PHYTONADIONE tablet

Country: United States

Language: English

Source: NLM (National Library of Medicine)

Active ingredient:

PHYTONADIONE (UNII: A034SE7857) (PHYTONADIONE - UNII:A034SE7857)

Available from:

AvPAK

Administration route:

ORAL

Prescription type:

PRESCRIPTION DRUG

Therapeutic indications:

Phytonadione tablets are indicated in the following coagulation disorders which are due to faulty formation of factors II, VII, IX and X when caused by vitamin K deficiency or interference with vitamin K activity. Phytonadione tablets are indicated in: - anticoagulant-induced prothrombin deficiency caused by coumarin or indanedione derivatives; - hypoprothrombinemia secondary to antibacterial therapy; - hypoprothrombinemia secondary to administration of salicylates; - hypoprothrombinemia secondary to obstructive jaundice or biliary fistulas but only if bile salts are administered concurrently, since otherwise the oral vitamin K will not be absorbed. Hypersensitivity to any component of this medication.

Product summary:

Phytonadione tablets, 5 mg vitamin K 1 , are yellow, round, scored, compressed tablets, coded VRX 405 on one side and MEPHYTON on the other. They are supplied as follows: Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Always protect phytonadione tablets from light. Store in tightly closed original container and carton until contents have been used (see PRECAUTIONS, General ).

Authorization status:

New Drug Application Authorized Generic

Summary of Product characteristics

PHYTONADIONE- PHYTONADIONE TABLET
AVPAK
----------
PHYTONADIONE TABLETS
RX ONLY
DESCRIPTION
Phytonadione is a vitamin which is a clear, yellow to amber, viscous,
and nearly odorless
liquid. It is insoluble in water, soluble in chloroform and slightly
soluble in ethanol. It has a
molecular weight of 450.7.
Phytonadione is 2-methyl-3-phytyl-1, 4-naphthoquinone. Its empirical
formula is C
H
O
and its structural formula is:
Phytonadione tablets containing 5 mg of phytonadione are yellow,
compressed tablets,
scored on one side. Inactive ingredients are acacia, calcium
phosphate, colloidal silicon
dioxide, lactose, magnesium stearate, starch, and talc.
CLINICAL PHARMACOLOGY
Phytonadione tablets possess the same type and degree of activity as
does naturally-
occurring vitamin K, which is necessary for the production via the
liver of active
prothrombin (factor II), proconvertin (factor VII), plasma
thromboplastin component
(factor IX), and Stuart factor (factor X). The prothrombin test is
sensitive to the levels of
three of these four factors – II, VII, and X. Vitamin K is an
essential cofactor for a
microsomal enzyme that catalyzes the posttranslational carboxylation
of multiple,
specific, peptide-bound glutamic acid residues in inactive hepatic
precursors of factors
II, VII, IX, and X. The resulting gamma-carboxyglutamic acid residues
convert the
precursors into active coagulation factors that are subsequently
secreted by liver cells
into the blood.
Oral phytonadione is adequately absorbed from the gastrointestinal
tract only if bile salts
are present. After absorption, phytonadione is initially concentrated
in the liver, but the
concentration declines rapidly. Very little vitamin K accumulates in
tissues. Little is known
about the metabolic fate of vitamin K. Almost no free unmetabolized
vitamin K appears in
bile or urine.
In normal animals and humans, phytonadione is virtually devoid of
pharmacodynamic
activity. However, in animals and humans deficient in vitamin K, the
pharmacological
action of vitamin K is relate