Serotonin Syndrome

Question 1

SS: Clinical features

Diagnosis is clinical & needs high index of suspicion

Answer 1

Mental Status changes
- apprehension
-anxiety
- agitation/ psychomotor acceleration
-delirium*
-confusion
Autonomic stimulation
-diarrhea *
flushing
-HTN
- hyperthermia
-mydriasis *
-sweating *
-Tachycardia *
Neuromuscular excitation
-clonus (ocular/ ankle)*
- hyperreflexia *
-increased tone LL > UL *
-Myoclonus *
- rigidity
-tremor

** significantly assoc with dx (hunter serotonin criteria)
onset within hrs
resolve 24-48 hrs

Question 2

SS- Complication

Answer 2

Rhabdomyolysis
Renal failure
DIC
Death

Question 3

SS may develop if

Answer 3

Increase in dose
Change in serotonergic drug without wash out
drug interaction
drug interaction with herbal preparation
deliberate self poisoning

Question 4

SS DDx

Answer 4

Neuroleptic malignant syndrome
anticholinergic syndrome
malignant hyperthermia
CNS infection
Salicylate toxicity
Theophylline toxicity
Nicotine
Sympathomimetic agent

Question 5

SS Mx

Answer 5

RESUS
ABC
Rx: 
-sz
-hyperthermia

IVaccess
Temp
BSL

Diazepam: 5-10mg 0.1-0.3 mg/kg/dose over 3-5 min
HTN: - GTN or nitroprusside
Risk assess 
Ix: CK, UEC, UEC, Trop
Supportive
-cease agent
-reassure
-IVFluid balance
- careful observation (temp/ bsl/ neuro/ muscle tone)
- Benzo

Question 6

SS antidote

Answer 6

1. Cyproheptadine:
   - PO or NG
   - 8 mg & continue q8hr as needed for 24 hrs
2. Chlorpromazine
   - 25-100 mg/ 100ml n-saline over 30-60 min)
3. Olanzapine
   - 10 mg SL

Question 7

Serotonergic drugs

Answer 7

Analgesic/ antitussives
- dextromethorphan
-fentanyl
-pethidine
-tramadol
Antidepressant
-TCA
Drugs of abuse
-Amphetamine
-MDMA
Lithium
St Johns wort
MAOI
-moclobomide
-phenelzine
SSRI
-citalopram
-escitalopram
-fluoxetine
-fluvoxamine
-paroxetine
-sertraline
SNRI
-Bupropion
-venlafaxine
Tryptophan