1.1 Treatment of Hypoprothrombinemia Due to Vitamin K Deficiency or Interference

• anticoagulant-induced hypoprothrombinemia caused by coumarin or indanedione derivatives;
• 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 vitamin K metabolism, e.g., salicylates.

1.2 Prophylaxis and Treatment of Vitamin K-Deficiency Bleeding in Neonates

2.1 Dosing Considerations

Monitor international normalized ratio (INR) regularly and as clinical conditions indicate. Use the lowest effective dose of phytonadione injectable emulsion.

The coagulant effects of phytonadione injectable emulsion are not immediate; improvement of INR may take 1-8 hours. Interim use of whole blood or component therapy may also be necessary if bleeding is severe.

Whenever possible, administer benzyl alcohol-free formulations in pediatric patients [see Warnings and Precautions (5.2), Use in Specific Populations (8.4)].

When phytonadione injectable emulsion 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 INR should be checked regularly as clinical conditions indicate.

2.2 Recommended Dosage for Coagulation Disorders from Vitamin K Deficiency or Interference

• Anticoagulant-Induced Hypoprothrombinemia: Phytonadione injectable emulsion 2.5 mg to 10 mg or more subcutaneously, intramuscularly, or intravenously. Up to 25 mg to 50 mg may be administered as a single dose.

• Hypoprothrombinemia Due to Other Causes (Non-Anticoagulation-Induced Hypoprothrombinemia): Phytonadione injectable emulsion 2.5 mg to 25 mg or more intravenously, intramuscularly, or subcutaneously. Up to 50 mg may be administered as a single dose.

2.3 Recommended Dosage for Prophylaxis and Treatment of Vitamin K Deficiency Bleeding in Neonates

The recommended dosage of phytonadione injectable emulsion is 0.5 mg to 1 mg within one hour of birth for a single dose.

Treatment of Vitamin K Deficiency Bleeding in Neonates

The recommended dosage of phytonadione injectable emulsion is 1 mg given either subcutaneously or intramuscularly. Consider higher doses if the mother has been receiving oral anticoagulants.

A failure to respond (shortening of the INR in 2 to 4 hours) may indicate another diagnosis or coagulation disorder.

2.4 Directions for Dilution

When diluted, start administration of phytonadione injectable emulsion immediately after dilution.

Discard unused portions of diluted solution as well as unused contents of the ampul.

Protect phytonadione injectable emulsion from light at all times.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

5.1 Hypersensitivity Reactions

5.2 Risk of Serious Adverse Reaction in Infants due to Benzyl Alcohol Preservative

When prescribing phytonadione injectable emulsion in infants, consider the combined daily metabolic load of benzyl alcohol from all sources including phytonadione injectable emulsion (contains 9 mg of benzyl alcohol per mL) and other drugs containing benzyl alcohol. The minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known [see Use in Specific Populations (8.1, 8.2 and 8.4)].

5.3 Cutaneous Reactions

6.1 Clinical Trials and Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of phytonadione injectable emulsion. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Cardiac Disorders: Tachycardia, hypotension.

General disorders and administration site conditions: Generalized flushing; pain, swelling, and tenderness at injection site.

Hepatobiliary Disorders: Hyperbilirubinemia

Immune System Disorders: Fatal hypersensitivity reactions, anaphylactic reactions.

Neurologic: Dysgeusia, dizziness.

Pulmonary: Dyspnea.

Skin and Subcutaneous Tissue Disorders: Erythema, pruritic plaques, scleroderma-like lesions, erythema perstans.

Vascular: Cyanosis.

8.1 Pregnancy

Phytonadione injectable emulsion contains benzyl alcohol, which has been associated with gasping syndrome in neonates. The preservative benzyl alcohol can cause serious adverse events and death when administered intravenously to neonates and infants. If phytonadione injectable emulsion is needed during pregnancy, consider using a benzyl alcohol-free formulation [see Warnings and Precautions (5.2), Use in Specific Populations (8.4)].

Published studies with the use of phytonadione during pregnancy have not reported a clear association with phytonadione and adverse developmental outcomes [see Data]. There are maternal and fetal risks associated with vitamin K deficiency during pregnancy [see Clinical Considerations]. Animal reproduction studies have not been conducted with phytonadione.

The estimated background risk for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Clinical Considerations

Disease-associated maternal and/or embryo/fetal risk

Pregnant women with vitamin K deficiency hypoprothrombinemia may be at an increased risk for bleeding diatheses during pregnancy and hemorrhagic events at delivery. Subclinical maternal vitamin K deficiency during pregnancy has been implicated in rare cases of fetal intracranial hemorrhage.

Data

Human Data

Phytonadione has been measured in cord blood of infants whose mothers were treated with phytonadione during pregnancy in concentrations lower than seen in maternal plasma. Administration of vitamin K1 to pregnant women shortly before delivery increased both maternal and cord blood concentrations. Published data do not report a clear association with phytonadione and adverse maternal or fetal outcomes when used during pregnancy. However, these studies cannot definitively establish the absence of any risk because of methodologic limitations including small sample size and lack of blinding.

Animal Data

In pregnant rats receiving vitamin K1 orally, fetal plasma and liver concentrations increased following administration, supporting placental transfer.

8.2 Lactation

Phytonadione injectable emulsion contains benzyl alcohol. If available, preservative-free phytonadione injectable emulsion is recommended when phytonadione injectable emulsion is needed during lactation [see Warnings and Precautions (5.2), Use in Specific Populations (8.4)].

Phytonadione is present in breastmilk. There are no data on the effects of phytonadione injectable emulsion on the breastfed child or on milk production. The developmental and health benefits of breastfeeding should be considered along with the clinical need for phytonadione injectable emulsion and any potential adverse effects on the breastfed child from phytonadione injectable emulsion or from the underlying maternal condition.

8.4 Pediatric Use

Serious adverse reactions including fatal reactions and the "gasping syndrome" occurred in premature neonates and infants in the intensive care unit who received drugs containing benzyl alcohol as a preservative. In these cases, benzyl alcohol dosages of 99 to 234 mg/kg/day produced high levels of benzyl alcohol and its metabolites in the blood and urine (blood levels of benzyl alcohol were 0.61 to 1.378 mmol/L). Additional adverse reactions included gradual neurological deterioration, seizures, intracranial hemorrhage, hematologic abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse. Preterm, low-birth weight infants may be more likely to develop these reactions because they may be less able to metabolize benzyl alcohol.

When prescribing phytonadione injectable emulsion in infants consider the combined daily metabolic load of benzyl alcohol from all sources including phytonadione injectable emulsion (phytonadione injectable emulsion contains 9 mg of benzyl alcohol per mL) and other drugs containing benzyl alcohol. The minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known [see Warnings and Precautions (5.2)].

Whenever possible, use preservative-free phytonadione formulations in neonates. The preservative benzyl alcohol has been associated with serious adverse events and death in pediatric patients. Premature and low-birth weight infants may be more likely to develop toxicity.

12.1 Mechanism of Action

In normal animals and humans, phytonadione is virtually devoid of activity. However, in animals and humans deficient in vitamin K, the pharmacological action of vitamin K is related to its normal physiological function, that is, to promote the hepatic biosynthesis of vitamin K dependent clotting factors.

12.2 Pharmacodynamics

12.3 Pharmacokinetics

Phytonadione is readily absorbed following intramuscular administration.

Distribution:

After absorption, phytonadione is initially concentrated in the liver, but the concentration declines rapidly. Very little vitamin K accumulates in tissues.

Elimination:

Little is known about the metabolic fate of vitamin K. Almost no free unmetabolized vitamin K appears in bile or urine.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility