chlorzoxazone

Trade name: parafon forte dsc

Small moleculeapproved

Approved

Aug 15, 1958

Chlorzoxazone is a centrally acting central muscle relaxant with sedative properties. It is claimed to inhibit muscle spasm by exerting an effect primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex arcs involved in producing and maintaining skeletal muscle spasm of varied etiology. The clinical result is a reduction of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles. Chlorzoxazone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Chlorzoxazone does not directly relax tense skeletal muscles in man. — NCATS

Clinical trial activity

5 trials · 6 clinical orgs · 37 marketing orgs

Phase 1

Phase 2

Phase 3

Phase 4

Earliest trial started Dec 1, 2005 (NCT00330434)

Timeline

1950s

Aug 15, 1958
Janssen Pharmaceutica NV — Earliest FDA Approval
Aug 15, 1958
Johnson and Johnson — NDA Secondary Org
Aug 15, 1958
Janssen Pharmaceutica NV — NDA Organization

1980s

Oct 6, 1981
Watson Pharmaceuticals — Marketing Organization
Sep 20, 1983
Par Pharmaceuticals — Marketing Organization
Sep 20, 1983
Strides Pharma Science — Marketing Organization
May 8, 1987
Actavis — Marketing Organization
May 4, 1988
Aurobindo Pharma — Marketing Organization
May 4, 1988
Barr Laboratories — Marketing Organization
May 4, 1988
Rising Pharmaceuticals — Marketing Organization
Dec 23, 1988
Ferndale Laboratories, Inc. — Marketing Organization

1990s

Sep 27, 1990
Sun Pharmaceuticals — Marketing Organization
Dec 29, 1993
Ohm Laboratories, Inc. — Marketing Organization

2010s

Jun 1, 2010
Mikart — Marketing Organization
Jun 1, 2010
ANDA Repository — Marketing Organization
Sep 12, 2019
Novitium Pharma — Marketing Organization

2020s

May 26, 2020
Glenmark Pharmaceuticals — Marketing Organization
Jun 17, 2020
Teva — Marketing Organization
Jul 21, 2020
Mayne Pharma — Marketing Organization
Jul 21, 2020
Dr. Reddy's Laboratories — Marketing Organization
Sep 14, 2020
Chartwell Pharmaceuticals — Marketing Organization
Sep 14, 2020
Aptapharma Inc — Marketing Organization
Sep 15, 2020
I3 Pharms — Marketing Organization
Nov 2, 2020
Endo Pharmaceuticals — Marketing Organization
Nov 2, 2020
Bristol-Myers Squibb — Marketing Organization
Nov 2, 2020
PH HEALTH — Marketing Organization
Jul 29, 2021
Senores Pharms — Marketing Organization
Jul 29, 2021
RISE PHARMA — Marketing Organization
Jan 1, 2022
Earliest Phase 1 Sponsor(trial)
Oct 20, 2022
Corepharma — Marketing Organization
Oct 20, 2022
Amneal Pharmaceuticals — Marketing Organization
Jan 24, 2023
Belcher Pharmaceuticals — Marketing Organization
Jan 24, 2023
AJENAT PHARMS — Marketing Organization
Jan 27, 2023
Appco Pharma — Marketing Organization
Jan 27, 2023
Upsher-Smith Laboratories — Marketing Organization
Jan 27, 2023
Somerset Pharmaceuticals — Marketing Organization
Apr 27, 2023
ACME Laboratories — Marketing Organization
Aug 9, 2023
Graviti Pharmaceuticals — Marketing Organization

Indications

Approved for

Spasm (approved 1988)

Studied for

Mechanism of action

Intermediate conductance calcium-activated potassium channel protein 4OPENER
KCNN4 opener
- Intermediate conductance calcium-activated potassium channel protein 4 (KCNN4) ↗

Approval history

approvedAug 15, 1958

Chemistry & pharmacology

Loading structure…

SMILES

ClC1=CC2=C(OC(=O)N2)C=C1

Mol. weight: 169.565 g/mol
Lipinski Ro5: Pass
Rule of 3: Yes
Chirality: Achiral Molecule
Inorganic: No
Polymer: No
Delivery: Oral
Availability: Prescription Only

