Famotidine

Summary

Famotidine (CHEMBL902) is an approved small-molecule anti-ulcer drug (ATC A02BA03) targeting HRH2 and TAS2R31; indicated across 36 conditions including peptic ulcer disease and gastroesophageal reflux disease.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: A02BA03 (+1 more)
• Targets: 2 (HRH2, TAS2R31)
• Indications: 36 conditions
• Clinical trials: 104
• Chemistry: 337.5 Da · C8H15N7O2S3

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL902
Name	Famotidine
Type	Small molecule
Max phase	4
FDA approved	no
PubChem CID	5353622
ChEBI	CHEBI:4975
ATC	A02BA03, A02BA53
Molecular formula	C8H15N7O2S3
Molecular weight	337.5
InChIKey	XUFQPHANEAPEMJ-UHFFFAOYSA-N

SMILES: C1=C(N=C(S1)N=C(N)N)CSCC/C(=N\S(=O)(=O)N)/N

IUPAC name: 3-[[2-(diaminomethylideneamino)-1,3-thiazol-4-yl]methylsulfanyl]-N’-sulfamoylpropanimidamide

Pharmacological roles (ChEBI): anti-ulcer drug, H2-receptor antagonist, P450 inhibitor.

Also known as: Amfamox, Fadul, Famodil, Famosan, Famotidina, Famotidine, Famotidine component of duexis, Famotidine component of pepcid complete, Famotidine preservative free, Famoxal, Fluxid, Ganor

Patent coverage: 20,582 distinct patent families (66,828 SureChEMBL compound mentions), from 7 matched compound structure(s). Mentions count patents naming the compound (not distinct inventions), so promiscuous / reference molecules inflate the mention figure — families are the dedup metric.

Targets

Targets

Primary targets (GtoPdb curated mechanism): the Cancer dependency column is the DepMap CRISPR fitness signal (% of screened cell lines dependent on the target).

Gene	Target	Action	pAffinity	Cancer dependency	UniProt
HRH2	H2 receptor	Antagonist			P25021
TAS2R31	TAS2R31	Agonist		0%	P59538

Broader ChEMBL bioactivity targets: 26 (assay-derived). Sample: Prelamin-A/C, RecQ-like DNA helicase BLM, Inositol monophosphatase 1, 4’-phosphopantetheinyl transferase ffp, Peripheral myelin protein 22, Solute carrier family 22 member 2, Multidrug and toxin extrusion protein 1, Multidrug and toxin extrusion protein 2, Histamine H2 receptor, Amine oxidase [flavin-containing] A.

Bioactivity

ChEMBL activities: 26 potent at pChembl ≥ 5 of 37 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
BLM	8.8	Potency	1.6	nM	CHEMBL_ACT_4742014
BLM	8.8	Potency	1.6	nM	CHEMBL_ACT_4917744
CA7	8.52	Ki	3	nM	CHEMBL_ACT_18778841
HRH2	8.2	AC50	6.3	nM	CHEMBL_ACT_25114343
P47747	7.74	Kd	18.2	nM	CHEMBL_ACT_78912
LMNA	7.55	Potency	28.2	nM	CHEMBL_ACT_3662626
HRH2	7.39	Ki	41	nM	CHEMBL_ACT_7658964
HRH2	7.38	IC50	42	nM	CHEMBL_ACT_7658963
CA12	7.34	Ki	45.3	nM	CHEMBL_ACT_18778837
CA2	7.24	Ki	57.9	nM	CHEMBL_ACT_18778853
CA6	7.01	Ki	98.2	nM	CHEMBL_ACT_18778843
P47747	7	Kd	100	nM	CHEMBL_ACT_1067300
CA9	6.9	Ki	126.3	nM	CHEMBL_ACT_18778839
CA13	6.77	Ki	171.5	nM	CHEMBL_ACT_18778835
LMNA	6.55	Potency	281.8	nM	CHEMBL_ACT_3651231
P47747	6.52	IC50	300	nM	CHEMBL_ACT_249352
CA14	6.17	Ki	677.2	nM	CHEMBL_ACT_18778833
SLC47A1	6.12	IC50	760	nM	CHEMBL_ACT_12637812
CA1	6.04	Ki	922.4	nM	CHEMBL_ACT_18778855
CA4	6.03	Ki	938.8	nM	CHEMBL_ACT_18778849
CA5A	5.84	Ki	1430	nM	CHEMBL_ACT_18778847
P97697	5.3	Potency	5012	nM	CHEMBL_ACT_4411614
CA5B	5.27	Ki	5328	nM	CHEMBL_ACT_18778845
LMNA	5.25	Potency	5623	nM	CHEMBL_ACT_3624982
MAOA	5.09	AC50	8100	nM	CHEMBL_ACT_25159249
P25779	5	Potency	10000	nM	CHEMBL_ACT_3986547

