U.S. patent application number 10/114148 was filed with the patent office on 2002-12-05 for methods for treating hyperactive gastric motility.
This patent application is currently assigned to Wyeth. Invention is credited to Argentieri, Thomas M..
Application Number | 20020183395 10/114148 |
Document ID | / |
Family ID | 23077446 |
Filed Date | 2002-12-05 |
United States Patent
Application |
20020183395 |
Kind Code |
A1 |
Argentieri, Thomas M. |
December 5, 2002 |
Methods for treating hyperactive gastric motility
Abstract
This invention provides methods and pharmaceutical compositions
for treating, inhibiting or preventing hyperactive gastric motility
in a mammal utilizing agonists of KCNQ potassium channels,
including KCNQ2, KCNQ3, KCNQ4 and KCNQ5 potassium channels, alone
or in combination. The hyperactive gastric motility may be
associated with maladies including, colitis, irritable bowel
syndrome and Crohn's disease. Compounds useful in these methods
include the 1,2,4-triamino-benzene derivatives described in U.S.
Pat. No. 5,384,330 (Dieter et al.) and the substituted 3-phenyl
oxindole compounds described in U.S. Pat. No. 5,565,483 (Hewawasam
et al.). Among the preferred compounds of this invention is
N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid ethyl
ester, also referred to as retigabine.
Inventors: |
Argentieri, Thomas M.;
(Yardley, PA) |
Correspondence
Address: |
George M. Tarnowski
5 Giralda Farms
Madison
NJ
07940
US
|
Assignee: |
Wyeth
Madison
NJ
|
Family ID: |
23077446 |
Appl. No.: |
10/114148 |
Filed: |
April 2, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60281471 |
Apr 4, 2001 |
|
|
|
Current U.S.
Class: |
514/616 ;
514/617 |
Current CPC
Class: |
A61K 31/325 20130101;
A61K 31/4015 20130101; A61P 1/00 20180101; A61K 31/165 20130101;
A61K 31/167 20130101; A61K 31/00 20130101 |
Class at
Publication: |
514/616 ;
514/617 |
International
Class: |
A61K 031/165 |
Claims
What is claimed:
1. A method of treatment or inhibition of hyperactive gastric
motility in a mammal, the method comprising administering to a
mammal in need thereof a pharmacologically effective amount of a
KCNQ potassium channel agonist.
2. The method of claim 1 wherein the KCNQ potassium channel is a
KCNQ4 potassium channel.
3. The method of claim 1 wherein the KCNQ potassium channel is a
KCNQ2/3 potassium channel.
4. The method of claim 1 wherein the KCNQ potassium channel is a
KCNQ3/5 potassium channel.
5. The method of claim 1 wherein the hyperactive gastric motility
in a mammal is associated with inflammatory bowel disease.
6. The method of claim 1 wherein the hyperactive gastric motility
in a mammal is associated with Crohn's disease.
7. A method of treatment or inhibition of hyperactive gastric
motility in a mammal, the method comprising administering to a
mammal in need thereof a pharmacologically effective amount of a
compound of the formula: 12wherein: R.sub.1 is selected from
hydrogen, C.sub.1--C.sub.6-alkyl, C.sub.2--C.sub.6-alkanoyl or the
radical Ar; R.sub.2 is selected from hydrogen or
C.sub.1--C.sub.6-alkyl; R.sub.3 is selected from
C.sub.1--C.sub.6-alkoxy, NH.sub.2, C.sub.1--C.sub.6-alkylamino,
C.sub.1--C.sub.6-dialkylamino, amino substituted by the radical Ar,
C.sub.1--C.sub.6-alkyl, C.sub.2--C.sub.6-alkenyl,
C.sub.2--C.sub.6-alkyny- l, the radical Ar or the radical ArO--;
R.sub.4 is selected from hydrogen, C.sub.1--C.sub.6-alkyl or the
radical Ar; R.sub.5 is selected from hydrogen or
C.sub.1--C.sub.6-alkyl or the radical Ar; Alk: a straight or
branched alkylene group with 1-0 carbon atoms, which can also be
substituted by the radical Ar; Ar is a phenyl radical substituted
by the radicals R.sub.6, R.sub.7 and/or R.sub.8 where these
radicals R.sub.6, R.sub.7 and R.sub.8 are the same or different and
represent C.sub.1--C.sub.6-alkyl, C.sub.3--C.sub.7-cycloalkyl,
hydroxy, C.sub.1--C.sub.6-alkoxy, C.sub.2--C.sub.6-alkanoyloxy,
halogen, hydroxy, C.sub.1--C.sub.6-halogenoalkyl, --CN, --NH.sub.2,
--NH--C.sub.1--C.sub.6-- alkyl, --N(C.sub.1--C.sub.6-alkyl).sub.2,
--CO.sub.2H, --CO--C.sub.1--C.sub.6-alkyl,
--CO--O--C.sub.1--C.sub.6-alkyl, --COAr, --CO--OAr, --CONH.sub.2,
--CONH--C.sub.1--C.sub.6-alkyl,
--CON(C.sub.1--C.sub.6-alkyl).sub.2, --CONHAr,
--NH--CO--C.sub.1--C.sub.6- -alkyl, --NHCO--Ar,
--NHCO--C.sub.1--C.sub.6-alkoxy, --N--H--CO--Ar, --N HCO--NH.sub.2,
--NHCO--N(--C.sub.1--C.sub.6-alkyl).sub.2, --NHCO--NHAr,
--NH--SO.sub.2--C--1--C.sub.6-alkyl, --NH--SO.sub.2Ar,
--NH--SO.sub.2-nitrophenyl, --SO.sub.2--OH,
--SO.sub.2--C.sub.1--C.sub.6-- alkyl, --SO.sub.2--Ar,
--SO.sub.2--C.sub.1--C.sub.6-alkoxy, --SO.sub.2--OAr,
--SO.sub.2--NH.sub.2, --SO.sub.2--NH--C.sub.1--C.sub.6-a- lkyl,
--SO.sub.2--N(C.sub.1--C.sub.6-alkyl).sub.2, --SO.sub.2--NHAr,
--SO.sub.2--C.sub.1--C.sub.6-alkoxy; n is 0 or 1; or a
pharmaceutically acceptable salt thereof.
