PHYTONADIONE- phytonadione injection, emulsion
General Injectables & Vaccines, Inc.
Severe reactions, including fatalities, have occurred during and immediately after INTRAVENOUS injection of phytonadione, even when precautions have been taken to dilute the phytonadione and to avoid rapid infusion. Severe reactions, including fatalities, have also been reported following INTRAMUSCULAR administration. Typically these severe reactions have resembled hypersensitivity or anaphylaxis, including shock and cardiac and/or respiratory arrest. Some patients have exhibited these severe reactions on receiving phytonadione for the first time.
Therefore the INTRAVENOUS and INTRAMUSCULAR routes should be restricted to those situations where the subcutaneous route is not feasible and the serious risk involved is considered justified.
Phytonadione is a vitamin, which is a clear, yellow to amber, viscous, odorless or nearly odorless liquid.
It is insoluble in water, soluble in chloroform and slightly soluble in ethanol. It has a molecular weight of 450.70. Phytonadione is 2-methyl-3-phytyl-1, 4-naphthoquinone. Its empirical formula is C31 H46 O2 and its structural formula is:
Phytonadione injectable emulsion, USP is a yellow, sterile, nonpyrogenic aqueous dispersion available for injection by the intravenous, intramuscular and subcutaneous routes.
Each milliliter contains phytonadione 10 mg, polyoxyethylated fatty acid derivative 70 mg, dextrose, hydrous 37.5 mg in water for injection; benzyl alcohol 9 mg added as preservative. May contain hydrochloric acid for pH adjustment. pH is 6.3 (5.0 to 7.0). Phytonadione is oxygen sensitive.
Phytonadione injectable emulsion, aqueous dispersion of phytonadione for parenteral injection, possesses 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 post-translational carboxylation of multiple, specific, peptide-bound glutamic acid residues in inactive hepatic precursors of factors II, VII, IX, and X. The resulting gamma-carboxy-glutamic acid residues convert the precursors into active coagulation factors that are subsequently secreted by liver cells into the blood.
Phytonadione is readily absorbed following intramuscular administration. 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 phytonadione. 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 pharamacological action of Vitamin K is related to its normal physiological function, that is, to promote the hepatic biosynthesis of Vitamin K dependent clotting factors.
The action of the aqueous dispersion, when administered intravenously, is generally detectable within an hour or two and hemorrhage is usually controlled within 3 to 6 hours. A normal prothrombin level may often be obtained in 12 to 14 hours.
In the prophylaxis and treatment of hemorrhagic disease of the newborn, phytonadione has demonstrated a greater margin of safety than that of the water-soluble Vitamin K analogues.
Phytonadione injectable emulsion, USP is 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 injectable emulsion is indicated in
anticoagulant-induced prothrombin deficiency caused by coumarin or indanedione derivatives;
prophylaxis and therapy of hemorrhagic disease of the newborn;
hypoprothrombinemia due to antibacterial therapy;
hypoprothrombinemia secondary to factors limiting absorption or synthesis of Vitamin K, e.g., obstructive jaundice, biliary fistula, sprue, ulcerative colitis, celiac disease, intestinal resection, cystic fibrosis of the pancreas, and regional enteritis;
other drug-induced hypoprothrombinemia where it is definitely shown that the result is due to interference with phytonadione injectable emulsion metabolism, e.g., salicylates.
Hypersensitivity to any component of this medication.
Benzyl alcohol as a preservative in Bacteriostatic Sodium Chloride Injection has been associated with toxicity in newborns. Data are unavailable on the toxicity of other preservatives in this age group.
There is no evidence to suggest that the small amount of benzyl alcohol contained in phytonadione injectable emulsion, USP, when used as recommended, is associated with toxicity.
An immediate coagulant effect should not be expected after administration of phytonadione. It takes a minimum of 1 to 2 hours for measurable improvement in the prothrombin time. Whole blood or component therapy may also be necessary if bleeding is severe.
Phytonadione will not counteract the anticoagulant action of heparin.
When Phytonadione is used to correct excessive anticoagulant-induced hypoprothrombinemia, anticoagulant therapy still being indicated, the patient is again faced with the clotting hazards existing prior to starting the anticoagulant therapy. Phytonadione is not a clotting agent, but overzealous therapy with phytonadione injectable emulsion may restore conditions which originally permitted thromboembolic phenomena.
Dosage should be kept as low as possible, and prothrombin time should be checked regularly as clinical conditions indicate.Repeated large doses of Vitamin K are not warranted in liver disease if the response to initial use of the vitamin is unsatisfactory. Failure to respond to Vitamin K may indicate that the condition being treated is inherently unresponsive to Vitamin K. Benzyl alcohol has been reported to be associated with a fatal “Gasping Syndrome” in premature infants. WARNING: This product contains aluminum that may be toxic.
Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired. Premature neonates are particularly at risk because their kidneys are immature, and they required large amounts of calcium and phosphate solutions, which contain aluminum. Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at greater than 4 to 5 mcg/kg/day accumulate aluminum at levels associated with central nervous system and bone toxicity. Tissue loading may occur at even lower rates of administration.
Temporary resistance to prothrombin-depressing anticoagulants may result, especially when larger doses of phytonadione are used. If relatively large doses have been employed, it may be necessary when reinstituting anticoagulant therapy to use somewhat larger doses of the prothrombin-depressing anticoagulant, or to use one which acts on a different principle, such as heparin sodium.
Prothrombin time should be checked regularly as clinical conditions indicate.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Studies of carcinogenicity, mutagenesis or impairment of fertility have not been conducted with phytonadione injectable emulsion.
Pregnancy Category C:
Animal reproduction studies have not been conducted with phytonadione injectable emulsion
It is also not known whether phytonadione injectable emulsion can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Phytonadione injectable emulsion should be given to a pregnant woman only if clearly needed.
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when phytonadione injectable emulsion is administered to a nursing woman.
Hemolysis, jaundice, and hyperbilirubinemia in neonates, particularly those that are premature, may be related to the dose of phytonadione injectable emulsion. Therefore, the recommended dose should not be exceeded (see ADVERSE REACTIONS AND DOSAGE AND ADMINISTRATION).
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