Potassium channel blockers are agents which interfere with conduction through
potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of cel ...
s.
Medical uses
Arrhythmia
Potassium channel blockers used in the treatment of
cardiac arrhythmia
Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults ...
are classified as class III antiarrhythmic agents.
Mechanism
Class III agents predominantly block the potassium channels, thereby prolonging repolarization.
More specifically, their primary effect is on
IKr.
Since these agents do not affect the
sodium channel
Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily of cation channels and can be classified according to the trigger that opens the channel ...
, conduction velocity is not decreased. The prolongation of the action potential duration and refractory period, combined with the maintenance of normal conduction velocity, prevent re-entrant arrhythmias. (The re-entrant rhythm is less likely to interact with tissue that has become refractory).
Examples and uses
*
Amiodarone
Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrilla ...
is indicated for the treatment of refractory
VT or
VF, particularly in the setting of acute ischemia. Amiodarone is also safe to use in individuals with
cardiomyopathy
Cardiomyopathy is a group of diseases that affect the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. A ...
and
atrial fibrillation, to maintain normal sinus rhythm. Amiodarone prolongation of the action potential is uniform over a wide range of heart rates, so this drug does not have reverse use-dependent action.
Amiodarone
Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrilla ...
was the first agent described in this class. Amiodarone should only be used to treat adults with life-threatening ventricular arrhythmias when other treatments are ineffective or have not been tolerated.
*
Dofetilide
Dofetilide is a class III antiarrhythmic agent. It is marketed under the trade name Tikosyn by Pfizer, and is available in the United States in capsules containing 125, 250, and 500 µg of dofetilide. It is not available in Europe or Australia. I ...
blocks only the rapid K channels; this means that at higher heart rates, when there is increased involvement of the slow K channels, dofetilide has less of an action potential-prolonging effect.
*
Sotalol
Sotalol, sold under the brand name Betapace among others, is a medication used to treat and prevent abnormal heart rhythms. It is only recommended in those with significant abnormal heart rhythms due to potentially serious side effects. Evidence ...
is indicated for the treatment of atrial or ventricular tachyarrhythmias, and
AV re-entrant arrhythmias.
*
Ibutilide
Ibutilide is a Class III antiarrhythmic agent that is indicated for acute cardioconversion of atrial fibrillation and atrial flutter of a recent onset to sinus rhythm. It exerts its antiarrhythmic effect by induction of slow inward sodium current ...
is the only antiarrhythmic agent currently approved by the
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
for acute conversion of
atrial fibrillation to sinus rhythm.
*
Azimilide
*
Bretylium
Bretylium (also bretylium tosylate) is an antiarrhythmic agent. It blocks the release of noradrenaline from nerve terminals. In effect, it decreases output from the peripheral sympathetic nervous system. It also acts by blocking K+ channels and is ...
*
Clofilium
Clofilium is an antiarrhythmic agent.
Quaternary ammonium compounds
Antiarrhythmic agents
Chloroarenes
{{organic-compound-stub ...
*
E-4031
E-4031 is an experimental class III antiarrhythmic drug that blocks potassium channels of the hERG-type.
Chemistry
E-4031 is a synthetized toxin that is a methanesulfonanilide class III antiarrhythmic drug.
Target
E-4031 acts on a specif ...
*
Nifekalant
*
Tedisamil
Tedisamil (3,7-dicyclopropylmethyl-9,9-tetramethylene-3,7-diazabicyclo-3,3,1-nonane) is an experimental class III antiarrhythmic agent currently being investigated for the treatment of atrial fibrillation. Tedisamil blocks multiple types of pota ...
*
Sematilide
Sematilide is an antiarrhythmic agent
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormally fast rhythms ( tachycardias), such as atrial fibrillation, suprave ...
