Sodium and drugs
Sodium or Natrium, explaining the symbol Na, is an element largely widespread in nature and essential to life. Many drugs can modify its metabolism or its effects, generally by modifying its transmembrane passage.
Sodium is the principal cation of the extracellular liquids. The total amount of sodium in the body of an adult of 70kg is about 100g.
The atomic mass of sodium is 23, its covalent radius 1.54 A° and its ion radius 0.95 A°, close to that of Ca2+ which is 0.99 A° but which is doubly charged.
Because sodium can enter into cells across channels in a relatively specific way, it plays a determining part in the cellular depolarization which is at the origin of excitability and of conduction.