8. A method of claim 7 in which the compound is selected from the
group of:
2-Amino-4-(4-fluorobenzylamino)-1-ethoxycarbonylaminobenzene;
2-Amino-4-(4-trifluoromethylbenzylamino)-1-ethoxycarbonylamino-benzene;
2-Amino-4-benzylamino-1-ethoxycarbonylamino-benzene;
2-Amino-4-(3,5-dichlorobenzylamino)-1-ethoxycarbonylamino benzene;
2-Amino-4-(3,5-dichlorobenzylamino)-1-propyloxycarbonylamino
benzene; 2-Amino-(2-chlorobenzylamino)-1-(diethylcarbamoylamino)
benzene;
2-Amino-4-(2,4-dichlorobenzylamino)-1-(dimethylcarbamoylamino)
benzene; or 1,2-Diacetylamino-4-(4-fluorobenzylamino) benzene; or a
pharmaceutically acceptable salt thereof.
9. The method of Claim of claim 8 wherein the mammal is a
human.
10. The method of claim 8 wherein the mammal is feline or
canine.
11. The method of claim 8 wherein the hyperactive gastric motility
in a mammal is associated with inflammatory bowel disease.
12. The method of claim 8 wherein the hyperactive gastric motility
in a mammal is associated with Crohn's disease.
13. A method of treatment or inhibition of hyperactive gastric
motility in a mammal, the method comprising administering to a
mammal in need thereof a pharmacologically effective amount of
N-[2-amino-4-(4-fluorobenzylamino- )-phenyl]carbamic acid or a
pharmaceutically acceptable salt or ester form thereof.
14. The method of claim 13 wherein the pharmaceutically acceptable
ester form is N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic
acid ethyl ester.
15. The method of Claim of claim 13 wherein the mammal is a
human.
16. The method of claim 13 wherein the hyperactive gastric motility
in a mammal is associated with inflammatory bowel disease.
17. The method of claim 13 wherein the hyperactive gastric motility
in a mammal is associated with Crohn's disease.
18. A method of treatment or inhibition of hyperactive gastric
motility in a mammal, the method comprising administering to a
mammal in need thereof a pharmacologically effective amount of a
compound of the formula: 13wherein: R is hydrogen, hydroxy or
fluoro; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each are
independently hydrogen, C.sub.1-4 alkyl, halogen, trifluoromethyl,
phenyl, p-methylphenyl or p-trifluoromethylphenyl; or R.sup.1 and
R.sup.2, R.sup.2 and R.sup.3 or R.sup.3 and R.sup.4 are joined
together to form a benzo fused ring; R.sup.5 is hydrogen or
C.sub.1-4 alkyl; and R.sup.6 is chlorine or trifluoromethyl; or a
nontoxic pharmaceutically acceptable salt, solvate or hydrate
thereof..
19. The method of treatment or inhibition of hyperactive gastric
motility in a mammal of claim 18 wherein the compound is selected
from the group of:
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-(trifluor-
omethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-6-
-(trifluoromethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-
-dihydro-3-hydroxy-6-(trifluoromethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-(trifluoromethyl)-2H-in-
dol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-4,6-dichloro-1,3-dihydro-3--
hydroxy-2-H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-
-hydroxy-7-(trifluoromethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyp-
henyl)-1,3-dihydro-3-hydroxy-4-trifluoromethyl)2H-indol-2-one;
(.+-.)-1,3-Dihydro-3-hydroxy-3-[2-hydroxy-5-(trifluoromethyl)phenyl]-6-(t-
rifluoromethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-di-
hydro-3-hydroxy-4,6-bis(trifluoromethyl)-2H-indol-2-one;
(-)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-(trifluoromethyl-
)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydrox-
y-6-(trifluoromethyl)2H-indol-2-one;
(-)-3-(5-Chloro-2-hydroxyphenyl)-1,3--
dihydro-3-hydroxy-6-(trifluoromethyl)2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluorometh-
yl)2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydro-
xy-2H-benz[g]indol-2one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-
-phenyl-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-
-benz[g]indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-flu-
oro-6-phenyl-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihyd-
ro-3-fluoro-6-iodo-2H-indol-2one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3--
dihydro-6-(4-methylphenyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphe-
nyl)-1,3-dihydro-3-fluoro-7-(trifluoromethyl)-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-benz[e]indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-5-methyl-2H-indo-
l-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-4,6-bis(-
trifluoromethyl)-2H-indol-2-one;
(.+-.)-5-Bromo-3-(5-chloro-2-methoxypheny-
l)-1,3-dihydro-3-fluoro-2H-indol-2one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-
-1,3-dihydro-6-[4-(trifluoromethyl)phenyl]-2H-indol-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-indol-2-one;
(.+-.)-5-Bromo-3-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-2H-indo-
l-2-one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-4,6-dichloro-1,3-dihydro-2H-i-
ndol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-io-
do-2H-indol-2-one;
(.+-.)-3-(5-Chloro-hydroxyphenyl)-1,3-dihydro-6-iodo-2H-
-indol-2-one;
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-2H-
-benz[f]indol-2one;
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydr-
oxy-2H-benz[f]indol-2one; and
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihy-
dro-2H-benz[f]indol-2-one; and the pharmaceutically acceptable salt
forms thereof.
