CLEMIZOLE

US Previously Marketed

First approved in 1960

Details

Stereochemistry	ACHIRAL
Molecular Formula	C19H20ClN3
Molecular Weight	325.835
Optical Activity	NONE
Defined Stereocenters	0 / 0
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

ClC1=CC=C(CN2C(CN3CCCC3)=NC4=C2C=CC=C4)C=C1

InChI

InChIKey=CJXAEXPPLWQRFR-UHFFFAOYSA-N

InChI=1S/C19H20ClN3/c20-16-9-7-15(8-10-16)13-23-18-6-2-1-5-17(18)21-19(23)14-22-11-3-4-12-22/h1-2,5-10H,3-4,11-14H2

HIDE SMILES / InChI

Molecular Formula	C19H20ClN3
Molecular Weight	325.835
Charge	0
Count

Stereochemistry	ACHIRAL
Additional Stereochemistry	No
Defined Stereocenters	0 / 0
E/Z Centers	0
Optical Activity	NONE

Description
Sources: https://www.ncbi.nlm.nih.gov/pubmed/23143674
Curator's Comment: Description was created based on several sources, including http://adisinsight.springer.com/drugs/800030702 https://www.ncbi.nlm.nih.gov/pubmed/25140002

Clemizole is a drug in clinical development for the treatment of hepatitis C virus (HCV) infection. Clemizole is a novel inhibitor of TRPC5 channels. Clemizole is an H1 antagonist. Clemizole, an antihistamine drug that was once widely used for treatment of allergic disease, was recently discovered to be a potent inhibitor (IC50, 24 nM) of the interaction between an HCV protein (NS4B) and HCV RNA. Although clemizole was widely used during the 1950s and 1960s, this was before contemporary regulatory requirements were established for new drug development, and there is very minimal information about its pharmacokinetics and metabolism.

CNS Activity

Originator

Approval Year

Targets

Primary Target	Pharmacology	Potency
Transient receptor potential cation channel subfamily M member 5 6 Target ID: CHEMBL1628468 Sources: https://www.ncbi.nlm.nih.gov/pubmed/25140002	Inhibitor 8504	1.0 µM [IC50]
Histamine H1 receptor 316 Target ID: CHEMBL231 Sources: https://www.ncbi.nlm.nih.gov/pubmed/1358393	Antagonist 2849
Hepatitis C virus 23 Target ID: CHEMBL379 Sources: https://www.ncbi.nlm.nih.gov/pubmed/20486856	Inhibitor 8504	8.0 µM [EC50]

Conditions

Condition	Modality	Targets	Highest Phase	Product
Allergic disease 6 Sources: https://www.ncbi.nlm.nih.gov/pubmed/14406465	Primary		Approved 8583	CLEMIZOLE Approved Use Allergic disease
Hepatitis C 42 Sources: http://adisinsight.springer.com/drugs/800030702	Primary		Phase I 438	Unknown Approved Use Unknown

T_1/2

Value	Dose	Co-administered	Analyte	Population
3.4 h EXPERIMENT https://www.ncbi.nlm.nih.gov/pubmed/23143674	100 mg single, oral dose: 100 mg route of administration: Oral experiment type: SINGLE co-administered:		CLEMIZOLE plasma	Homo sapiens population: UNKNOWN age: UNKNOWN sex: UNKNOWN food status: UNKNOWN

Overview

CYP3A4	CYP2C9	CYP2D6	hERG
substrate 1946	substrate 1193	substrate 1388	inhibitor 2217

OverviewOther

Other Inhibitor	Other Substrate	Other Inducer
	CYP2C19 1119 CYP1A2 1197

Drug as victim

Target	Modality	Activity	Metabolite	Clinical evidence
CYP1A2 1197	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes	A 5
CYP2C19 1119	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes	A 5
CYP2C9 1193	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes
CYP2C9 1193	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes	A 5
CYP2D6 1388	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes	A 5
CYP3A4 1946	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4.0	yes	A 5
CYP3A4 1946	substrate 4014 Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4,5	yes		likely (co-administration study) Comment: When coadministered with ritonavir (CYP3A4 inhibitor), decreased the amount of the human-predominant clemizole metabolites (M1 and M6) Sources: https://jpet.aspetjournals.org/content/344/2/388 Page: 4,5

Tox targets

Target	Modality	Activity	Metabolite	Clinical evidence
hERG 2263	inhibitor 2237 Sources: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241390/

Sourcing

Vendor/Aggregator	ID	URL
ChEBI	CHEBI:52140	https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:52140
ChemicalBook	CB3875322	https://www.chemicalbook.com/ChemicalProductProperty_EN_CB3875322
MolPort	MolPort-000-411-312	https://www.molport.com/shop/molecule-link/MolPort-000-411-312
ZINC	ZINC000000057260	http://zinc15.docking.org/substances/ZINC000000057260

PubMed

Title	Date	PubMed
Chemical genetics-based discovery of indole derivatives as HCV NS5B polymerase inhibitors.	2014-03-21	24561671
The Future of HCV Therapy: NS4B as an Antiviral Target.	2010-11	21157574
Green tea catechin, epigallocatechin gallate, suppresses signaling by the dsRNA innate immune receptor RIG-I.	2010-09-22	20877565
The hepatitis C virus (HCV) NS4B RNA binding inhibitor clemizole is highly synergistic with HCV protease inhibitors.	2010-07-01	20486856
Antiviral therapy for hepatitis C virus: beyond the standard of care.	2010-04	21994657
New strategies for the treatment of hepatitis C virus infection and implications of resistance to new direct-acting antiviral agents.	2010	21694902
Discovery of a hepatitis C target and its pharmacological inhibitors by microfluidic affinity analysis.	2008-09	18758449
[Current syphilis therapies and serological control. Commentary on the article by M. Hartmann in Hautarzt, Volume 2 (2004)].	2004-11	15448930
Application of capillary electrophoresis to the determination of various benzylpenicillin salts.	2004-04-02	15065804
[Antimycobacterial antihistaminics].	1989-08	2513793

Patents

Sample Use Guides

In Vivo Use Guide

100 mg Clemizole Hydrochloride Administered Orally Twice a Day for 28 Days

Route of Administration: Oral

In Vitro Use Guide

The contractile response to histamine was antagonized by the histamine H1-receptor antagonist, clemizole (0.1 uM), in human isolated myometrial strips. Clemizole (0.1 nM to 10 nM) competitively antagonized the contractile effect of 2-pyridylethylamine.

Substance Class	Chemical Created by `admin` on `Mon Mar 31 17:48:45 GMT 2025` Edited by `admin` on `Mon Mar 31 17:48:45 GMT 2025`
Record UNII	T97CB3796L
Record Status	`Validated (UNII)`
Record Version

Download

Name

Type

Language

CLEMIZOLE

Official Name

English

AL-20 FREE BASE

Preferred Name

English

Clemizole [WHO-DD]

Common Name

English

CLEMIZOLE [MI]

Common Name

English

CLEMIZOLE [USAN]

Common Name

English

1-P-CHLOROBENZYL-2-(1-PYRROLIDINYLMETHYL)BENZIMIDAZOLE

Systematic Name

English

NSC-46261

Code

English

clemizole [INN]

Common Name

English

Classification Tree Code System Code

FDA ORPHAN DRUG

566116