Oral

Yes

Parenteral

Topical

Sources

Also known as

2-hydroxy-5-chlorobenzoxazole
2-hydroxy-5-chlorobenzoxazole
5-chloro-2(3h)-benzoxazolone
5-chloro-2(3h)-benzoxazolone
5-chloro-2-benzoxazolinone
5-chloro-2-benzoxazolinone
5-chloro-2-benzoxazolol
5-chloro-2-benzoxazolol
5-chloro-2-benzoxazolone
5-chloro-2-benzoxazolone
5-chloro-2-hydroxybenzoxazole
5-chloro-2-hydroxybenzoxazole
5-chloro-3h-benzooxazol-2-one
5-chloro-3h-benzooxazol-2-one
5-chlorobenzoxazolidone
5-chlorobenzoxazolidone
5-chlorobenzoxazolidone
5-chlorobenzoxazolin-2-one
5-chlorobenzoxazolin-2-one
chloroxazone
chlorzoxane
chlorzoxane
chlorzoxazon
chlorzoxazon
chlorzoxazon
chlorzoxazona
chlorzoxazona
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazone
chlorzoxazonum
chlorzoxazonum
clorzoxazona
clorzoxazona
clorzoxazone
clorzoxazone
paraflex
paraflex
paraflex
parafon
parafon
parafon forte
parafon forte
parafon-forte
parafon-forte
parafon forte dsc
parafon forte dsc
strifon
strifon
strifon forte dsc
strifon forte dsc

Clinical trials

NCT ID	Phase	Start date	Sponsor(s)
NCT05257447	Phase 1	Apr 27, 2022	The University of Texas, Dallas, Tufts University
NCT02405104	Phase 4	Sep 1, 2015	Government of Denmark
NCT01933542	Phase 4	Aug 1, 2013	University of Copenhagen
NCT01342341	Phase 4	Apr 1, 2011	University of California, San Francisco
NCT00330434	N/A	Dec 1, 2005	National Institute on Alcohol Abuse and Alcoholism (NIAAA), Tufts University

Showing 5 of 5 trials

Page 1 / 1

Organizations

Research & Development (6)

Organization	Org type	Trials	As lead sponsor	Phases	Earliest year
Tufts University	Academic/Hospital	2	0	2	2005
Government of Denmark	Government	1	1	1	2015
National Institute on Alcohol Abuse and Alcoholism (NIAAA)	Government	1	1	1	2005
The University of Texas, Dallas	Academic/Hospital	1	1	1	2022
University of California, San Francisco	Academic/Hospital	1	1	1	2011
University of Copenhagen	Academic/Hospital	1	1	1	2013

6 organizations

Page 1 / 1

Marketing (39)

Organization	Org type	Relationship	Date
ACME Laboratories	For profit	MKTG	Apr 27, 2023
AJENAT PHARMS	For profit	MKTG	Jan 24, 2023
ANDA Repository	For profit	MKTG	Jun 1, 2010
Actavis	For profit	MKTG	May 8, 1987
Amneal Pharmaceuticals	For profit	MKTG	Oct 20, 2022
Appco Pharma	For profit	MKTG	Jan 27, 2023
Aptapharma Inc	For profit	MKTG	Sep 14, 2020
Aurobindo Pharma	For profit	MKTG	May 4, 1988
Aurobindo Pharma	For profit	SYN	May 4, 1988
Barr Laboratories	For profit	MKTG	May 4, 1988
Belcher Pharmaceuticals	For profit	MKTG	Jan 24, 2023
Bristol-Myers Squibb	For profit	MKTG	Nov 2, 2020
Chartwell Pharmaceuticals	For profit	MKTG	Sep 14, 2020
Corepharma	For profit	MKTG	Oct 20, 2022
Dow Chemical	For profit	MKTG	—
Dr. Reddy's Laboratories	For profit	MKTG	Jul 21, 2020
Endo Pharmaceuticals	For profit	MKTG	Nov 2, 2020
Ferndale Laboratories, Inc.	For profit	MKTG	Dec 23, 1988
Glenmark Pharmaceuticals	For profit	MKTG	May 26, 2020
Graviti Pharmaceuticals	For profit	MKTG	Aug 9, 2023
I3 Pharms	For profit	MKTG	Sep 15, 2020
Janssen Pharmaceutica NV	For profit	NDA	Aug 15, 1958
Johnson and Johnson	For profit	NDA2	Aug 15, 1958
Mayne Pharma	For profit	MKTG	Jul 21, 2020
Mikart	For profit	MKTG	Jun 1, 2010
Novitium Pharma	For profit	MKTG	Sep 12, 2019
Ohm Laboratories, Inc.	For profit	MKTG	Dec 29, 1993
PH HEALTH	For profit	MKTG	Nov 2, 2020
Par Pharmaceuticals	For profit	MKTG	Sep 20, 1983
Par Pharmaceuticals	For profit	SYN	Nov 2, 2020
RISE PHARMA	For profit	MKTG	Jul 29, 2021
Rising Pharmaceuticals	For profit	MKTG	May 4, 1988
Senores Pharms	For profit	MKTG	Jul 29, 2021
Somerset Pharmaceuticals	For profit	MKTG	Jan 27, 2023
Strides Pharma Science	For profit	MKTG	Sep 20, 1983
Sun Pharmaceuticals	For profit	MKTG	Sep 27, 1990
Teva	For profit	MKTG	Jun 17, 2020
Upsher-Smith Laboratories	For profit	MKTG	Jan 27, 2023
Watson Pharmaceuticals	For profit	MKTG	Oct 6, 1981