20. The method of Claim of claim 18 wherein the mammal is a
human.
21. The method of claim 18 wherein the mammal is feline or
canine.
22. The method of claim 18 wherein the hyperactive gastric motility
in a mammal is associated with inflammatory bowel disease.
23. The method of claim 18 wherein the hyperactive gastric motility
in a mammal is associated with Crohn's disease.
Description
[0001] This application claims priority from copending provisional
application Ser. No. 60/281,471, filed Apr. 4, 2001, the entire
disclosure of which is hereby incorporated by reference
[0002] This invention relates to novel methods for modulating
gastric tissues utilizing compounds which modulate the KCNQ family
of potassium channels, particularly compounds which open or agonize
the channels. The methods of this invention include the treatment,
prevention, inhibition and amelioration of hyperactive gastric
motility, including that associated with colitis, Irritable Bowel
Syndrome and Crohn's Disease.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 5,384,330 (Dieter et al.) teaches
pharmacologically active 1,2,4-triaminobenzene derivatives of the
General Formula: 1
[0004] and their properties as anti-epileptic, muscle relaxing,
fever-reducing and peripheral analgesic agents.
[0005] U.S. Pat. No. 5,565,483 (Hewawasam et al.) teaches compounds
of the formulae: 2
[0006] wherein: R is hydrogen, hydroxy or fluoro; R.sup.1, R.sup.2,
R.sup.3 and R.sup.4 each are independently hydrogen, C.sub.1-4
alkyl, halogen, trifluoromethyl, phenyl, p-methylphenyl or
p-trifluoromethylphenyl; or R.sup.1 and R.sup.2, R.sup.2 and
R.sup.3 or R.sup.3 and R.sup.4 are joined together to form a benzo
fused ring; R.sup.5 is hydrogen or C.sub.1-4 alkyl; and R.sup.6 is
chlorine or trifluoromethyl; or a nontoxic pharmaceutically
acceptable salt, solvate or hydrate thereof, which are potassium
channel openers useful for treating ischemia, convulsions and
asthma.
[0007] The article Modulation of KCNQ2/3 Potassium Channels by the
Novel Anticonvulsant Retigabine, Main et al., Molecular
Pharmacology, 58: pp. 253-262, 2000, describes the actions of
retigabine (D23129;
N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid ethyl
ester) in modulating the KCNQ2/3 potassium channels in oocytes in a
3-fold manner, i.e. retigabine shifts the voltage dependence of
channel activation to more hyperpolarized membrane potentials,
increases the rate of channel activation and slows channel
deactivation.
[0008] U.S. Pat. No. 5,849,789 and 5,852,053 (both to Rostock et
al.) teaches the use of retigabine for the treatment of
neurodegenerative disorders, including those associated with
stroke.
[0009] U.S. Pat. No. 5,914,425 (Meisel et al.) teaches novel
crystalline forms of retigabine.
[0010] U.S. Pat. No. 6,117,900 teaches the use of retigabine, also
known as N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid
ethyl ester, for the treatment of neuropathic pain.
DESCRIPTION OF THE INVENTION
[0011] This invention comprises methods for treating, preventing,
inhibiting, alleviating or controlling hyperactive gastric motility
in a mammal, the methods comprising administering to a mammal in
need thereof a pharmaceutically effective amount of a compound
which acts as an agonist or opener of the KCNQ family of potassium
channels, including the KCNQ2, KCNQ3, KCNQ4, and KCNQ5 potassium
channels, alone or in combination. A particular embodiment of this
invention includes use in the methods described herein of one or
more agonists or openers of KCNQ2/3 potassium channels. Another
series of methods of this invention comprises use of one or more
agonists or openers of KCNQ3/5 potassium channels. Further methods
of this invention comprise treatment of the bladder instability
conditions described herein by pharmaceutical administration of one
or more agonists or openers of KCNQ4 potassium channels.
[0012] Specific methods of this invention include the treatment,
prevention, inhibition, alleviation or control of hyperactive
gastric motility associated with colitis, irritable bowel syndrome
(IBS) or Crohn's Disease.
