neuroleptic malignant syndrome Flashcards
what is NMS
rare
can kill
happens with antipsychotics
incidence in antipsychotic tx
0.1-0.2%
typical vs atypical?
atypical less incidence
incidence increasing?
no decreasing
mortality NMS?
20-38% but declining (
RFs NMS
- young men
- high dose
- organic mental prob + LD
- alcohol + substance abuse
- low iron
- +ve FhX
- high potency antipsychotics
- IM admin
- agitation/behavioural prob
- switch/discontinuation/restart
cause of NMS?
low dopamine = due to sudden and massive blockade of post synaptic dopamine receptors
pathophysiology NMS?
less dopamine in hypothalamus + diencephalon = hyperthermia, catatonia + autonomic dysfunction
less dopamine in BG = EPSEs
less dopamine in mesocortical regions = clouded consciousness
is it just dopamine in NMS?
nope also serotonin, glutamate, GABA
how long til NMS happens?
can happen after one dose
higher risk with depot
clozapine NMS?
less tremor and rigidity
core symptoms of NMS?
hyperthermia
altered consciousness
EPSE
ANS probs
typical natural hx of NMS?
- starts after 2wks
- worse over 24-72 hours
- subsides in 14 days
- goes if stop drugs
- longer course with depot
- catatonia underdiagnosed
diagnostic criteria/
T >38*C + muscle rigidity + any 2 of:
- diaphoresis
- dysphagia
- tremor
- incontinence
- altered consciousness
- mutism
- tachyC
- labile BP
- raised CK
- leucocytosis
scales of NMS?
hynes vicker scale
francis yakoub scale
ix for NMS?
CK - raised in most
leucocytosis
myoglobinuria - AKI
secondary features
what are the secondary features of NMS?
raised serum aldolase raised LDH raised transaminases hypoxia met acidosis low platelets DIC electrolyte probs deranged coag
tx for NMS
stop drug supportive dopamine agonist muscle relaxant benzos \+/- ECT
supportive measures?
- symptomatic management
- tx in emergency setting
- tx hyperthermia - improved outcome
- no physical restraint
- consider dialysis
dopamine agonists
- bromocriptine PO or NGT
others: levodopa, apomorphine, amantadine
dose bromocriptine?
60mg OD
caution bromocriptine?
- can worsen psychosis
- avoid in serotonin syndrome
- avoid if have used MAOIs prior to sx onset
muscle relaxant?
- dantrolene
- good for malignant hyperthermia
- IV
- don’t use alone
how does dantrolene work?
inhibits ionised ca++ release which causes muscle relaxation and less fever/rigidity
benzos in NMS?
lorazepam
diazepam
GABA-mimetic + increase dopaminergic function in BG
control agitation
anticholinergics in NMs
NO as they inhibit sweating and worsen it
ECT in NMS?
effective, safe
esp if affective or catatonic components
px
- COD often from cardiac or resp arrest
- hypertheria >39.5 is poor px
- DIC is ominous