Target pathways

Aggregated over 2 target gene(s): HRH2, TAS2R31.

Top Reactome pathways

11 total, by targets touching each:

Pathway	Targets	Genes
Signal Transduction	1	TAS2R31
Signaling by GPCR	1	TAS2R31
GPCR downstream signalling	1	TAS2R31
Histamine receptors	1	HRH2
G alpha (s) signalling events	1	HRH2
G alpha (i) signalling events	1	TAS2R31
Class C/3 (Metabotropic glutamate/pheromone receptors)	1	TAS2R31
GPCR ligand binding	1	TAS2R31
Sensory Perception	1	TAS2R31
Sensory perception of taste	1	TAS2R31
Sensory perception of sweet, bitter, and umami (glutamate) taste	1	TAS2R31

Dominant GO biological processes

GO term	Targets
signal transduction	2
G protein-coupled receptor signaling pathway	2
gastric acid secretion	1
immune response	1
G protein-coupled receptor signaling pathway, coupled to cyclic nucleotide second messenger	1
adenylate cyclase-activating G protein-coupled receptor signaling pathway	1
chemical synaptic transmission	1
positive regulation of vasoconstriction	1
detection of chemical stimulus involved in sensory perception of bitter taste	1
sensory perception of taste	1

Indications & clinical

Indications

36 indications (10 at ChEMBL trial phase 4). Phase below is the highest clinical-trial phase recorded for this drug against each disease — not the molecule’s overall approval status (that is in the Summary).

Indication	Trial phase	MONDO	EFO
peptic ulcer disease	4	MONDO:0004247	HP:0004398
gastroesophageal reflux disease	4	MONDO:0007186	EFO:0003948
rheumatoid arthritis	4	MONDO:0008383	EFO:0000685
duodenal ulcer	4	MONDO:0005412	EFO:0004607
gastric ulcer	4	MONDO:0001126	EFO:0009454
esophagitis	4	MONDO:0001409	HP:0100633
ulcer disease	4	MONDO:0043839	MONDO:0043839
osteoarthritis	4	MONDO:0005178	MONDO:0005178
severe acute respiratory syndrome	3	MONDO:0005091	MONDO:0100096
movement disorder	2	MONDO:0005395	EFO:0004280
eosinophilic esophagitis	2	MONDO:0005361	EFO:0004232
gastric neoplasm	2	MONDO:0021085	MONDO:0001056
breast carcinoma in situ	2	MONDO:0004658	MONDO:0004658
sickle cell disease	2	MONDO:0011382	MONDO:0011382
breast carcinoma	2	MONDO:0004989	EFO:0000305
gastric adenocarcinoma	2	MONDO:0005036	EFO:0000503
breast neoplasm	2	MONDO:0021100	MONDO:0007254
psoriasis	1	MONDO:0005083	EFO:0000676
HIV infectious disease	1	MONDO:0005109	EFO:0000180
thyroid gland papillary carcinoma	1	MONDO:0005075	EFO:0000641
melanoma	1	MONDO:0005105	EFO:0000756
non-small cell lung carcinoma	1	MONDO:0005233	EFO:0003060
neoplasm	1	MONDO:0005070	EFO:0000616
glycogen storage disease III	1	MONDO:0009291	MONDO:0009291
mesothelioma	1	MONDO:0005065	EFO:0000588
hairy cell leukemia	1	MONDO:0018935	EFO:1000956
colorectal neoplasm	1	MONDO:0005335	MONDO:0005575
systemic lupus erythematosus	1	MONDO:0007915	MONDO:0007915

8 further indication records had no mapped disease name (EFO/MeSH-only) or were duplicates, and are omitted.

Clinical trials

Total trials: 104.

Phase distribution

Phase	Trials
PHASE1	45
PHASE2	16
PHASE4	15
Not specified	10
PHASE3	9
PHASE2/PHASE3	5
PHASE1/PHASE2	4

Top trials by phase / activity

NCT	Phase	Status	Title
NCT05455359	PHASE4	RECRUITING	Gastrointestinal Dysmotility on Aspiration Risk
NCT06241183	PHASE4	RECRUITING	Famotidine and Antacids for Treatment of Dyspepsia
NCT06743243	PHASE4	ENROLLING_BY_INVITATION	Effect of Tegoprazan for Elective Surgery Patients Under General Anesthesia
NCT07101445	PHASE4	RECRUITING	Evaluating Premedication Regimens (Methylprednisolone vs Dexamethasone-based) for the Prevention of Systemic and Injection Site Reactions to Motixafortide in Patients With Multiple Myeloma Undergoing Stem Cell Mobilization, PARADE Trial
NCT00557349	PHASE4	COMPLETED	Ulcer Prevention Study in Post Gastric Bypass Patients
NCT00565175	PHASE4	COMPLETED	Histamine H2 Antagonism as Adjuvant Therapy in Treatment Resistant Schizophrenia
NCT00633035	PHASE4	COMPLETED	Comparison of Esomeprazole and Famotidine for Stress Ulcer Prophylaxis in Neurosurgical Intensive Care Unit
NCT00978159	PHASE4	UNKNOWN	Esomeprazole or Famotidine in the Management of Aspirin Related Non-Ulcer Dyspepsia
NCT01180179	PHASE4	COMPLETED	PPI vs H2RA in Patients With Helicobacter Pylori-Negative Idiopathic Bleeding Ulcers
NCT01232127	PHASE4	COMPLETED	Effects of Famotidine on the Pharmacokinetics of Atazanavir When Coadministered to Participants With HIV Infection
NCT01928888	PHASE4	COMPLETED	Placebo Controlled Phase IV Study to Compare the Efficacy and Safety of a Single Dose of Oral Talcid, a Single Dose of Oral Famotidine and a Single Dose of Placebo in Patients With Acute Heartburn Episodes
NCT03667703	PHASE4	COMPLETED	Stress Ulcer Prophylaxis Versus Placebo in Critically Ill Infants With Congenital Heart Disease
NCT04565392	PHASE4	WITHDRAWN	Remotely-conducted Trial of Famotidine vs Placebo for Patients at Home With Coronavirus (COVID) of 2019 (COVID-19)
NCT04766996	PHASE4	TERMINATED	PROUD Study - Preventing Opioid Use Disorders
NCT04836806	PHASE4	WITHDRAWN	Cetirizine and Famotidine for COVID-19
NCT06801626	PHASE3	RECRUITING	Novel Strategies for Reducing Burn Scar Itch
NCT00141960	PHASE2/PHASE3	COMPLETED	Famotidine in Subjects With Non-erosive Gastroesophageal Reflux Disease
NCT00229424	PHASE3	COMPLETED	Verification Study on Lafutidine in Mild Reflux Oesophagitis - Double Blind Controlled Study With Famotidine -
