Serotonin syndrome: Difference between revisions
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==Background== | ==Background== | ||
*Can be produced by any serotonergic medication | *Can be produced by any serotonergic medication | ||
* | *1 in 6 U.S. adults take at least one psychoactive medication<ref>Moore TJ and Mattison DR. Adult Utilization of Psychiatric Drugs and Differences by Sex, Age, and Race. JAMA Intern Med. Published online December 12, 2016. doi:10.1001/jamainternmed.2016.7507.</ref> | ||
*Majority of cases occur within therapeutic drug dosages | |||
*Most common cause is ingestion of foods high in L-Tryptophan while taking an MAOI. Second most common is ingestion of both SSRI and MAOI<ref>Stork CM. Serotonin Reuptake Inhibitors and Atypical Antidepressants. In: Flomenbaum N, Goldfrank L, Hoffman R, Howland MA, et al, eds. Goldfrank’s Toxicologic Emergencies. 8th Ed. New York, NY: McGraw-Hill; 2006: 1070-1082</ref> | |||
*Most common cause of death is severe hyperthermia | *Most common cause of death is severe hyperthermia | ||
==Causative Agents<ref>Brown CH. Drug-induced Serotonin Syndrome. US Pharm. 2010;35(11):HS-16-HS-21.</ref>== | |||
===Antidepressants=== | |||
*[[SSRIs]] | *[[SSRIs]] | ||
*MAOIs | *[[SNRIs]] | ||
* | *[[Buspirone]] | ||
*Drugs of Abuse | *[[TCAs]] | ||
*Analgesics | *[[Lithium]] | ||
*Antiemetics | *[[Mirtazapine]] | ||
*[[Trazodone]] | |||
*[[Valproic acid]] | |||
*MAOIs (should have washout period of 2+ weeks prior to starting a SSRI) | |||
**Phenelzine | |||
**Selegiline | |||
**Tranylcypromine | |||
===Drugs of Abuse=== | |||
*[[Cocaine]] | |||
*[[Ecstasy (MDMA)]] | |||
*[[Methamphetamine]] | |||
*[[LSD]] | |||
===Analgesics=== | |||
*[[Fentanyl]] | |||
*[[Meperidine]] (Demerol) | |||
*[[Methadone]] | |||
*[[Tramadol]] | |||
===[[Antiemetics]]=== | |||
*[[Metoclopramide]] | |||
*[[Ondansetron]] | |||
===Over the counter Medications=== | |||
*[[Dextromethorphan]] | |||
*Oral decongestants ([[Pseudoephedrine]]) | |||
===Herbal products=== | |||
*St John’s Wort, Ginseng, Nutmeg, Yohimbe | |||
===Other Medications=== | |||
*Triptans | *Triptans | ||
*Ergot alkaloids | |||
*Bromocriptine | *Bromocriptine | ||
* | *[[Linezolid]] | ||
*[[Carbamazepine]] | |||
*[[Cyclobenzaprine]] | |||
*L-tryptophan, 5-hydroxytryptophan | |||
*[[Methylene blue]] | |||
==Clinical Features== | ==Clinical Features== | ||
*[[Altered mental status]]: Agitated delirium | *[[Altered mental status]]: Agitated delirium. Patients generally hyperactive. | ||
*Autonomic Instability: Hyperthermia, | *Autonomic Instability: Hyperthermia, tachycardia, hypertension, diaphoresis, gastrointestinal illness <ref>Boyer, E. W. and Shannon, M. (2005) ‘The Serotonin Syndrome’, New England Journal of Medicine, 352(11), pp. 1112–1120. doi: 10.1056/nejmra041867</ref> | ||
**Often labile blood pressure, HR | **Often labile blood pressure, HR | ||
*Neuromuscular Abnormalities: Myoclonus, ocular clonus, rigidity, hyperreflexia, tremor | *Neuromuscular Abnormalities: Myoclonus, ocular clonus, rigidity, hyperreflexia, tremor, seizures | ||
