paracetamol overdose + lithium Flashcards
(12 cards)
which groups are at increased risk of devloping hepatotoxicity following a paracetamol overdose
patients taking liver enzyme indicing drugs;
- rifampicin
- phenytoin
- carbamazepine
- chronic alcohol excess
- st johns wort
malnourished patients - anorexia/not eaten for days
acute alcohol intake effect on hepatotoxicity in paracetamol overdose
acute as opposed to chronci alcohol excess is NOT assoc with increased risk of developing hepatotoxicity
what mx can be given if paracetamol overdose patients present within 1hr
activated charcoal !!
- reduce absoption of drug
(minority of patients)
when should acetylcysteine be given
- staggered overdose (not all taken within an hour)
- patients who present 8-24hrs after
- patients who present >24hrs if clearly jaundiced/hepatic tenderness/big ALT
how quickly is acetylcysteine infused for paracetamol overdose
over 1hr
what adverse effect commonly occurs when giving acetylecysteine? how is this managed?
anaphlactoid reaction (non-IgE mediated mast cell release)
- stop infusion then restart at slower rate
criteria for liver transplant in paracetamol liver failure
pH <7.3, 24hrs after ingestion
or all of the following;
- prothrombin time >100secs
- creatinine >300
- grade III or Iv encephalopathy
what can lithium toxicity be precipitated by
dehydration
renal failure
drugs - thiazides, ACEi, ARBs, NSAIDs
metronidazole
where is lithium excreted
kidneys
key feature to distinguish between lithium toxicity + just therapeautic dose
toxicity = coarse tremor
therapeutic = Fine tremor
features of lithium toxicity
coarse tremor
hyperreflexia
acute confusion
seizure
coma
managmenet of lithium toxicity
mild-mod = IV fluid with isotonic saline
- monitor sodium (nephro DI)
severe = haemodialysis