[0013] Among the compounds useful in the methods of this invention
are those disclosed in U.S. Pat. No. 5,384,330 (Dieter et al.), the
contents of which are incorporated herein by reference. The
compounds include those of the formula: 3
[0014] wherein:
[0015] R.sub.1 is selected from hydrogen, C.sub.1--C.sub.6-alkyl,
C.sub.2--C.sub.6-alkanoyl or the radical Ar;
[0016] R.sub.2 is selected from hydrogen or
C.sub.1--C.sub.6-alkyl;
[0017] R.sub.3 is selected from C.sub.1--.sub.6-alkoxy, NH.sub.2,
C.sub.1--C.sub.6-alkylamino, C.sub.1--C.sub.6-dialkylamino, amino
substituted by the radical Ar, C.sub.1--C.sub.6-alkyl,
C.sub.2--C.sub.6-alkenyl, C.sub.2--C.sub.6-alkynyl, the radical Ar
or the radical ArO--;
[0018] R.sub.4 is selected from hydrogen, C.sub.1--C.sub.6-alkyl or
the radical Ar;
[0019] R.sub.5 is selected from hydrogen or C.sub.1--C.sub.6-alkyl
or the radical Ar;
[0020] Alk indicates a straight or branched alkylene group with 1-9
carbon atoms, which can also be substituted by the radical Ar;
[0021] Ar is a phenyl radical substituted by the radicals R.sub.6,
R.sub.7 and/or R.sub.8 where these radicals R.sub.6, R.sub.7 and
R.sub.8 are the same or different and represent H,
C.sub.1--C.sub.6-alkyl, C.sub.3--C.sub.7-cycloalkyl, hydroxy,
C.sub.1--C.sub.6-alkoxy, C.sub.2--C.sub.6-alkanoyloxy, halogen,
hydroxy, C.sub.1--C.sub.6-halogeno- alkyl, --CN, --NH.sub.2,
--NH--C.sub.1--C.sub.6--alkyl, --N(C.sub.1--C.sub.6-alkyl).sub.2,
--CO.sub.2H, --CO--C.sub.1--C.sub.6-al- kyl,
--CO--O--C.sub.1--C.sub.6-alkyl, --COAr, --CO--OAr, --CONH.sub.2,
--CONH--C.sub.1--C.sub.6-alkyl,
--CON(C.sub.1--C.sub.6-alkyl).sub.2, --CONHAr,
--NH--CO--C.sub.1--C.sub.6-alkyl, --NHCO--Ar,
--NHCO--C.sub.1--C.sub.6-alkoxy, --N--H--CO--Ar, --NHCO--NH.sub.2,
--NHCO--N (--C.sub.1--C.sub.6-alkyl).sub.2, --NHCO--NHAr,
--NH--SO.sub.2--C--1--C.sub.6-alkyl, --NH--SO.sub.2Ar,
--NH--SO.sub.2-nitrophenyl, --SO.sub.2--OH,
--SO.sub.2--C.sub.1--C.sub.6-- alkyl, --SO.sub.2--Ar,
--SO.sub.2--C.sub.1--C.sub.6-alkoxy, --SO.sub.2--OAr,
--SO.sub.2--NH.sub.2, --SO.sub.2--NH--C.sub.1--C.sub.6-a- lkyl,
--SO.sub.2--N(C.sub.1--C.sub.6-alkyl).sub.2, --SO.sub.2--NHAr,
--SO.sub.2--C.sub.1--C.sub.6-alkoxy;
[0022] n is 0 or 1;
[0023] or a pharmaceutically acceptable salt thereof.
[0024] The alkyl groups, halogenalkyl groups, alkenyl groups,
alkynyl groups, alkoxy groups, alkylamino groups, alkanoyl amino
groups, alkanoyloxy groups and alkanoyl groups in general can be
straight or branched. The same also applies to alkyl and alkyloxy
groups (=alkoxy groups) if these are components of more complicated
radicals for example in the form of a monoalkyl- or dialkylamino
group, alkanoylamino group, carbalkoxy group, alkylcarbonyl group
and analogous groups. The C.sub.3--C.sub.7-cycloalkyl group is
preferably cyclopentyl or cyclohexyl. C.sub.2--C.sub.6-alkenyl
preferably represents allyl. C.sub.2--C.sub.6-alkynyl preferably
represents propargyl.
[0025] The halogen atoms are chlorine, bromine or fluorine, in
particular chlorine of fluorine. The alkyl and alkoxy groups as
such or as components of groups of more complicated radicals
consist in particular of 1-4 carbon atoms, preferably 1 or 2 carbon
atoms. Alkanoyl groups, such as alkanoylamino groups or alkanoyloxy
groups consist in particular of 2-4, preferably 2-3 carbon atoms.
Alk consists in particular of 1-3, preferably 1 or 2 carbon
atoms.
[0026] Among the more preferred compounds of this group are:
[0027] 2-Amino-4-(4-fluorobenzylamino)-1
-ethoxycarbonylaminobenzene;
[0028] 2-Amino-4-(4-trifluoromethylbenzylamino)-1
-ethoxycarbonylamino-ben- zene;
[0029] 2-Amino-4-benzylamino-1 -ethoxycarbonylamino-benzene;
[0030] 2-Amino-4-(3,5-dichlorobenzylamino)-1 -ethoxycarbonylamino
benzene;
[0031] 2-Amino-4-(3,5-dichlorobenzylamino)-1
-propyloxycarbonylamino benzene;
[0032] 2-Amino-(2-chlorobenzylamino)-1-(diethylcarbamoylamino)
benzene;
[0033]
2-Amino-4-(2,4-dichlorobenzylamino)-1-(dimethylcarbamoylamino)
benzene; and
[0034] 1 ,2-Diacetylamino-4-(4-fluorobenzylamino) benzene;
[0035] Among the most preferred compounds for use in the methods of
this invention are
N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid and its
pharmaceutically acceptable salts and ester forms. Of particular
preference is retigabine, also known as
N-[2-amino-4-(4-fluorobenzylamino- )-phenyl]carbamic acid ethyl
ester (CAS Registry No. 150812-12-7), having the formula: 4
[0036] Also useful in the methods of this invention are the
metabolite forms of retigabine which may be isolated from blood,
urine or feces of recipients of
N-[2-amino-4-(4-fluorobenzylamino)-phenyl]carbamic acid ethyl
ester. The metabolites include the glucoside of retigabine,
[4-(4-Fluoro-benzylamino)-2-(3,4,5-trihydroxy-6-hydroxymethyl-tetrahydrop-
yran-2-ylamino)-phenyl]-carbamic acid ethyl ester, as well as its
two glucoronide analogs,
6-[2-Ethoxycarbonylamino-5-(4-fluoro-benzylamino)-ph-
enylamino]-3,4,5-trihydroxy-tetrahydro-pyran-2-carboxylic acid and
6-[(3-Amino-4-ethoxycarbonylamino-phenyl)-(4-fluoro-benzyl)-amino]-3,4,5--
trihydroxy-tetrahydro-pyran-2-carboxylic acid. Further metabolites
include N-[2-Amino-4-(4-fluoro-benzylamino)-phenyl]acetamide, its
cyclized analog
(4-Fluoro-benzyl)-2-methyl-1H-benzoimidazol-5-yl)amine and the
glucoronide analogs of
N-[2-Amino-4-(4-fluoro-benzylamino)-phenyl]acetami- de,
6-[(4-Acetylamino-3-amino-phenyl)-(4-fluoro-benzyl)-amino]-3,4,5-trihy-
droxy-tetrahydro-pyran-2-carboxylic acid and
6-[2-Acetylamino-5-(4-fluoro--
benzylamino)-phenylamino]-3,4,5-trihydroxy-tetrahydro-pyran-2-carboxylic
acid.