**More pronounced in the lower extremities | **More pronounced in the lower extremities | ||
**Myoclonus: most common finding | **Myoclonus (inducible or spontaneous): most common finding | ||
***Important to identify because it does not occur in other conditions that mimic serotonin syndrome | ***Important to identify because it does not occur in other conditions that mimic serotonin syndrome | ||
**Hyperactivity as opposed to rigidity in [[neuroleptic malignant syndrome]] | |||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
{{AMS and fever DDX}} | {{AMS and fever DDX}} | ||
== | ==Evaluation== | ||
===Hunter Toxicity Criteria Decision Rules=== | ===Hunter Toxicity Criteria Decision Rules=== | ||
Serotonergic agent plus 1 of the following<ref>Dunkley EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM 2003;96:635-642</ref>: | Serotonergic agent plus 1 of the following<ref>Dunkley EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM 2003;96:635-642</ref>: | ||
Line 34: | Line 70: | ||
*Ocular Clonus AND (agitation or diaphoresis) | *Ocular Clonus AND (agitation or diaphoresis) | ||
*Tremor AND hyperreflexia | *Tremor AND hyperreflexia | ||
*Hypertonia AND | *Hypertonia AND temperature >38 AND (ocular clonus or inducible clonus) | ||
''84% Sn, 97% Sp'' | ''84% Sn, 97% Sp'' | ||
{{Serotonin syndrome vs neuroleptic malignant syndrome}} | |||
==Management== | ==Management== | ||
*Discontinue all serotonergic drugs | *Discontinue all serotonergic drugs | ||
*Aggressive supportive care | *Aggressive supportive care | ||
**If pressors required, direct acting (e.g. | **If pressors required, direct acting (e.g. norepinephrine, epi) preferred, MAO inhibition causes erratic response to dopamine | ||
*[[Benzos]] | *[[Benzos]] | ||
**Goal is to eliminate agitation, neuromuscular abnormalities, elevations in HR/BP | **Goal is to eliminate agitation, neuromuscular abnormalities, elevations in HR/BP | ||
**In severe cases, large doses are required (diazepam IV 10-20 mg, titrated with 10 mg increments) | |||
*[[Cyproheptadine]]<ref>Graudins, A., Stearman, A. and Chan, B. (1998) ‘Treatment of the serotonin syndrome with cyproheptadine’, The Journal of Emergency Medicine, 16(4), pp. 615–619. doi: 10.1016/s0736-4679(98)00057-2</ref> | *[[Cyproheptadine]]<ref>Graudins, A., Stearman, A. and Chan, B. (1998) ‘Treatment of the serotonin syndrome with cyproheptadine’, The Journal of Emergency Medicine, 16(4), pp. 615–619. doi: 10.1016/s0736-4679(98)00057-2</ref> | ||
**Give if | **Give if benzodiazepines and supportive care fail to improve agitation and abnormal vitals | ||
**Serotonin antagonist | **Serotonin antagonist | ||
***Also has antihistamine and anticholinergic properties that may exacerbate other mixed toxicology picture | |||
**Give 12mg PO/NG; repeat with 2mg q2hr until clinical response is seen (max 32mg/d) | **Give 12mg PO/NG; repeat with 2mg q2hr until clinical response is seen (max 32mg/d) | ||
**Give 4mg q6hr x48hr if | **Give 4mg q6hr x48hr if patient is responsive to initial dose | ||
*[[Chlorpromazine]]<ref>Gillman PK. The serotonin syndrome and its treatment. J Psychopharmacol 1999;13:100-109</ref> | *[[Chlorpromazine]]<ref>Gillman PK. The serotonin syndrome and its treatment. J Psychopharmacol 1999;13:100-109</ref> | ||