Side effects
These agents include a risk of
torsades de pointes
''Torsades de pointes, torsade de pointes'' or ''torsades des pointes'' (TdP) (, , translated as "twisting of peaks") is a specific type of abnormal heart rhythm that can lead to sudden cardiac death. It is a polymorphic ventricular tachycardia t ...
.
Anti-diabetics
Sulfonylureas, such as
gliclazide
Gliclazide, sold under the brand name Diamicron among others, is a sulfonylurea type of anti-diabetic medication, used to treat type 2 diabetes. It is used when dietary changes, exercise, and weight loss are not enough. It is taken by mouth.
...
, are
ATP-sensitive potassium channel
An ATP-sensitive potassium channel (or KATP channel) is a type of potassium channel that is gated by intracellular nucleotides, ATP and ADP. ATP-sensitive potassium channels are composed of Kir6.x-type subunits and sulfonylurea receptor (SUR) ...
blockers.
Other uses
Dalfampridine, A potassium channel blocker has also been approved for use in the treatment of
multiple sclerosis
Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
.
Reverse use dependence
Potassium channel blockers exhibit reverse use-dependent prolongation of the action potential duration. Reverse use dependence is the effect where the efficacy of the drug is reduced after repeated use of the tissue.
This contrasts with (ordinary) use dependence, where the efficacy of the drug is increased after repeated use of the tissue.
Reverse use dependence is relevant for potassium channel blockers used as class III antiarrhythmics. Reverse use dependent drugs that slow heart rate (such as
quinidine
Quinidine is a class I antiarrhythmic agent, class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of Antimalarial medication, antimalarial agent quinine, originally derived from the bark of the cinchona tre ...
) can be less effective at high heart rates.
The
refractoriness of the ventricular
myocyte
A muscle cell is also known as a myocyte when referring to either a cardiac muscle cell (cardiomyocyte), or a smooth muscle cell as these are both small cells. A skeletal muscle cell is long and threadlike with many nuclei and is called a muscl ...
increases at lower
heart rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...
s. This increases the susceptibility of the myocardium to
early Afterdepolarizations
Early may refer to:
History
* The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.:
** Early Christianity
** Early modern Europe
Places in the United States
* Early, Iowa
* Early, Texas
* Early ...
(EADs) at low heart rates. Antiarrhythmic agents that exhibit reverse use-dependence (such as
quinidine
Quinidine is a class I antiarrhythmic agent, class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of Antimalarial medication, antimalarial agent quinine, originally derived from the bark of the cinchona tre ...
) are more efficacious at preventing a tachyarrhythmia than converting someone into normal sinus rhythm. Because of the reverse use-dependence of class III agents, at low heart rates class III antiarrhythmic agents may paradoxically be more arrhythmogenic.
Drugs such as quinidine may be both reverse use dependent and use dependent.
Calcium-activated channel blockers
Examples of
calcium-activated channel blockers include:
*
Charybdotoxin
Charybdotoxin (CTX) is a 37 amino acid neurotoxin from the venom of the scorpion '' Leiurus quinquestriatus hebraeus'' (''deathstalker'') that blocks calcium-activated potassium channels. This blockade causes hyperexcitability of the nervous syst ...
*
Iberiotoxin
Iberiotoxin (IbTX) is an ion channel toxin purified from the Eastern Indian red scorpion ''Hottentotta tamulus''.
Iberiotoxin selectively inhibits the current through large-conductance calcium-activated potassium channels.
Chemistry
Iberiotoxin ...
*
Apamin
Apamin is an 18 amino acid globular peptide neurotoxin found in apitoxin ( bee venom). Dry bee venom consists of 2–3% of apamin. Apamin selectively blocks SK channels, a type of Ca2+-activated K+ channel expressed in the central nervous syste ...
*
Kaliotoxin
{, style="float: right; clear: right; margin: 0 0 0.5em 1em; background: #ffffff;" class="toccolours" border="0" cellpadding="1" align="right" width="280"
!The amino acid sequence of Kaliotoxin
, -
, bgcolor="#eeeeee" , N - Gly - Val - Glu - Ile ...
