Sodium

Sodium

Sodium is the major cation in ECF. Sodium performs many func-tions:

·                 It maintains the osmotic pressure and concentration of ECF, acid-base balance, and water balance.

·                 It contributes to nerve conduction and neuromuscular function.

·                 It plays a role in glandular secretion.

Don’t sweat it

Sodium replacement is necessary in conditions that rapidly de-plete sodium, such as anorexia, excessive loss of GI fluids, and ex-cessive perspiration. Diuretics and tap water enemas can also de-plete sodium, particularly when fluids are replaced by plain water.

The salt flats

Sodium also can be lost in trauma or wound drainage, adrenal gland insufficiency, cirrhosis of the liver with ascites, syndrome of inappropriate antidiuretic hormone, and prolonged I.V. infusion of dextrose in water without other solutes.

Calling all chlorides

Sodium is typically replaced in the form of sodium chloride.

Pharmacokinetics

Oral and parenteral sodium chloride are quickly absorbed and distributed widely throughout the body.

Metabolism and excretion

Sodium chloride isn’t significantly metabolized. It’s elimi-nated primarily in urine but also in sweat, tears, and saliva.

Pharmacodynamics

Sodium chloride solution replaces deficiencies of the sodi-um and chloride ions in the blood plasma.

Pharmacotherapeutics

Sodium chloride is used for water and electrolyte replacement in patients with hyponatremia from electrolyte loss or severe sodium chloride depletion.

A welcome infusion

Severe symptomatic sodium deficiency may be treated by I.V. infu-sion of a solution containing sodium chloride.

Drug interactions

No significant drug interactions have been reported with sodium chloride. (See Adverse reactions to sodium.)