**Phenothiazine with antiserotonergic effects | **Phenothiazine with antiserotonergic effects | ||
**50mg to 100mg IM | **50mg to 100mg IM | ||
**Can | **Avoid in: | ||
*[[Dexmedetomidine]]<ref>Rushton WF, Charlton NP. Dexmedetomidine in the treatment of serotonin syndrome. Ann Pharmacother. 2014; 48(12):1651-1654.</ref> | ***Hemodynamically unstable patients as can cause serious hypotension<ref>Frank C. Recognition and treatment of serotonin syndrome. Can Fam Physician. 2008 Jul; 54(7): 988–992.</ref> | ||
***Cases in which NMS may still be on the differential | |||
*[[Dexmedetomidine]]<ref>Rushton WF, Charlton NP. Dexmedetomidine in the treatment of serotonin syndrome. Ann Pharmacother. 2014; 48(12):1651-1654.</ref><ref>Duggal HS, Fetchko J. Serotonin syndrome and atypical antipsychotics. Am J Psychiatry. 2002;159(4):672–3.</ref> | |||
**Small case series found this helpful in adolescent cases refractory to benzos | **Small case series found this helpful in adolescent cases refractory to benzos | ||
*Dantrolene generally not recommended as it can worsen serotonin toxicity<ref>Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005 Mar 17; 352(11):1112-20.</ref> | |||
*Treat hyperthermia | *Treat hyperthermia | ||
**Hyperthermia due to increase in muscular activity, not change in set point | **Hyperthermia due to increase in muscular activity, not change in set point | ||
**[[Intubate]] and paralyze if | **[[Intubate]] and paralyze if temperature > 41.1 | ||
**Standard [[cooling measures]] | **Standard [[cooling measures]] | ||
==Disposition== | ==Disposition== | ||
* | *Severe cases may require [[intubation]] and [[ventilation]] in ICU | ||
*24hr admission for | *24hr admission for [[altered mental status]] or abnormal [[vital signs]] requiring further supportive care | ||
* | *Discharge mild cases with minimal intervention required after 6 hrs of observation | ||
==See Also== | ==See Also== | ||
*[[Toxidromes]] | *[[Toxidromes]] | ||
==Video== | |||
{{#widget:YouTube|id=nicowGCfm30}} | |||
==References== | ==References== | ||
<references/> | <references/> | ||
[[Category: | [[Category:Toxicology]] |
Revision as of 21:07, 27 November 2019
Background
- Can be produced by any serotonergic medication
- 1 in 6 U.S. adults take at least one psychoactive medication[1]
- Majority of cases occur within therapeutic drug dosages
- Most common cause is ingestion of foods high in L-Tryptophan while taking an MAOI. Second most common is ingestion of both SSRI and MAOI[2]
- Most common cause of death is severe hyperthermia
Causative Agents[3]
Antidepressants
- SSRIs
- SNRIs
- Buspirone
- TCAs
- Lithium
- Mirtazapine
- Trazodone
- Valproic acid
- MAOIs (should have washout period of 2+ weeks prior to starting a SSRI)
- Phenelzine
- Selegiline
- Tranylcypromine
Drugs of Abuse
Analgesics
- Fentanyl
- Meperidine (Demerol)
- Methadone
- Tramadol
Antiemetics
Over the counter Medications
- Dextromethorphan
- Oral decongestants (Pseudoephedrine)
Herbal products
- St John’s Wort, Ginseng, Nutmeg, Yohimbe
Other Medications
- Triptans
- Ergot alkaloids
- Bromocriptine
- Linezolid
- Carbamazepine
- Cyclobenzaprine
- L-tryptophan, 5-hydroxytryptophan
- Methylene blue
Clinical Features
- Altered mental status: Agitated delirium. Patients generally hyperactive.