,
*
Lolitrem,
*
BKCa-specific
**
GAL-021
**
Ethanol (alcohol)
Inwardly rectifying channel blockers
Examples of
inwardly rectifying channel blockers include:
ROMK
The renal outer medullary potassium channel (ROMK) is an ATP-dependent potassium channel (Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion ...
(K
ir1.1)
Nonselective:
Ba2+,
Cs+
GPCR regulated (Kir3.x)
*
GPCR
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...
antagonists
*
Ifenprodil
Ifenprodil is an inhibitor of the NMDA receptor, specifically of GluN1 (glycine-binding NMDA receptor subunit 1) and GluN2B (glutamate-binding NMDA receptor subunit 2) subunits. Additionally, ifenprodil inhibits GIRK channels, and interacts with a ...
*
Caramiphen
*
Cloperastine
Cloperastine (INN) or cloperastin, in the forms of cloperastine hydrochloride ( JAN) (brand names Hustazol, Nitossil, Seki) and cloperastine fendizoate (or hybenzoate), is an antitussive and antihistamine that is marketed as a cough suppressant ...
*
Clozapine
Clozapine is a psychiatric medication and is the first atypical antipsychotic (also called second-generation antipsychotic). It is primarily used to treat people with schizophrenia and schizoaffective disorders who have had an inadequate respo ...
*
Dextromethorphan
Dextromethorphan (DXM) is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms. In 2022, the FDA approved a formulation of it combined with bu ...
*
Ethosuximide
Ethosuximide, sold under the brand name Zarontin among others, is a medication used to treat absence seizures. It may be used by itself or with other antiseizure medications such as valproic acid. Ethosuximide is taken by mouth.
Ethosuximide i ...
*
Tertiapin Tertiapin is a 21-amino acid peptide isolated from venom of the European honey bee (''Apis mellifera''). It blocks two different types of potassium channels, inward rectifier potassium channels (Kir) and calcium activated large conductance potassi ...
*
Tipepidine
Tipepidine (INN) (brand names Asverin, Antupex, Asvelik, Asvex, Bitiodin, Cofdenin A, Hustel, Nodal, Sotal), also known as tipepidine hibenzate ( JAN), is a synthetic, non-opioid antitussive and expectorant of the thiambutene class. It acts as a ...
*
Ba2+
ATP-sensitive (Kir6.x)
*
Meglitinide
Meglitinides or glinides are a class of drugs used to treat type 2 diabetes.
Drugs
Repaglinide (trade name Prandin) gained US Food and Drug Administration approval in 1997.
Other drugs in this class include nateglinide (Starlix) and mitiglinid ...
s (Non-
Sulfonylurea
Sulfonylureas (UK: sulphonylurea) are a class of organic compounds used in medicine and agriculture, for example as antidiabetic drugs widely used in the management of diabetes mellitus type 2. They act by increasing insulin release from the beta ...
s)
**
Mitiglinide
Mitiglinide (INN, trade name Glufast) is a drug for the treatment of type 2 diabetes.
Mitiglinide belongs to the meglitinide (glinide) class of blood glucose-lowering drugs and is currently co-marketed in Japan by Kissei and Takeda. The North Ame ...
**
Nateglinide
Nateglinide (INN, trade name Starlix) is a drug for the treatment of type 2 diabetes. Nateglinide was developed by Ajinomoto, a Japanese company and sold by the Swiss pharmaceutical company Novartis.
Nateglinide belongs to the meglitinide class ...
**
Repaglinide
Repaglinide is an antidiabetic drug in the class of medications known as meglitinides, and was invented in 1983. Repaglinide is an oral medication used in addition to diet and exercise for blood sugar control in type 2 diabetes mellitus. The mech ...
