Serotonin syndrome

Summary

Serotonin syndrome (MONDO:0018546) is a disease and 3 clinical trials. Top therapeutic interventions include cyproheptadine. A subtype of nervous system disorder — broader associated-gene and molecular evidence is on the parent page (see Disease family below).

At a glance

• Prevalence: Unknown (Worldwide) [Orphanet-validated]
• Phenotypes (HPO): 34
• Clinical trials: 3

Clinical features

Signs & symptoms

Clinical features (HPO)

34 HPO clinical features (Orphanet curated; top 34 by frequency):

HPO ID	Term	Frequency
HP:0002270	Abnormality of the autonomic nervous system	Very frequent (80-99%)
HP:0000711	Restlessness	Frequent (30-79%)
HP:0000737	Irritability	Frequent (30-79%)
HP:0000739	Anxiety	Frequent (30-79%)
HP:0001268	Mental deterioration	Frequent (30-79%)
HP:0001289	Confusion	Frequent (30-79%)
HP:0001336	Myoclonus	Frequent (30-79%)
HP:0001337	Tremor	Frequent (30-79%)
HP:0001649	Tachycardia	Frequent (30-79%)
HP:0002014	Diarrhea	Frequent (30-79%)
HP:0002018	Nausea	Frequent (30-79%)
HP:0100785	Insomnia	Frequent (30-79%)
HP:0000570	Abnormal saccadic eye movements	Occasional (5-29%)
HP:0000713	Agitation	Occasional (5-29%)
HP:0000822	Hypertension	Occasional (5-29%)
HP:0000975	Hyperhidrosis	Occasional (5-29%)
HP:0001250	Seizure	Occasional (5-29%)
HP:0001347	Hyperreflexia	Occasional (5-29%)
HP:0002169	Clonus	Occasional (5-29%)
HP:0002789	Tachypnea	Occasional (5-29%)
HP:0003128	Lactic acidosis	Occasional (5-29%)
HP:0011499	Mydriasis	Occasional (5-29%)
HP:0032044	Decreased vigilance	Occasional (5-29%)
HP:0000738	Hallucinations	Very rare (<1-4%)
HP:0001259	Coma	Very rare (<1-4%)
HP:0001276	Hypertonia	Very rare (<1-4%)
HP:0001399	Hepatic failure	Very rare (<1-4%)
HP:0001919	Acute kidney injury	Very rare (<1-4%)
HP:0001945	Fever	Very rare (<1-4%)
HP:0002063	Rigidity	Very rare (<1-4%)
HP:0002615	Hypotension	Very rare (<1-4%)
HP:0003201	Rhabdomyolysis	Very rare (<1-4%)
HP:0005521	Disseminated intravascular coagulation	Very rare (<1-4%)
HP:0031258	Delirium	Very rare (<1-4%)

Identifiers

Disease identifiers

Field	Value
Canonical name	serotonin syndrome
Mondo ID	MONDO:0018546
EFO	EFO:1001842
MeSH	D020230
Orphanet	43116
ICD-11	678764364
SNOMED CT	371089000
UMLS	C0699828
MedGen	152119
GARD	0018828
MedDRA	10040108
Is cancer (heuristic)	no

Also known as: serotonergic syndrome · serotonin storm · serotonin toxicity · serotonin toxidrome

Disease family

This is a subtype of nervous system disorder. Genetic, therapeutic, and trial evidence is largely curated at the broader-term level — see the parent page for the associated-gene cohort and molecular evidence.

Classification path: disease › human disease › disease by body system or component › nervous system disorder › serotonin syndrome

Related subtypes (71): congenital nervous system disorder, central nervous system disorder, autoimmune disorder of the nervous system, cranial nerve neuropathy, peripheral nervous system disorder, neuronitis, diplegia of upper limb, retinal disorder, developmental disability, restless legs syndrome, movement disorder, toxic encephalopathy, Barre-Lieou syndrome, Gerstmann syndrome, drug-induced akathisia, drug-induced dyskinesia, stiff-person syndrome, Worster-Drought syndrome, corneal-cerebellar syndrome, pachygyria-intellectual disability-epilepsy syndrome, porencephaly-cerebellar hypoplasia-internal malformations syndrome, symmetrical thalamic calcifications, neonatal brainstem dysfunction, primary orthostatic hypotension, rippling muscle disease with myasthenia gravis, periodic paralysis, qualitative or quantitative protein defects in neuromuscular diseases, specific learning disability, cerebellar hypoplasia-tapetoretinal degeneration syndrome, locked-in syndrome, dopa-responsive dystonia, idiopathic recurrent stupor, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids, spontaneous periodic hypothermia, Sydenham chorea, duplication of the pituitary gland, Balint syndrome, paraneoplastic neurologic syndrome, persistent idiopathic facial pain, hypothalamic adipsic hypernatraemia syndrome, exercise-induced malignant hyperthermia, perineural cyst, neuromuscular disease, neuromyelitis optica, AL amyloidosis, AA amyloidosis, neuroleptic malignant syndrome, infectious disorder of the nervous system, central nervous system malformation, synaptopathy, nervous system neoplasm, sensory ganglionopathy, radiculitis, wet beriberi, perceptual disorders, prepubertal anorexia nervosa, neurocutaneous syndrome, neurovascular disorder, Wallerian degeneration, nervous system injury, neurosarcoidosis, neuroendocrine disorder, tubulinopathy, atactic disorder, hereditary neurological disease, meningitis-retention syndrome, KIF1A related neurological disorder, neurological pain disorder, neurodevelopmental disorder, post 5-alpha-reductase inhibitors treatment syndrome, post-selective serotonin reuptake inhibitor sexual dysfunction

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

No tiered GWAS variants or ClinVar records for this disease.

Genes & proteins

No associated-gene cohort resolved for this disease. Atlas builds the molecular and therapeutic sections — associated genes, protein families, druggability, pathways, interactions, and drug associations — by aggregating over a disease’s associated genes (resolved via GWAS / GenCC / ClinVar / CIViC), and none resolved here. This is expected for antibody-mediated, autoimmune, or otherwise non-gene-defined conditions; the curated evidence for this disease is its clinical features, GWAS susceptibility, and clinical trials (above).

Function

No pathway enrichment — requires an associated-gene cohort.

Therapeutics

No druggable-target or therapeutic data for this disease’s cohort.

Clinical trials & evidence

Clinical trials

Clinical trials: 3.

Phase distribution (across all retrieved trials)

Phase	Trials
PHASE3	1
PHASE2	1
Not specified	1

Top trials by phase / activity

NCT	Phase	Status	Title
NCT04820751	PHASE3	UNKNOWN	Cyproheptadine in Severe COVID-19 : A Unblinded Randomized Trial
NCT04876573	PHASE2	UNKNOWN	Pilot Study for Cyproheptadine in Hospitalized Patient for COVID-19
NCT00955604	Not specified	COMPLETED	Azilect + Antidepressant Chart Review

Drugs tested across these trials (top 30)

Molecule	Max phase	Trials referencing
CYPROHEPTADINE	4	2
CHEMBL4588113	0	2