAM for non-carbmates
Where is methanol found?
Windshield washer solvent
What is the MoA of methanol?
metabolized to formaldehyde by ADH
cause blindness, metabolic acidosis
What is the treatment for methanol poisoning?
Fomepizole
Where is ethylene glycol found?
auto antifreeze
What is the MoA of ethylene glycol?
Metabolized to oxalic acid that had high affinity for calcium causing hypocalcemia, tetany. Crystal formation leads to renal injury.
What is the treatment for ethylene glycol poisoning?
Fomepizole
IV Ca, B vitamins
Where is diethylene glycol found?
improper pharmaceutical products
What are the signs of diethylene glycol poisoning?
Anuric renal failure, hepatitis, pancreatitis, nausea
What protein in the body acts as a chelator?
Metallothionein
What is the difference in halftimes for lead?
short in soft tissue
long (years) in bone
Inorganic common
What is the source of lead?
consuming contaminated food prepared in lead cooking utensils or canned food
Lead paint chips/dust inhalation,
drinking water
Hypochromic microcytic anemia, weak wrist/ankle, encephalopathy, colic are signs of?
Lead poisoning
What does lead do in the body?
inhibits hemoglobin synthesis resulting in anemia.
What is the treatment for lead poisoning?
Succimer, or EDTA
Dexamethasone for cerebral edema
What is childhood lead exposure associated with?
lower IQ, ADHD, aggressive behavoir
Which form of arsenic is more toxic? where is it found?
Inorganic forms.
Shrimp,shellfish, water supplies
Violent nausea, laryngitis, bronchitis, hemorrhagic gastroenteritis, garlic breath are signs of?
Arsenic poisoning
Hyperkeratosis, exfoliative dermatitis, vesicular lesions on feet are signs of chronic?
Arsenic poisoning
Which form of methylmercury is more toxic?
Organic are highly absorbed from GI tract and pass BBB.
Contaminated fish and grain fungicides
Cerebellar ataxia, movement disorders, deafness, loss of visual field are signs of?
Methylmercury poisoning
When are metal chelators used?
Only used in patients with highly elevated metal levels or severe toxicity.
This drug is given IV or IM for severe lead poisoning.
Calcium EDTA,
This drug is toxic to kidney at high dose. It can cause flu-like symptomes.
Calcium EDTA
This was the first orally effective metal chelator.
Succimer
more rapid than EDTA for lead and may also be used for mercury and arsenic
This is a colorless, odorless, tasteless, nonirritating and ubiquitous gas.
Carbon monoxide
What is the MoA of Carbon monoxide?
Out competes oxygen for binding sites on hemoglobin and forms carboxyhemoglobin.
Where is cyanide found?
Present in smoke (plastics, wool, metal plating)
Bitter almond breath, apnea, tachypnea, loss of consciousness are signs of?
Cyanide poisoning
How is cyanide poisoning treated?
Hydroxocobalamin
or Na nitrite
Where are PCBs and dioxin found?
Flame retardants, plasticizers, insulating material
Dermal acne-like eruptions called chloracne, nausea, headache, vomiting are signs of?
Dioxin poisoning