[0037] Also useful in the methods of this invention are the
substituted 3-phenyl oxindole compounds disclosed in U.S. Pat. No.
5,565,483 (Hewawasam et al.), which issued on Oct. 15, 1996, the
contents of which are incorporated herein by reference. These
compounds include the substituted 3-phenyl oxindole compounds
having the formulae: 5
[0038] wherein:
[0039] R is hydrogen, hydroxy or fluoro;
[0040] R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each are independently
hydrogen, C.sub.1-4 alkyl, halogen, trifluoromethyl, phenyl,
p-methylphenyl or p-trifluoromethylphenyl; or R.sup.1 and R.sup.2,
R.sup.2 and R.sup.3 or R.sup.3 and R.sup.4 are joined together to
form a benzo fused ring;
[0041] R.sup.5 is hydrogen or C.sub.1-4 alkyl; and
[0042] R.sup.6 is chlorine or trifluoromethyl;
[0043] or a nontoxic pharmaceutically acceptable salt, solvate or
hydrate thereof..
[0044] One group of the substituted 3-phenyl oxindole compounds
useful with this invention include those described above wherein R
is hydrogen. Another subgroup of these compounds include those in
which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently
selected from H, C.sub.1 to C.sub.4 alkyl, halogen or
trifluoromethyl, and when R.sup.1 and R.sup.4 are H; R.sup.2 or
R.sup.3 is phenyl, p-methoxyphenyl or trifluormethylphenyl; or
R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, or R.sup.3 and R.sup.4
are joined together to form a benzo fused ring; R5 is H or C.sub.1
to C.sub.4 alkyl; and R.sup.6 is chlorine or trifluoromethyl, or a
pharmaceutically acceptable salt form thereof.
[0045] Non-limiting examples of these substituted 3-phenyl oxindole
compounds are:
[0046]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-(triflu-
oromethyl)-2H-indol-2-one;
[0047]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-6-(trifluoromethyl)-
-2H-indol-2-one;
[0048]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-6-(triflu-
oromethyl)-2H-indol-2-one;
[0049]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-(trifluoromethyl)-
-2H-indol-2-one;
[0050]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-4,6-dichloro-1,3-dihydro-3-hydr-
oxy-2-H-indol-2-one;
[0051]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-7-(triflu-
oromethyl)-2H-indol-2-one;
[0052]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-4-trifluo-
romethyl)2H-indol-2-one;
[0053]
(.+-.)-1,3-Dihydro-3-hydroxy-3-[2-hydroxy-5-(trifluoromethyl)phenyl-
]-6-(trifluoromethyl)-2H-indol-2-one;
[0054]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-4,6-bis(t-
rifluoromethyl)-2H-indol-2-one;
[0055]
(-)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-(trifluoro-
methyl)-2H-indol-2-one;
[0056]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-6-(triflu-
oromethyl)2H-indol-2-one;
[0057]
(-)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-6-(trifluoro-
methyl)2H-indol-2-one;
[0058]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluo-
romethyl)2H-indol-2-one;
[0059]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-2H-benz[g-
]indol-2one;
[0060]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-phenyl-2H-indol-2-
-one;
[0061]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-benz[g]indol-2-o-
ne;
[0062]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-phenyl-2-
H-indol-2-one;
[0063]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-iodo-2H--
indol-2one;
[0064]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-(4-methylphenyl)--
2H-indol-2-one;
[0065]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-7-(trifluo-
romethyl)-2H-indol-2-one;
[0066]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-benz[e]indol-2-o-
ne;
[0067]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-5-methyl-2-
H-indol-2-one;
[0068]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-4,6-bis(tr-
ifluoromethyl)-2H-indol-2-one;
[0069]
(.+-.)-5-Bromo-3-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-2H-
-indol-2one;
[0070]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-[4-(trifluorometh-
yl)phenyl]-2H-indol-2-one;
[0071]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-indol-2-one;
[0072]
(.+-.)-5-Bromo-3-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-2-
H-indol-2-one;
[0073]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-4,6-dichloro-1,3-dihydro-2H-ind-
ol-2-one;
[0074]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-hydroxy-6-iodo-2H-
-indol-2-one;
[0075]
(.+-.)-3-(5-Chloro-hydroxyphenyl)-1,3-dihydro-6-iodo-2H-indol-2-one-
;
[0076] (.+-.)-3-(5-Chloro-2-methoxyphenyl)-
1,3-dihydro-3-hydroxy-2H-benz[- f]indol-2one;
[0077]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-2H-benz[f-
]indol-2one; and
[0078]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-benz[f]indol-2-o-
ne;
[0079] and the pharmaceutically acceptable salt forms thereof.