*
Sulfonylurea
Sulfonylureas (UK: sulphonylurea) are a class of organic compounds used in medicine and agriculture, for example as antidiabetic drugs widely used in the management of diabetes mellitus type 2. They act by increasing insulin release from the beta ...
s
**
Acetohexamide
Acetohexamide (trade name Dymelor) is a first-generation sulfonylurea medication used to treat diabetes mellitus type 2, particularly in people whose diabetes cannot be controlled by diet alone.
Mechanism of action
Acetohexamide bind to an AT ...
**
Carbutamide
Carbutamide (brand name Glucidoral) is an anti-diabetic drug of the sulfonylurea class, developed by Servier.
It is classified as first-generation.
It was patented in 1953 and approved for medical use in 1956.
See also
* Hellmuth Kleinsorge
...
**
Chlorpropamide
Chlorpropamide is a drug in the sulfonylurea class used to treat diabetes mellitus type 2. It is a long-acting first-generation sulfonylurea.
Mechanism of action
Like other sulfonylureas, chlorpropamide acts to increase the secretion of insulin, ...
**
Glycyclamide
**
Metahexamide
Metahexamide ( INN) is an anti-diabetic drug from the group of sulfonylurea
Sulfonylureas (UK: sulphonylurea) are a class of organic compounds used in medicine and agriculture, for example as antidiabetic drugs widely used in the management of ...
*
Sulfonylurea
Sulfonylureas (UK: sulphonylurea) are a class of organic compounds used in medicine and agriculture, for example as antidiabetic drugs widely used in the management of diabetes mellitus type 2. They act by increasing insulin release from the beta ...
s (continued)
**
Tolazamide
Tolazamide is an Wiktionary:oral, oral blood glucose lowering medication, drug used for people with Type 2 diabetes. It is part of the sulfonylurea (medicine), sulfonylurea family (ATC A10BB).
Synthesis
para-toluenesulfonamide, ''para''-Toluene ...
**
Tolbutamide
Tolbutamide is a first-generation potassium channel blocker, sulfonylurea oral hypoglycemic medication. This drug may be used in the management of type 2 diabetes if diet alone is not effective. Tolbutamide stimulates the secretion of insulin by ...
**
Glibornuride
Glibornuride (INN) is an anti-diabetic drug from the group of sulfonylureas. It is manufactured by MEDA Pharma and sold in Switzerland under the brand name Glutril.
Synthesis
Gliburnide is an endo-endo derivative made from camphor-3-carboxami ...
**
Glisoxepide
Glisoxepide (INN) is an orally available anti-diabetic drug from the group of sulfonylurea
Sulfonylureas (UK: sulphonylurea) are a class of organic compounds used in medicine and agriculture, for example as antidiabetic drugs widely used in th ...
**
Glyclopyramide
Glyclopyramide ( INN, marketed under the tradename Deamelin-S) is a sulfonylurea drug used in the treatment of diabetes. It has been marketed in Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East ...
**
Gliclazide
Gliclazide, sold under the brand name Diamicron among others, is a sulfonylurea type of anti-diabetic medication, used to treat type 2 diabetes. It is used when dietary changes, exercise, and weight loss are not enough. It is taken by mouth.
...
**
Glibenclamide (glyburide)
**
Glipizide
Glipizide, sold under the brand name Glucotrol among others, is an anti-diabetic medication of the sulfonylurea class used to treat type 2 diabetes. It is used together with a diabetic diet and exercise. It is not indicated for use by itself in ...
**
Glimepiride
Glimepiride, is an anti-diabetic medication used to treat type 2 diabetes. It is less preferred than metformin. Use is recommended together with diet and exercise. It is taken by mouth. Glimepiride takes up to three hours for maximum effect and l ...
**
Glicaramide
Tandem pore domain channel blockers
Examples of
tandem pore domain channel blockers include:
*
Bupivacaine
Bupivacaine, marketed under the brand name Marcaine among others, is a medication used to decrease feeling in a specific area. In nerve blocks, it is injected around a nerve that supplies the area, or into the spinal canal's epidural space. It ...
