Ion Channel Blockers

A channel blocker is a molecule, usually a cation, anion, or a specialized biological molecule such as a neurotoxin, that binds as an antagonist to ion channels and effectively prevents their normal function.

Such channel blockers can have a devastating effect, with the example of neurotoxins like tetrodotoxin that prevent action potentials on the membrane of the axon of a neuron by blocking the flux of ions, thus blocking the transfer of information.

On the other hand, due to their specificity, some of those channel blockers present definite therapeutic properties to treat for example neuro-degenerative diseases. By treating specific channels connected to a disease, the symptoms might be inhibited. Some progress has been made this way for treatments against Alzheimer's disease, but also multiple sclerosis and the treatment of pain.

The most prominent ion channel blockers target sodium, calcium, potassium and chloride ion channels.

• Calcium channel blockers have demonstrated a therapeutic effect notably against hypertension
• Potassium channel blockers extend the duration of the polarization of the action potential, and have shown therapeutic benefit against heart arrhythmia.
• Extracellular sodium channel blockers are usually toxins, while intracellular blockers have positive effects on arrhythmia, as well as anesthetic and anti-convulsion properties.
• Chloride channel blockers have not demonstrated therapeutic properties yet.