[0080] Among the more preferred compounds of this group are: 6
[0081]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-(trifluoromethyl)-
-2H-indol-2-one; 7
[0082]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-6-(triflu-
oromethyl)-2H-indol-2-one; 8
[0083]
(.+-.)-3-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluo-
romethyl)-2H-indol-2-one; 9
[0084]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-3-hydroxy-2H-benz[g-
]indol-2-one; 10
[0085]
(+)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-6-phenyl-2H-indol-2-on-
e; and 11
[0086]
(.+-.)-3-(5-Chloro-2-hydroxyphenyl)-1,3-dihydro-2H-benz[e]indol-2-o-
ne.
[0087] Pharmaceutically acceptable salt forms of these substituted
3-phenyl oxindole compounds include those formed as base addition,
including those formed using suitable inorganic bases, such as
alkali and alkaline earth metal bases, such as sodium, potassium,
magnesium and calcium metallic cations. The compounds may be
administered as described in U.S. Pat. No. 5,565,483. A
pharmaceutically effective amount in mammals, including man, may be
from about 0.1 pg/kg to about 100 mg/kg of body weight. Parenteral
administration may be completed at an effective dose of from about
1 pg/kg to about 10 mg/kg of body weight.
[0088] The methods of this invention are useful for treating,
preventing, inhibiting or ameliorating hyperactive gastric motility
in a mammal, the methods each comprising administering to a mammal
in need of such treatment a pharmaceutically effective amount of a
KCNQ potassium channel opener, as described above. The conditions
which may be treated with the methods of this invention include
irritable bowel syndrome, also known as spastic colon, Crohn's
Disease and mucous colitis. The methods of this invention may also
be used for mammalian gastrointestinal (GI) conditions including
diarrhea, chronic diarrhea, acute diarhea, abdominal pain
associated with diarrhea, postprandial urgency, postprandial
accentuation of diarrhea or abdominal pain, or a combination of two
or more of these symptoms.
[0089] Irritable Bowel Syndrome (IBS) is part of a spectrum of
diseases known as Functional Gastrointestinal Disorders, which
include diseases such as noncardiac chest pain, nonulcer dyspepsia,
and chronic constipation or diarrhea. It has also been referred to
as spastic colon, nervous colitis, mucous colitis, functional
colitis or colonic neurosis. As no diagnostic marker is currently
associated with IBS, the diagnosis is one of exclusion based on
symptoms. Manning et al. first reported six symptoms which
differentiated IBS from other gastrointestinal diseases. These
criteria have become art recognized in the diagnosis of IBS, see
Gut 1990;31:77-81; Olibuyide et al., Dig Dis Sci 1995; 40:983-5;
Rao et al., J Assoc Physician India 1993;41:357-8; and Jeong et al.
Korean J. Intern. Med. 1993;8:34-9. The six `Manning Criteria` are:
a) relief of abdominal pain with defecation, b) looser stools with
the onset of pain, c) more frequent bowel movements at onset of
pain, d) abdominal bloating or distention, e) feelings of
incomplete evacuation, and f) passage of mucus per rectum.
Generally speaking, the more `Manning Criteria` present the more
likely an indication of IBS.
[0090] The compounds and methods of this invention may be used in
conjunction with laxatives and anti-diarrheal medications
frequently used for the treatment or amelioration of symptoms of
IBS. In patients with abdominal cramps, antispasmodic drugs, such
as dicyclomine, may be used with the methods herein. It will also
be understood that the KCNQ channel opening compounds of this
invention may be administered in conjunction with conventional drug
therapies for IBS, including opioid agonists such as loperamide or
anticholinergic agents, such as pepenzolate bromide or timepidium
bromide to control gastrointestinal hypermotility. In cases where
anxiety or related conditions increase the likelihood or severity
of symptoms, anti-anxiety agents may be co-employed. These include
those known in the art, but not limited to venlafaxine HCl,
diazepam, fluoxetine HCl, hydroxyzine HCl, hydroxyzine pamoate,
mephobarbital, meprobamate, paroxetine HCI, doxepin HCI, lorazepam,
chlordiazepoxide HCl, alone or in combination with amitryptyline
HCl, clorazepate dipotassium, or alprazolam. Each of these
medicaments may be administered in the conventional methods and
administrations known in the art, including those described in the
Physicians' Desk Reference 2001, 55 Edition, published by Medical
Economics Company, Inc. at Montvale, N.J. 07645-1742.
[0091] At the recommendation of a medical professional,
non-medication and lifestyle changes may also be recommended for
IBS sufferers, including an increase in fiber intake (dietary or
fiber supplements) to help relieve constipation and cramps.
[0092] Crohn's disease involves chronic inflammation of the
intestines with symptoms including abdominal pain, diarrhea, and
weight loss. Less common symptoms include poor appetite, fever,
night sweats, rectal pain, and rectal bleeding. Crohn's disease may
affect the colon, the rectum, and the small intestine and, in rare
instances, also the stomach, mouth, and esophagus. Crohn's colitis
is inflammation that appears only in the colon, often involving
abdominal pain and bloody diarrhea. Anal fistulae and perirectal
abscesses can also occur. Crohn's enteritis is inflammation
confined to the small intestine. Crohn's terminal ileitis is
inflammation that affects the end of the small intestine (terminal
ileum). Crohn's enterocolitis and ileocolitis involves inflammation
of both the small intestine and the colon. Crohn's terminal ileitis
and ileocolitis are the most common types of Crohn's disease.