*
Quinidine
Quinidine is a class I antiarrhythmic agent, class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of Antimalarial medication, antimalarial agent quinine, originally derived from the bark of the cinchona tre ...
*
Fluoxetine
Fluoxetine, sold under the brand names Prozac and Sarafem, among others, is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It is used for the treatment of major depressive disorder, obsessive–compulsive disorde ...
*
Seproxetine
Seproxetine, also known as (''S'')-norfluoxetine, is a selective serotonin reuptake inhibitor (SSRI). It is the ''S'' enantiomer of norfluoxetine, the main active metabolite of the widely used antidepressant fluoxetine; but little is known ...
(Norfluoxetine)
[
* 12-''O''-tetradecanoylphorbol-13-acetate (TPA) (phorbol 12-myristate 13-acetate).
]
Voltage-gated channel blockers
Examples of voltage-gated
Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel. The membrane potential alters the conformation of the channel proteins ...
channel blockers include:
*Some types of dendrotoxin
Dendrotoxins are a class of presynaptic neurotoxins produced by mamba snakes ('' Dendroaspis'') that block particular subtypes of voltage-gated potassium channels in neurons, thereby enhancing the release of acetylcholine at neuromuscular junctio ...
s
* 3,4-Diaminopyridine (amifampridine)
* 4-Aminopyridine (fampridine/dalfampridine)
* Adekalant
*Almokalant
Almokalant is a drug used to treat arrhythmia. It is a potassium channel blocker. It has been found to have teratogenic
Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-di ...
*Amiodarone
Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrilla ...
[Amiodarone also blocks CACNA2D2-containing voltage gated calcium channels]
* Azimilide
*Bretylium
Bretylium (also bretylium tosylate) is an antiarrhythmic agent. It blocks the release of noradrenaline from nerve terminals. In effect, it decreases output from the peripheral sympathetic nervous system. It also acts by blocking K+ channels and is ...
* Bunaftine
*Charybdotoxin
Charybdotoxin (CTX) is a 37 amino acid neurotoxin from the venom of the scorpion '' Leiurus quinquestriatus hebraeus'' (''deathstalker'') that blocks calcium-activated potassium channels. This blockade causes hyperexcitability of the nervous syst ...
* Clamikalant
*Conotoxin
A conotoxin is one of a group of neurotoxic peptides isolated from the venom of the marine cone snail, genus ''Conus''.
Conotoxins, which are peptides consisting of 10 to 30 amino acid residues, typically have one or more disulfide bonds. Cono ...
s, such as κ-conotoxin,
* Dalazatide
*Dofetilide
Dofetilide is a class III antiarrhythmic agent. It is marketed under the trade name Tikosyn by Pfizer, and is available in the United States in capsules containing 125, 250, and 500 µg of dofetilide. It is not available in Europe or Australia. I ...
[works by selectively blocking the rapid component of the ]delayed rectifier outward potassium current
Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized c ...
(IKr)
*Dronedarone
Dronedarone, sold under the brand name Multaq, is a medication by Sanofi-Aventis, mainly for the indication of cardiac arrhythmias. It was approved by the FDA on July 2, 2009. It was recommended as an alternative to amiodarone for the treatment ...
,[Guillemare E, Marion A, Nisato D, Gautier P, “Inhibitory effects of dronedarone on muscarinic K+ current in guinea pig atrial cells,” in Journal of Cardiovascular Pharmacology, 2000 7]
*E-4031
E-4031 is an experimental class III antiarrhythmic drug that blocks potassium channels of the hERG-type.
Chemistry
E-4031 is a synthetized toxin that is a methanesulfonanilide class III antiarrhythmic drug.
Target
E-4031 acts on a specif ...