NCT00450216	PHASE3	COMPLETED	Efficacy and Safety Study of HZT-501 in Subjects Requiring Nonsteroidal Anti-Inflammatory Drug (NSAID) Treatment
NCT01408186	PHASE3	COMPLETED	ASP (PPI_H2RA) Study-H2RA Versus PPI for the Prevention of Recurrent UGIB in High-risk Users of Low-dose ASA
NCT01499368	PHASE3	COMPLETED	A Multi-center, Randomized, Double-blind Phase III Clinical Trial to Assess and Compare to the Efficacy and Safety of Lafutidine, Famotidine and Omeprazole-referenced in Korean Erosive Esophagitis Patients
NCT01946295	PHASE2/PHASE3	UNKNOWN	Famotidine in Schizophrenia
NCT04370262	PHASE3	COMPLETED	Multi-site Adaptive Trials for COVID-19
NCT04504240	PHASE3	COMPLETED	Role of Famotidine in the Clinical Improvement of COVID-19 Patients.
NCT04862585	PHASE2/PHASE3	COMPLETED	Safely Stopping Pre-medications in Patients With Breast Cancer Who Are Receiving Paclitaxel
NCT05043350	PHASE2/PHASE3	COMPLETED	Combined Antihistaminics Therapy in COVID 19 Patients
NCT05084521	PHASE2/PHASE3	COMPLETED	Interest of Famotidine in Children With Sickle Cell Disease
NCT05946551	PHASE3	TERMINATED	Treatment of Long CoronaVirus Disease (COVID) (TLC) Feasibility Trial
NCT05965492	PHASE3	WITHDRAWN	Multimodal Pain Package vs. Regular Formulation for Pain Management in Ambulatory Spinal Surgery
NCT04488081	PHASE2	ACTIVE_NOT_RECRUITING	I-SPY COVID-19 TRIAL: An Adaptive Platform Trial for Critically Ill Patients
NCT04724720	PHASE2	ACTIVE_NOT_RECRUITING	Famotidine vs Placebo for the Treatment of Non-Hospitalized Adults With COVID-19
NCT05977998	PHASE2	RECRUITING	A Phase II Study of Perioperative Paclitaxel in Patients With Gastric Adenocarcinoma and Carcinomatosis or Positive Cytology
NCT06207305	PHASE1/PHASE2	RECRUITING	A Phase I/II Study of Intraperitoneal Paclitaxel in Patients With Metastatic Appendiceal Adenocarcinoma
NCT06481306	PHASE1/PHASE2	RECRUITING	A Study to Evaluate BMS-986470 in Healthy Volunteers and Participants With Sickle Cell Disease
NCT06819670	PHASE2	RECRUITING	A Study to Prevent Infantile Spasms Relapse
NCT01937078	PHASE2	COMPLETED	Famotidine for Levodopa-induced Dyskinesia in PD
NCT02142712	PHASE2	COMPLETED	Histamine Glutamate Antagonism in Stroke
NCT03107182	PHASE2	COMPLETED	Chemotherapy and Locoregional Therapy Trial (Surgery or Radiation) for Patients With Head and Neck Cancer
NCT03554291	PHASE2	COMPLETED	Repurposing a Histamine Antagonist to Benefit Patients With Pulmonary Hypertension
NCT04248712	PHASE2	TERMINATED	Antihistamines in Eosinophilic Esophagitis