Abdominal pain and diarrhea often result in each type of Crohn's
disease. The compounds and methods of this invention may be used to
treat, inhibit, prevent or ameliorate each of these Crohn's
conditions.
[0093] The compounds of this invention may also be used in
combination therapies or regimens with medications conventionally
used to treat Crohn's disease and its symptoms including anti-
inflammatory agents, such as 5-ASA compounds, systemic
corticosteorids, topical corticosteroids, and antibiotics, as well
as immunomodulators. Anti-inflammatory agents which are effective
in treating Crohn's disease include corticosteroids and the 5-
aminosalycylates (5-ASA) compounds. Examples of corticosteroids
include Prednisone, Prednisolone, and Budesonide. Examples of 5-ASA
compounds include ASACOL.RTM. brand mesalamine, PENTASA.RTM. brand
mesalamine controlled release capsules, and ROWASA.RTM. brand
mesalamine rectal suspensions enema. Antibiotics may be used in
conjunction to the potassium channel openers of this invention for
treating Crohn's colitis, such as metronidazole (available as
FLAGLYL.RTM. brand metronidazole tablets or FLAGLYL.RTM. ER brand
extended release metronidazole tablets) and ciprofloxacin. Examples
of useful immunomodulators include 6-mercaptopurine (6-MP),
azathioprine, methotrexate, and anti-TNF-alpha (REMICADE.RTM.
infliximab recombinant for IV injection).
[0094] In cases where diseased portions of the intestines are
surgically removed Crohn's disease may eventually return to
previously healthy tissue. The KCNQ potassium channel openers of
this invention may be used in conjunction with medications such as
mesalamine or 6-mercaptopurine (6-MP) to reduce the chances of
Crohn's disease relapse after surgery or limit the severity of such
relapses.
[0095] In relevant diarrhea-related conditions, a medical
professional may also use the KCNQ channel openers of this
invention in combination with an inhibitor of gastric secretion,
such as a proton pump inhibitor, a histamin H.sub.2-receptor
blocker, omeprazole, lansoprazole, cimetidine, ranitidine,
nizatidine, or famotidine.
[0096] Pharmaceutically effective amounts of the KCNQ channel
opening compounds described herein may also be used to inhibit,
limit or delay defecation in a mammal in need of such treatment.
This may be used to inhibit or control anal incontinence in a
mammal, including humans, who experience a lessened ability to
control bowel movements or experience or are susceptible to anal
incontinence. These methods include effecting a desirable delay or
inhibition of postprandial urgency or postprandial intestinal
cramping or related pain.
[0097] The methods of this invention are useful for inducing or
assisting in control or prevention or treatment of the maladies
described herein in humans in need of such relief, including adult
and pediatric uses. However, they may also be utilized for
veterinary applications, particularly including canine and feline
fecal control methods. If desired, the methods herein may also be
used with farm animals, such as ovine, bovine, porcine and equine
breeds.
[0098] The applications may utilize conventional oral, rectal,
parenteral or intravenous delivery methods as conventionally
utilized in veterinary practice. Most preferable in most instance
for home use with companion animals are oral tablets or capsules or
neat compound or powdered or granular pharmaceutical formulations
which may be mixed with chewable or liquid veterinary formulations
or food materials or liquids acceptable to the animal in
question.
[0099] As used herein, the terms "pharmaceutically effective
amount" or "therapeutically effective amount" mean the total amount
of each active component of the pharmaceutical composition or
method that is sufficient to show a meaningful patient benefit,
i.e., treatment, prevention or amelioration of hyperactive gastric
motility or the excessive or undesirable urge to defecate, or a
decrease in the frequency of incidence of fecal incontinence. When
the malady in question warrants, a pharmaceutically or
therapeutically effective dose may be considered the minimal amount
of the compound in question which will alleviate, inhibit or remove
the cramping, pressure, pain or feeling of fecal urgency associated
with hyperactive gastric motility. When applied to an individual
active ingredient, administered alone, the term refers to that
ingredient alone. When applied to a combination, the term refers to
combined amounts of the active ingredients that result in the
therapeutic effect, whether administered in combination, serially
or simultaneously.
[0100] The methods of this invention may be accomplished with a
daily dose of the active compounds described above from U.S. Pat.
No. 5,384,330 of from about 0.1 mg/kg to about 10 mg/kg. Doses may
be administered as a single regimen, such as only prior to bedtime
or before travel, or as a continuous regimen divided by two or more
doses over the course of a day. Human administration may be at
dosages of from about 10 mg BID to about 1000 mg BID, preferably
from about 50 mg BID to about 500 mg BID, more preferably at a dose
of from about 100 mg BID to about 300 mg BID.
[0101] Compounds as described in U.S. Pat. No. 5,384,330, including
retigabine, can be administered orally using conventional
pharmaceutical excipients or carriers, preferably coated or
contained in hard or soft gelatin capsules. Examples of oral
formulations contained in hard gelatin capsules can include those
in which the active compound comprises from about 45% to 50%, by
weight, of the formulation. Microcrystalline cellulose comprises
from about 43% to about 47%, povidone comprises from about 3% to
about 4%, and silicon dioxide and magnesium stearate each comprise
from about 0.3% to about 0.7%, each by weight. Specific examples of
capsules containing 50 mg, 100 mg and 200 mg may be formulated
utilizing the following lists of components.