[blocks ]potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of cel ...
s of the hERG-type
* Guangxitoxin
Guangxitoxin, also known as GxTX, is a peptide toxin found in the venom of the tarantula '' Plesiophrictus guangxiensis''. It primarily inhibits outward voltage-gated Kv2.1 potassium channel currents, which are prominently expressed in pancreati ...
[Primarily inhibits outward ]voltage-gated
Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel. The membrane potential alters the conformation of the channel proteins ...
Kv2.1 potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of cel ...
currents
Currents, Current or The Current may refer to:
Science and technology
* Current (fluid), the flow of a liquid or a gas
** Air current, a flow of air
** Ocean current, a current in the ocean
*** Rip current, a kind of water current
** Current (stre ...
.
*Hanatoxin
Hanatoxin is a toxin found in the venom of the '' Grammostola spatulata'' tarantula. The toxin is mostly known for inhibiting the activation of voltage-gated potassium channels, most specifically Kv4.2 and Kv2.1, by raising its activation thresh ...
* HgeTx1
* HsTx1[ a very potent inhibitor of the rat ]Kv1.3
Potassium voltage-gated channel, shaker-related subfamily, member 3, also known as KCNA3 or Kv1.3, is a protein that in humans is encoded by the ''KCNA3'' gene.
Potassium channels represent the most complex class of voltage-gated ion channels fro ...
voltage-gated potassium channel
Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized ce ...
*Ibutilide
Ibutilide is a Class III antiarrhythmic agent that is indicated for acute cardioconversion of atrial fibrillation and atrial flutter of a recent onset to sinus rhythm. It exerts its antiarrhythmic effect by induction of slow inward sodium current ...
,
* Inakalant
*Kaliotoxin
{, style="float: right; clear: right; margin: 0 0 0.5em 1em; background: #ffffff;" class="toccolours" border="0" cellpadding="1" align="right" width="280"
!The amino acid sequence of Kaliotoxin
, -
, bgcolor="#eeeeee" , N - Gly - Val - Glu - Ile ...
* Linopirdine
* Lolitrem B
* Maurotoxin
* Nifekalant
* Notoxin
*Paxilline
Paxilline is a toxic, tremorgenic diterpene indole polycyclic alkaloid molecule produced by ''Penicillium paxilli ''which was first characterized in 1975. Paxilline is one of a class of tremorigenic mycotoxins, is a potassium channel blocker, ...
* Pinokalant
*Quinidine
Quinidine is a class I antiarrhythmic agent, class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of Antimalarial medication, antimalarial agent quinine, originally derived from the bark of the cinchona tre ...
* ShK-186
*Sotalol
Sotalol, sold under the brand name Betapace among others, is a medication used to treat and prevent abnormal heart rhythms. It is only recommended in those with significant abnormal heart rhythms due to potentially serious side effects. Evidence ...
*Tedisamil
Tedisamil (3,7-dicyclopropylmethyl-9,9-tetramethylene-3,7-diazabicyclo-3,3,1-nonane) is an experimental class III antiarrhythmic agent currently being investigated for the treatment of atrial fibrillation. Tedisamil blocks multiple types of pota ...
* Terikalant
*Tetraethylammonium
Tetraethylammonium (TEA), () or (Et4N+) is a quaternary ammonium cation consisting of four ethyl groups attached to a central nitrogen atom, and is positively charged. It is a counterion used in the research laboratory to prepare lipophilic salts ...
[B. Hille (1967). "The selective inhibition of delayed potassium currents in nerve by tetraethylammonium ions." ''J. Gen. Physiol.'' 50 1287-1302.][C. M. Armstrong (1971). "Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons." ''J. Gen. Physiol.'' 58 413-437.]
* Verapamil
Verapamil, sold under various trade names, is a calcium channel blocker medication used for the treatment of high blood pressure, angina (chest pain from not enough blood flow to the heart), and supraventricular tachycardia. It may also be used ...
