Serotonin syndrome and neuroleptic malignant syndrome Flashcards
What is the triad seen in serotonin syndrome?
Myoclonus/clonus
Altered mental state
Autonomic dysfunction
How soon do symptoms arise in SS?
Within 24 hours of increase in dose or addition of serotonergic agent
What groups of drugs can contribute to SS?
Amphetamines
Analgesics - fentanyl and tramadol
Buspirone
Lithium
MOAis
SSRIs
SNRIs
Serotonin 2A receptor blockers
St Johns wort
TCAs
anti-emetics - metoclopramide, ondansetron
Antimigraine drugs
Cocaine
Dextromethorphan
Linezolid
Tryptophans
What is treatment of SS?
Withdraw the cause
Supportive care
Control of agitation
5HT2A antagonist e.g. cyproheptadine
Mild - can have benzos
What are signs and symptoms of NMS
Fever
Diaphoresis
Rigidity
Confusion
Flutuating consciousness
Fluctuating blood pressure
Tachycardia
What can be seen in bloods in NMS
Elevated CK
Leukocytosis
Altered LFTs
What is the theory behind NMS?
Result of dopamine blockade at the hypothalamus which messes up the thermoregulatory system and results in hyperthermia
Calcium uptake into muscles results in muscle rigidity -> rhabdomyolysis and elevated CK
How quickly does NMS develop?>
Within 2 weeks of initial treatment but may occur at any time
What can cause NMS?
Antipsychotics
Valproate
Antidepressants
Phenytoin
Lithium
What is treatment of NMS?
Rehydration
Bromocriptine and dantrolene
Sedation with benzos
What is the mortality rate of NMS
5%
What are RFs for NMS
Younger age
Male
Psychosis and mental retardation
Psychomotor agitation
Dehydration
Previous NMS
Hyperthyroidism
Alcoholism
Parkinson’s disease
What might you consider when restarting antipsychotics after NMS
Stop APs for at least 5 days
Start with low dose and monitor closely
Consider antipsychotic structurally unrelated to the one associated with NMS
Consider drug with low dopamine affinity (quetiapine or clozapine)
Avoid depot
Avoid high potency FGA
What are RFs of NMS related to psychoactive medication ?
Recent or rapid antipsychotic dose increase or reduction
High potency antipsychotic use (FGAs)
Sudden withdrawal of anticholinergic agents
Antipsychotic polypharmacy
What are the main differences between presentation of NMS and SS?
SS - hyper-reflexia (often in the form of clonus, more marked in the lower extremities), ocular clonus and tremors in SS, whereas NMS is a bradykinetic syndrome characterised by uniform ‘lead-pipe’ rigidity and hyporeflexia.