1 Ingredient Amount/Capsule 50 mg Retigabine Capsules Retigabine
50.0 mg Microcrystalline Cellulose, NF 45.5 mg Povidone, USP 3.5 mg
Silicon Dioxide, Colloidal, anhydrous, NF 0.5 mg Magnesium
Stearate, EP 0.5 mg Theoretical Fill Weight 100 mg 100 mg
Retigabine Capsules Retigabine 100.0 mg Microcrystalline Cellulose,
NF 91.0 mg Povidone, USP 7.0 mg Silicon Dioxide, Colloidal,
anhydrous, NF 1.0 mg Magnesium Stearate, EP 1.0 mg Theoretical Fill
Weight 200 mg 200 mg Retigabine Capsules Retigabine 200.0 mg
Microcrystalline Cellulose, NF 182.0 mg Povidone, USP 14.0 mg
Silicon Dioxide, Colloidal, anhydrous, NF 2.0 mg Magnesium
Stearate, EP 2.0 mg Theoretical Fill Weight 400 mg
[0102] The ingredients in the formulations above can be prepared
using the following steps.
[0103] 1 ) Weigh separately the active ingredient (retigabine),
preferably screened through an 800 micron screen, and the
microcrystalline cellulose components.
[0104] 2) Prepare a granulation solution by dissolving the
Povidone, USP in purified water.
[0105] 3) Place the ingredients from Step 1 into a suitable blender
and mix thoroughly.
[0106] 4) Screen the mixture from Step 3 through a 1000 .mu.m
screen and place the screened mixture into the vessel of a
fluidized bed granulator.
[0107] 5) Heat the ingredients in the fluid bed granulator up to
27.degree. C. product temperature while mixing.
[0108] 6) Add the granulation solution from Step 2 to the fluid
bed.
[0109] 7) Dry the granulate in the fluid bed.
[0110] 8) Weigh the colloidal silicon dioxide component, preferably
screened through a 1000 .mu.m screen, and the magnesium stearate
component, preferably screened through a 600 .mu.m screen. 9) Add
the silicon dioxide and magnesium stearate components to the fluid
bed granulator's vessel containing the dried granulate from Step 7
and mix the components thoroughly.
[0111] 10) Screen the mixed components from Step 9, preferably
through a 800 .mu.m screen.
[0112] 11) Transfer the final screened components into a suitable
blender and mix thoroughly.
[0113] The final component mixture from Step 11 can then be coated,
encapsulated or compressed into tablets utilizing conventional
tablet excipients or carriers, as desired. It will be understood
that oral dosage forms within the scope of this invention can be
prepared using the components listed above in respective amounts
according the dose of active ingredient in the particular
formulation. For veterinary uses, the final mixture of Step 11 can
be administered neat or mixed into foods acceptable to the animal
in question. Further, the mixtures can be formulated into tablets,
capsules or coated products, as described above, or integrated into
conventional veterinary medicaments or food products.
[0114] For intravenous administration, the compounds from U.S. Pat.
No. 5,384,330 described herein may be prepared and maintained in
conventional lyophylized formulations and reconstituted prior to
administration with an intravenously acceptable saline solution,
such as a 0.9% saline solution. The pH of the intravenous
formulation can be adjusted, as needed, with an intravenous and
pharmaceutically acceptable acid, such as methanesulfonic acid.
[0115] The following demonstrates the ability of retigabine to open
KCNQ potassium channels in mammalian tissue.
[0116] KNCQ1, 3 and 5 expression and M-current activity in rat
urinary bladder
[0117] Using quantitative rtPCR, the expression of KCNQ1, KCNQ3 and
KCNQ5 potassium channels was identified in the rat urinary bladder.
The highest levels of expression were seen in KCNQ5 (0.2.+-.0.1 ng
KCNQ5 mRNA/GAPDH mRNA). To further probe M-current activity in the
bladder, retigabine (10 .mu.M, M-current agonist) was tested in
isolated bladder smooth muscle cells using standard patch-clamp
techniques. Exposure to retigabine significantly increased an
outward current that was insensitive to iberiotoxin and was
associated with a membrane hyperpolarization of 17.8.+-.3.0 mV
(n=5). This hyperpolarization was reversed by the addition of
linopirdine (50 .mu.M an M-current antagonist) to the tissue bath.
Retigabine relaxed isolated carbachol contracted rat bladder strips
with an IC.sub.50 of 3.5.+-.0.9 .mu.M (n=14). This relaxation was
reversed by the M-current blockers linopirdine and XE-991.
[0118] KCNQ potassium channel activity in guinea pig ileum
[0119] Following the procedures of the previous example, the
effects of retigabine on isolated precontracted guinea pig ileum
preparations were studied. Sections of ileum were isolated from
male guinea pigs and suspended in a tissue bath. One end of the
tissue was anchored to the bottom of the bath, and the other end to
a force transducer. Tissues were contracted with either 20 mM KCl
or 200 nM carbachol. The KCNQ channel agonist retigabine was added
to the tissue baths in increasing concentrations. Retigabine
produced a concentration-dependent inhibition of contraction as
follows:
2 KCI Contracted IC.sub.50 = 7.1 .+-. 2 Carbarchol Contracted
IC.sub.50 = 5.4 .+-. 2
[0120] Both responses to retigabine were antagonized by the KNCQ
channel blocker XE-991.
* * * * *