,
*Vernakalant
Vernakalant ( INN; EU trade name Brinavess; proposed US trade name Kynapid) is a pharmaceutical drug for the acute conversion of atrial fibrillation, a kind of irregular heartbeat, in form of an intravenous infusion. It has been approved for use ...
hERG
hERG (the human '' Ether-à-go-go''-Related Gene) is a gene () that codes for a protein known as Kv11.1, the alpha subunit of a potassium ion channel. This ion channel (sometimes simply denoted as 'hERG') is best known for its contribution to th ...
(KCNH2, Kv11.1)-specific
*Ajmaline
Ajmaline (also known by trade names Gilurytmal, Ritmos, and Aritmina) is an alkaloid that is classified as a 1-A antiarrhythmic agent. It is often used to induce arrhythmic contraction in patients suspected of having Brugada syndrome. Individuals ...
*Amiodarone
Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of cardiac dysrhythmias. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrilla ...
* AmmTX3
*Astemizole
Astemizole (marketed under the brand name Hismanal, developmental code R43512) was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It was withdrawn from the ma ...
*Azaspiracid
Azaspiracids (AZA) are a group of polycyclic ether marine algal toxins produced by the small dinoflagellate '' Azadinium spinosum'' that can accumulate in shellfish and thereby cause illness in humans.
Azaspiracid was first identified in the 199 ...
* AZD1305
* Azimilide
*Bedaquiline
Bedaquiline, sold under the brand name Sirturo, is a medication used to treat active tuberculosis. Specifically, it is used to treat multi-drug-resistant tuberculosis (MDR-TB) along with other medications for tuberculosis. It is used by mouth.
...
* BeKm-1
* BmTx3
*BRL-32872
BRL-32872 is an experimental drug candidate that provides a novel approach to the treatment of cardiac arrhythmia. Being a derivative of verapamil, it possesses the ability to inhibit Ca+2 membrane channels. Specific modifications in hydrogen bond ...
*Chlorpromazine
Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar dis ...
*Cisapride
Cisapride is a gastroprokinetic agent, a drug that increases motility in the upper gastrointestinal tract. It acts directly as a serotonin 5-HT4 receptor agonist and indirectly as a parasympathomimetic. Stimulation of the serotonin receptors incr ...
*Clarithromycin
Clarithromycin, sold under the brand name Biaxin among others, is an antibiotic used to treat various bacterial infections. This includes strep throat, pneumonia, skin infections, ''H. pylori'' infection, and Lyme disease, among others. Clarith ...
*Darifenacin
Darifenacin (trade name Enablex in United States and Canada, Emselex in the European Union) is a medication used to treat urinary incontinence due to an overactive bladder. It was discovered by scientists at the Pfizer research site in Sandwich, ...
*Dextropropoxyphene
Dextropropoxyphene is an analgesic in the opioid category, patented in 1955 and manufactured by Eli Lilly and Company. It is an optical isomer of levopropoxyphene. It is intended to treat mild pain and also has antitussive (cough suppressant) a ...
* Diallyl trisulfide
*Domperidone
Domperidone, sold under the brand name Motilium among others, is a dopamine antagonist medication which is used to treat nausea and vomiting and certain gastrointestinal problems like gastroparesis (delayed gastric emptying). It raises the le ...
*E-4031
E-4031 is an experimental class III antiarrhythmic drug that blocks potassium channels of the hERG-type.
Chemistry
E-4031 is a synthetized toxin that is a methanesulfonanilide class III antiarrhythmic drug.
Target
E-4031 acts on a specif ...
* Ergtoxins
*Erythromycin
Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used duri ...
* Gigactonine
*Haloperidol
Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychosi ...
*Ketoconazole
Ketoconazole, sold under the brand name Nizoral among others, is an antiandrogen and antifungal medication used to treat a number of fungal infections. Applied to the skin it is used for fungal skin infections such as tinea, cutaneous candid ...
