Toxicology (2) Flashcards
What is the antidote for benzodiazepine toxicity? MOA?
Flumazenil– competitive antagonist of BZD binding site at GABA A receptor
What is the duration of flumazenil’s clinical effects?
30-60 minutes
What are the antidotes used in organophosphate poisoning?
Atropine and pralidoxime (2-PAM)
What type of receptor does atropine act on in organophosphate poisoning?
Muscarinic receptors
What is the mechanism of action of pralidoxime (2-PAM)?
It is a cholinesterase-reactivating agent.
What is the antidote for atropine toxicity?
Physostigmine (for delirium and coma)
What is the preferred antidote for arsenic toxicity?
Freshly prepared hydrated ferric oxide
Toxin produced by spanish fly
Cantharidin
Causes blister formation and priapism
absorbed through skin and mucous membranes
Intermediate syndrome is seen in carbamate poisoning. (yes or no)
Yes
Reversible carbamylation wrt Carbamate poisoning
The rapid, spontaneous hydrolysis of the carbamate-cholinesterase bond, leading to regeneration of the enzyme within a few hours.
Why is the effect of carbamate toxicity of a shorter duration compared to organophosphate poisoning?
Due to reversible carbamylation, aging (conversion of the inhibited enzyme into a non-reactivable form- aging) does not occur.
Why is there less CNS toxicity in carbamate poisoning in adults?
Carbamates do not effectively penetrate the CNS in adults.
Why is pralidoxime contraindicated in carbamate poisoning?
It may potentiate the toxicity of carbamates due to its transient oxime-induced cholinesterase inhibition.
Magenstrasse
Pathway fluids take in food filled stomach along lesser curvature
If empty stomach, lower 2/3 is affected
Green colored urine is seen in
Carbolic acid poisoning– carboluria– d/t oxidation of hydroquinone and pyrecatechol on exposure to air
Carboluria will be f/b anuria
What are three sources of mercury exposure?
Thermometers (elemental mercury)
Industries (inorganic mercury)
Fish (organic mercury)
What is the primary route of absorption for elemental mercury?
Respiratory tract (negligible through GI unless mucosa is damaged).
What is the primary route of absorption for inorganic and organic mercury?
GIT
What is the mechanism of action for mercury toxicity?
Binds to sulfhydryl groups of enzymes and affects glutathione metabolism.
What organs are affected by acute organic mercury toxicity?
Respiratory and GI tracts
What organs are affected by chronic elemental mercury toxicity?
CNS and Renal
Mercury toxicity features
‘MEATS’
Mercuria lentis, Membranous colitis, Minimata d/s, Membranous glomerulopathy
Erethism (personality disturbance, insomnia, loss of memory)
Acrodynia (pink d/s)
Tremors– Danbury’s, Hatter’s, Glass blower’s shakes
Salivation (excess)
How is mercury poisoning diagnosed?
Blood and/or 24-hour urine mercury level
What are the treatments for mercury poisoning?
BAL (Dimercaprol) and Succimer (DMSA)
