6. Drugs acting via ion channels

Cells are negatively polarized on the inside and positively polarized on the outside, resulting in a difference in electrical potential. Communication between the cell and its environment takes place via a variation in transmembrane potential resulting from a difference in ionic concentrations on either side of the cell membrane. Many drugs act through ion channels, opening or closing them to allow or prevent the passage of the corresponding ions. The result is an activating or inhibitory effect. Different types of ion channels are known, and many drugs exert their activity through them:

• Sodium channels: anti-arrhythmics, anti-malarials, anti-epileptics, local anaesthetics;

• calcium channels: different groups of drugs act on these channels: antihypertensives and anti-arrhythmics, inhibiting calcium channels;...