* Norpropoxyphene
*Orphenadrine
Orphenadrine (sold under many brand names) is an anticholinergic drug of the ethanolamine antihistamine class; it is closely related to diphenhydramine. It is a muscle relaxant that is used to treat muscle pain and to help with motor control in Pa ...
*Pimozide
Pimozide (sold under the brand name Orap) is an antipsychotic drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weight basis i ...
* PNU-282,987
*Promethazine
Promethazine is a first-generation antihistamine, antipsychotic, sedative, and antiemetic used to treat allergies, insomnia, and nausea. It may also help with some symptoms associated with the common cold and may also be used for sedating people ...
*Quinidine
Quinidine is a class I antiarrhythmic agent, class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of Antimalarial medication, antimalarial agent quinine, originally derived from the bark of the cinchona tre ...
*Ranolazine
Ranolazine, sold under the brand name Ranexa among others, is a medication used to treat heart related chest pain. Typically it is used together with other medications when those are insufficient. Benefits appear smaller in women than men. It ...
* Roxithromycin
*Sertindole
Sertindole, sold under the brand name Serdolect among others, is an antipsychotic medication. Sertindole was developed by the Danish pharmaceutical company Lundbeck and marketed under license by Abbott Labs. Like other atypical antipsychotics, i ...
*Solifenacin
Solifenacin, sold as the brand name Vesicare among others, is a medicine used to treat overactive bladder and neurogenic detrusor overactivity (NDO). It may help with urinary incontinence, incontinence, urinary frequency, and urinary urgency.
...
*Tamulotoxin Tamulotoxin (or Tamulus toxin, Tamulustoxin, in short form: TmTx) is a venomous neurotoxin from the Indian Red Scorpion (''Hottentotta tamulus'', ''Mesobuthus tamulus'' or ''Buthus tamulus'').
Chemistry
Structure
The toxin has been classified ...
*Terodiline
Terodiline is a drug used in urology as an antispasmodic.
It relaxes the smooth muscle and used to reduce bladder tone in treatment of urinary frequency and incontinence. Muscle relaxation caused by terodiline, is probably due to its anticholine ...
*Terfenadine
Terfenadine is an antihistamine formerly used for the treatment of allergic conditions. It was brought to market by Hoechst Marion Roussel (now Sanofi-Aventis) and was marketed under various brand names, including Seldane in the United States, Tr ...
*Thioridazine
Thioridazine (Mellaril or Melleril) is a first generation antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis. The branded product was withdrawn worldwide ...
*Tolterodine
Tolterodine, sold under the brand name Detrol among others, is a medication used to treat frequent urination, urinary incontinence, or urinary urgency. Effects are seen within an hour. It is taken by mouth.
Common side effects include heada ...
*Vanoxerine
Vanoxerine is a piperazine derivative which is a potent and selective dopamine reuptake inhibitor (DRI). Vanoxerine binds to the target site on the dopamine transporter (DAT) ~ 50 times more strongly than cocaine, but simultaneously inhibits the ...
*Vernakalant
Vernakalant ( INN; EU trade name Brinavess; proposed US trade name Kynapid) is a pharmaceutical drug for the acute conversion of atrial fibrillation, a kind of irregular heartbeat, in form of an intravenous infusion. It has been approved for use ...
KCNQ (Kv7)-specific
* Linopirdine
* XE-991
* Spooky toxin (SsTx)
See also
* Potassium channel
Potassium channels are the most widely distributed type of ion channel found in virtually all organisms. They form potassium-selective pores that span cell membranes. Potassium channels are found in most cell types and control a wide variety of cel ...
* Potassium channel opener
A potassium channel opener is a type of drug which facilitates ion transmission through potassium channels.
Examples
Some examples include:
*Diazoxide vasodilator used for hypertension, smooth muscle relaxing activity
*Minoxidil vasodilator us ...
Notes
References
{{Antiarrhythmic agents