- Autonomic Instability: Hyperthermia, tachycardia, hypertension, diaphoresis, gastrointestinal illness [4]
- Often labile blood pressure, HR
- Neuromuscular Abnormalities: Myoclonus, ocular clonus, rigidity, hyperreflexia, tremor, seizures
- More pronounced in the lower extremities
- Myoclonus (inducible or spontaneous): most common finding
- Important to identify because it does not occur in other conditions that mimic serotonin syndrome
- Hyperactivity as opposed to rigidity in neuroleptic malignant syndrome
Differential Diagnosis
Altered mental status and fever
- Infectious
- Sepsis
- Meningitis
- Encephalitis
- Cerebral malaria
- Brain abscess
- Other
Evaluation
Hunter Toxicity Criteria Decision Rules
Serotonergic agent plus 1 of the following[5]:
- Spontaneous clonus
- Inducible clonus AND (agitation or diaphoresis)
- Ocular Clonus AND (agitation or diaphoresis)
- Tremor AND hyperreflexia
- Hypertonia AND temperature >38 AND (ocular clonus or inducible clonus)
84% Sn, 97% Sp
Serotonin syndrome vs Neuroleptic malignant syndrome
- History of a new serotonergic drug or a dose increase of a serotonergic drug are helpful
- Serotonin syndrome is usually much more acute in onset than NMS which may develop over days or weeks
- Presence of ‘lead pipe’ rigidity is typical of NMS, while serotonin syndrome typically manifests with tremor and hyperreflexia
- Elevations in CK, LFTs, and WBC, coupled with a low iron level, distinguishes NMS from serotonin syndrome among patients taking both neuroleptic and serotonin agonist medications simultaneously
Management
- Discontinue all serotonergic drugs
- Aggressive supportive care
- If pressors required, direct acting (e.g. norepinephrine, epi) preferred, MAO inhibition causes erratic response to dopamine
- Benzos
- Goal is to eliminate agitation, neuromuscular abnormalities, elevations in HR/BP
- In severe cases, large doses are required (diazepam IV 10-20 mg, titrated with 10 mg increments)
- Cyproheptadine[6]
- Give if benzodiazepines and supportive care fail to improve agitation and abnormal vitals
- Serotonin antagonist
- Also has antihistamine and anticholinergic properties that may exacerbate other mixed toxicology picture
- Give 12mg PO/NG; repeat with 2mg q2hr until clinical response is seen (max 32mg/d)
- Give 4mg q6hr x48hr if patient is responsive to initial dose
- Chlorpromazine[7]
- Phenothiazine with antiserotonergic effects
- 50mg to 100mg IM
- Avoid in:
- Hemodynamically unstable patients as can cause serious hypotension[8]
- Cases in which NMS may still be on the differential
- Dexmedetomidine[9][10]
- Small case series found this helpful in adolescent cases refractory to benzos
- Dantrolene generally not recommended as it can worsen serotonin toxicity[11]
- Treat hyperthermia
- Hyperthermia due to increase in muscular activity, not change in set point
- Intubate and paralyze if temperature > 41.1
- Standard cooling measures
Disposition
- Severe cases may require intubation and ventilation in ICU
- 24hr admission for altered mental status or abnormal vital signs requiring further supportive care
- Discharge mild cases with minimal intervention required after 6 hrs of observation
See Also
Video
{{#widget:YouTube|id=nicowGCfm30}}
References
- ↑ Moore TJ and Mattison DR. Adult Utilization of Psychiatric Drugs and Differences by Sex, Age, and Race. JAMA Intern Med. Published online December 12, 2016. doi:10.1001/jamainternmed.2016.7507.
- ↑ Stork CM. Serotonin Reuptake Inhibitors and Atypical Antidepressants. In: Flomenbaum N, Goldfrank L, Hoffman R, Howland MA, et al, eds. Goldfrank’s Toxicologic Emergencies. 8th Ed. New York, NY: McGraw-Hill; 2006: 1070-1082
- ↑ Brown CH. Drug-induced Serotonin Syndrome. US Pharm. 2010;35(11):HS-16-HS-21.
- ↑ Boyer, E. W. and Shannon, M. (2005) ‘The Serotonin Syndrome’, New England Journal of Medicine, 352(11), pp. 1112–1120. doi: 10.1056/nejmra041867
- ↑ Dunkley EJ, Isbister GK, Sibbritt D, Dawson AH, Whyte IM. The Hunter Serotonin Toxicity Criteria: simple and accurate diagnostic decision rules for serotonin toxicity. QJM 2003;96:635-642
- ↑ Graudins, A., Stearman, A. and Chan, B. (1998) ‘Treatment of the serotonin syndrome with cyproheptadine’, The Journal of Emergency Medicine, 16(4), pp. 615–619. doi: 10.1016/s0736-4679(98)00057-2
- ↑ Gillman PK. The serotonin syndrome and its treatment. J Psychopharmacol 1999;13:100-109
- ↑ Frank C. Recognition and treatment of serotonin syndrome. Can Fam Physician. 2008 Jul; 54(7): 988–992.
- ↑ Rushton WF, Charlton NP. Dexmedetomidine in the treatment of serotonin syndrome. Ann Pharmacother. 2014; 48(12):1651-1654.
- ↑ Duggal HS, Fetchko J. Serotonin syndrome and atypical antipsychotics. Am J Psychiatry. 2002;159(4):672–3.
- ↑ Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005 Mar 17; 352(11):1112-20.