Toxicology and Antidotes Flashcards
APAP overdose phases
phase 1: 1-24h, nausea and vomiting
phase 2: 24-48h inc INR, inc AST ALT, hepatotoxicity
phase 3: 48-96h, jaundice, coagulopathy, renal failure, possible death
phase 4: >96h, recovery or liver transplant
MDD of APAP
4,000mg (4g)
how does NAC work? how do we decide if it needs to be given?
NAC promotes conversion of the APAP toxic metabolite, NAPQI, to non-toxic products
APAP level is drawn 4-24 hours after ingestion
Rumack-Matthew nomogram uses [APAP] to determine NAC dose and appropriateness
how is PO NAC dosed
high dose x 1 then
low dose x17 doses
how is IV NAC dosed
3 infusions over 21 hours
what are the s/sx of anticholinergic overdose
blind as a bat: mydriasis, double or blurred vision
red as a beet: flushing
mad as a hatter: AMS
dry as a bone: dry skin and membranes
hot as a hare : fever
tx for anticholinergic overdose
pyridostigmine, an AchE inhibitor
apixaban or rivaroxaban reversal agent
Andexxa
pradaxa (dabigatran) reversal agent
Praxbind
warfarin reversal agent
vitamin K (phytonadione)
LMWH or UFH reversal agent
protamine
what reversal agent can be used for DOAC or warfarin reversal
PCC (Kcentra)
what treats dystonias in antipsychotic overdsoe
benztropine
how do we treat QRS widening in AP overdose
magnesium
benzo overdose tx
flumazenil
CCB overdose
glucagon and CaCl or Ca gluconate
cyanide/NTP toxicity treatment
hydroxocobalamin
or
sod thiosulfate + sod nitrite
digoxin toxicity
what is a normal level of dig
how do we treat overdose?
how much of the antidote covers digoxin?
max dose of antidote?
normal dig level 0.8-2.0 ng/mL for afib and 0.5-9 for HF
antidote = Digifab, comes in 40mg vials
1 vial Digifab = 40mg covers 0.5mg Digoxin
max Digifab dose = 20 vials
arsenic, gold, mercury poisoning antidote
dimercaprol
lead poisoning antidote
dimercaprol
+
CaNa2 EDTA
+
DMSA
thallium poisoning antidote
prussian blue
copper poisoning antidote
penicilamine
isoniazid overdose tx
B6 (pyridoxime)
iron overdose tx
deferoxamine
organophosphate toxicity tx
need to block Ach since OPs inhibit Ach breakdown
tx = atropine, an anticholinergic
+
pralidoxime (Protopam)
MTX overdose tx
leucovirin
salicylate overdose tx
salicylates are acids so tx OD w bicarb
treatment for toxic alcohol ingestion
(antifreeze/ethylene glycol, methanol)
fomepizole
TCA overdose tx
bicarb to narrow QRS
VPA overdose
what are wnl VPA levels
levocarnitine
wnl = 50-100
