Serotonergic v neuroleptic malignant syndrome Flashcards
What are 8 symptoms of poisoning by selective serotonin re-uptake inhibitors?
- Nausea + vomiting
- Agitation
- Tremor
- Nystagmus
- Drowsiness
- Sinus tachycardia
- Convulsions
- Serotonin syndrome - if severe (rare)
What are 6 possible effects of serotonin syndrome in severe SSRI poisoning?
- Neuropsychiatric effects
- Neuromuscular hyperactivity
- Autonomic nervous system excitation, incl. hyperthermia
- Rhabdomyolysis
- Renal failure
- Coagulopathies
What are 5 examples of causes of serotonin syndrome?
- Monoamine oxidase inhibitors
- SSRIs
- St John’s Wort - if taken with SSRIs can interact + cause
- Ecstasy
- Amphetamines
What is the management of serotonin syndrome? 4 aspects
- supportive management
- activated charcoal within first hour of overdose to reduce absorption
- treat convulsions with lorazepam/diazepam/midazolam
- if severe: serotonin antagonists e.g. cyproheptadine, chlorpromazine
What are 2 examples of serotonin antagonists which can be used in severe cases of serotonin syndrome?
- cyproheptadine
- chlorpromazine
Within what time frame of drug ingestion does serotonin syndrome occur?
within hours
What are 7 possible findings on examination in serotonin syndrome?
- Hyperreflexia
- Conus
- Dilated pupils
- Pyrexia
- Diaphoresis
- Tachycardia
- Hypertension
What is the cause of neuroleptic malignant syndrome?
rare but dangerous condition in patients taking antipsychotic medication - typical and atypical
In addition to antipsychotics what else can cause neuroleptic malignant syndrome?
dopaminergic drugs (e.g. levodopa) for Parkinso’s disease - when suddenly stopped or dose reduced
What is thought to be the pathophysiology behind neuroleptic malignant syndrome?
unknown, one theory is that dopamine blockade induced by antipsychotics triggers massive glutamate release and subsequent neurotoxicity and muscle damage
Within what time frame does neuroleptic malignant syndrome occur?
hours to days of starting antipsychotic
What are 7 possible clinical features of neuroleptic malignant syndrome?
- Pyrexia
- Muscle rigidity
- Autonomic lability: hypertension, tachycardia, tachypnoea
- Agitated delirium with confusion
- Hyporeflexia
- Lead-pipe rigidity
- Diaphoresis
What are 3 possible biochemical findings in neuroleptic malignant syndrome?
- Raised creatinine kinase
- Acute kidney injury - secondary to rhabdomyolysis
- Leucocytosis
What are 5 aspects of the management of neuroleptic malignant syndrome?
- Stop antipsychotic
- Transfer patient to medical ward if on psych ward
- often nursed in intensive care
- IV fluids to prevent renal failure
- Dantrolene in selected cases
- Bromocriptine (dopamine agonist) may be used
How is dantrolene thought to work in selected cases of neuroleptic malignant syndrome?
decreasing excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor, and decreasing release of calcium from the sarcoplasmic reticulum
