Serotonin syndrome and neuroleptic malignant syndrome Flashcards
Triad of symptoms seen in serotonin syndrome
Neuromuscular abnormalities - myoclonus, clonus
Altered mental state
Autonomic dysfunction
Time from starting or increasing a serotonergic drug to developing symptoms of serotonin syndrome
Within 24 hours
Vital signs seen in serotonin syndrome
HTN
Tachycardia
Tachypnoea
Hyperthermia >40 degrees
Neurological and psychiatric features of serotonin syndrome
Variable mental state - agitation to coma Increased muscle tone especially in legs Hyperreflexia Clonus Dilated pupils
Treatment for serotonin syndrome
Withdrawal of causative agent Supportive care 5HT2A antagonist e.g. cyproheptadine Benzodiazepines Atypical antipsychotics Paralysis and intubation in severe cases
Vital signs seen in neuroleptic malignant syndrome
HTN
Tachycardia
Tachypnoea
Hyperthermia >40 degrees
Neurological and behavioural features of neuroleptic malignant syndrome
Lead pipe rigidity in all limbs Confusion Fluctuating consciousness Hyporeflexia Normal pupils
GI feature of serotonin syndrome
Diarrhoea
High risk combinations for serotonin syndrome
SSRI and MAOI SSRI and RIMA SSRI and TCA SSRI and SNRI SSRI and lithium SSRI and l-tryptophan TCA and MAOI
Blood test results seen with neuroleptic malignant syndrome
Raised WCC
Raised CK
Deranged LFTs
Raised myoglobin
Proposed mechanisms causing neuroleptic malignant syndrome
Dopamine blockade at the hypothalamus causing hyperthermia
Calcium uptake into the muscles causing rigidity
Mortality rate for neuroleptic malignant syndrome
20%
Patient risk factors for developing neuroleptic malignant syndrome
Young age Male Psychosis Psychomotor retardation Intellectual disability Dehydration Previous NMS Hyperthyroidism Alcoholism Parkinson's disease
Drug related risk factors for developing neuroleptic malignant syndrome
Recent or rapid antipsychotic dose change
First generation antipsychotics
Sudden withdrawal of anticholinergic agents
Antipsychotic polypharmacy
Number of days antipsychotics should be stopped for following neuroleptic malignant syndrome
At least 5 days
Time frame neuroleptic malignant syndrome occurs in
Can occur at any time
Often 24-72 hours after a change in antipsychotic dose
Length of time neuroleptic malignant syndrome lasts if untreated
10-14 days
Treatments for neuroleptic malignant syndrome
Withdraw antipsychotic Benzodiazepines Rehydration Bromocriptine Dantrolene ECT - not generally used
Differences in time frames for serotonin syndrome and neuroleptic malignant syndrome
Serotonin syndrome has sudden onset over <12 hours; neuroleptic malignant syndrome has subacute onset over hours to days
Serotonin syndrome resolves within a day after the agent is stopped; neuroleptic malignant syndrome can take 1-2 weeks to resolve
Differences between serotonin syndrome and neuroleptic malignant syndrome in presence of myoclonus
Present in serotonin syndrome; not in neuroleptic malignant syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in presence of hypomania
Hypomania may be present in serotonin syndrome; not present in neuroleptic malignant syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in reflexes
Hyperreflexia in serotonin syndrome; normal reflexes or hyporeflexia in neuroleptic malignant syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in presence of rhabdomyolysis and resultant renal failure
Common in neuroleptic malignant syndrome; not present in serotonin syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in presence of WCC elevation
More common in neuroleptic malignant syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in pupils
Dilated in serotonin syndrome; normal in neuroleptic malignant syndrome
Differences between serotonin syndrome and neuroleptic malignant syndrome in bowel sounds
Increased in serotonin syndrome; normal or decreased in neuroleptic malignant syndrome
Medications which can cause serotonin syndrome
Antidepressants Lithium Opioids Olanzapine Risperidone
Incidence of neuroleptic malignant syndrome
0.07-0.2%
Time frame over which neuroleptic malignant syndrome develops
24-72 hours
Vitamin/mineral deficiency associated with increased risk of neuroleptic malignant syndrom
Low iron