Clinical evidence (CIViC)

No CIViC predictive evidence (expected for non-precision-medicine drugs).

Pharmacology

Pharmacogenomics

No PharmGKB pharmacogenomic data curated for this drug.

Related molecules

Related molecules

Molecules sharing ≥1 of this drug’s curated primary targets, merged from two biobtree sources and ranked by shared-target count, then clinical phase: ChEMBL clinical-stage candidates (development phase ≥2) and PubChem drug-class bioactivity (approved / known drugs acting on the target). Deduplicated by drug name; the drug’s own salt forms are excluded. Note: for a drug with few primary targets a shared-target match can reflect off-target / promiscuous binding rather than the same therapeutic mechanism — the phase ordering surfaces bona-fide therapeutics first.

170 molecules share ≥1 primary target. Top 60 by shared-target count:

Molecule	Source	Status	Shared targets
Cinacalcet	ChEMBL + PubChem	Phase 4 (approved)	HRH2
CLOZAPINE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
CRIZOTINIB	ChEMBL + PubChem	Phase 4 (approved)	HRH2
DESLORATADINE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
DIHYDROERGOTAMINE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
LINAGLIPTIN	ChEMBL + PubChem	Phase 4 (approved)	HRH2
OLANZAPINE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
PIMOZIDE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
PRAMIPEXOLE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
PROPOXYPHENE	ChEMBL + PubChem	Phase 4 (approved)	HRH2
AMIODARONE	ChEMBL	Phase 4 (approved)	HRH2
AMITRIPTYLINE	ChEMBL	Phase 4 (approved)	HRH2
AMLODIPINE	ChEMBL	Phase 4 (approved)	HRH2
AMOXAPINE	ChEMBL	Phase 4 (approved)	HRH2
ARIPIPRAZOLE	ChEMBL	Phase 4 (approved)	HRH2
ASENAPINE	ChEMBL	Phase 4 (approved)	HRH2
ASTEMIZOLE	ChEMBL	Phase 4 (approved)	HRH2
BENZTROPINE	ChEMBL	Phase 4 (approved)	HRH2
BETAZOLE	ChEMBL	Phase 4 (approved)	HRH2
BOSUTINIB	ChEMBL	Phase 4 (approved)	HRH2
BROMOCRIPTINE	ChEMBL	Phase 4 (approved)	HRH2
CABERGOLINE	ChEMBL	Phase 4 (approved)	HRH2
CARVEDILOL	ChEMBL	Phase 4 (approved)	HRH2
CETIRIZINE	ChEMBL	Phase 4 (approved)	HRH2
CHLORPHENIRAMINE	ChEMBL	Phase 4 (approved)	HRH2
CHLORPROMAZINE	ChEMBL	Phase 4 (approved)	HRH2
CIMETIDINE	ChEMBL	Phase 4 (approved)	HRH2
CITALOPRAM	ChEMBL	Phase 4 (approved)	HRH2
CLEMASTINE	ChEMBL	Phase 4 (approved)	HRH2
CLOMIPRAMINE	ChEMBL	Phase 4 (approved)	HRH2
CLONIDINE	ChEMBL	Phase 4 (approved)	HRH2
CLOTRIMAZOLE	ChEMBL	Phase 4 (approved)	HRH2
CYPROHEPTADINE	ChEMBL	Phase 4 (approved)	HRH2
DARIFENACIN	ChEMBL	Phase 4 (approved)	HRH2
DEXCHLORPHENIRAMINE	ChEMBL	Phase 4 (approved)	HRH2
DICYCLOMINE	ChEMBL	Phase 4 (approved)	HRH2
DILTIAZEM	ChEMBL	Phase 4 (approved)	HRH2
DIPHENHYDRAMINE	ChEMBL	Phase 4 (approved)	HRH2
DOXAZOSIN	ChEMBL	Phase 4 (approved)	HRH2
DOXEPIN	ChEMBL	Phase 4 (approved)	HRH2
DYCLONINE	ChEMBL	Phase 4 (approved)	HRH2
EBASTINE	ChEMBL	Phase 4 (approved)	HRH2
ECONAZOLE	ChEMBL	Phase 4 (approved)	HRH2
ENCAINIDE	ChEMBL	Phase 4 (approved)	HRH2
FLUOXETINE	ChEMBL	Phase 4 (approved)	HRH2
FLUPHENAZINE	ChEMBL	Phase 4 (approved)	HRH2
GENTIAN VIOLET	ChEMBL	Phase 4 (approved)	HRH2
HALOPERIDOL	ChEMBL	Phase 4 (approved)	HRH2
HISTAMINE	ChEMBL	Phase 4 (approved)	HRH2
HYDROXYZINE	ChEMBL	Phase 4 (approved)	HRH2
IMATINIB	ChEMBL	Phase 4 (approved)	HRH2
IMIPRAMINE	ChEMBL	Phase 4 (approved)	HRH2
IMIQUIMOD	ChEMBL	Phase 4 (approved)	HRH2
INDOCYANINE GREEN ACID FORM	ChEMBL	Phase 4 (approved)	HRH2
IPRINDOLE	ChEMBL	Phase 4 (approved)	HRH2
ISOPROTERENOL	ChEMBL	Phase 4 (approved)	TAS2R31
KETOCONAZOLE	ChEMBL	Phase 4 (approved)	HRH2
KETOTIFEN	ChEMBL	Phase 4 (approved)	HRH2
LANSOPRAZOLE	ChEMBL	Phase 4 (approved)	HRH2
LOPERAMIDE	ChEMBL	Phase 4 (approved)	HRH2