indication

Used to treat vitamin C deficiency, scurvy, delayed wound and bone healing, urine acidification, and in general as an antioxidant. It has also been suggested to be an effective antiviral agent.

pharmacology

Ascorbic Acid (vitamin C) is a water-soluble vitamin indicated for the prevention and treatment of scurvy, as ascorbic acid deficiency results in scurvy. Collagenous structures are primarily affected, and lesions develop in bones and blood vessels. Administration of ascorbic acid completely reverses the symptoms of ascorbic acid deficiency.

mechanism of action

In humans, an exogenous source of ascorbic acid is required for collagen formation and tissue repair by acting as a cofactor in the posttranslational formation of 4-hydroxyproline in -Xaa-Pro-Gly- sequences in collagens and other proteins. Ascorbic acid is reversibly oxidized to dehydroascorbic acid in the body. These two forms of the vitamin are believed to be important in oxidation-reduction reactions. The vitamin is involved in tyrosine metabolism, conversion of folic acid to folinic acid, carbohydrate metabolism, synthesis of lipids and proteins, iron metabolism, resistance to infections, and cellular respiration.

biotransformation

Hepatic. Ascorbic acid is reversibly oxidised (by removal of the hydrogen from the enediol group of ascorbic acid) to dehydroascorbic acid. The two forms found in body fluids are physiologically active. Some ascorbic acid is metabolized to inactive compounds including ascorbic acid-2-sulfate and oxalic acid.

absorption

70% to 90%

half life

16 days (3.4 hours in people who have excess levels of vitamin C)

drug interactions

Deferoxamine: Vitamin C may increase the adverse effects of deferoxamine. Transient deterioration of left ventricular function has been observed during concomitant therapy. Use caution during concomitant therapy.

Indinavir: Vitamin C decreases indinavir levels