Skip to Content

The originating document has been archived. We cannot confirm the completeness, accuracy and currency of the content.


( K 1 ; Phylloquinone ; Methylphytyl Naphthoquinone )

Pronunciation: fye-TOE-na-DYE-one
Class: Vitamin K, Blood modifier

Trade Names

- Tablets, oral 5 mg

- Tablets, oral 100 mcg
- Injection 2 mg/mL
- Injection 10 mg/mL


Promotes hepatic synthesis of active prothrombin (factor II), proconvertin (factor VII), plasma thromboplastin component (factor IX), and Stuart factor (factor X).



Phytonadione is adequately absorbed from the GI tract only if bile salts are present. Phytonadione is rapidly absorbed following IM administration.


Following absorption, phytonadione is concentrated in the liver and the concentration rapidly declines. Very little vitamin K accumulates in tissues.


Very little is known about the metabolic fate of vitamin K.


Almost no free unmetabolized vitamin K appears in the bile or urine.


6 to 10 h (oral) and 1 to 2 h (parenteral); controls hemorrhage in approximately 3 to 6 h.

Indications and Usage

Management of coagulation disorders due to faulty formation of factors II, VII, IX, and X when caused by vitamin K deficiency or interference with vitamin K activity.


Factors limiting absorption or synthesis of vitamin K (eg, biliary fistulas, obstructive jaundice, sprue, ulcerative colitis) provided bile salts are given concurrently.


Treatment of anticoagulant-induced prothrombin deficiency; treatment of hypoprothrombinemia secondary to salicylates or antibacterial therapy; dietary supplement.


Treatment of hypoprothrombinemia secondary to conditions limiting absorption or synthesis of vitamin K; prophylaxis and therapy of hemorrhagic disease of the newborn.


None well documented.

Dosage and Administration

Anticoagulant-Induced Prothrombin Deficiency

PO / Subcutaneous / IM / IV 2.5 to 25 mg (rarely up to 50 mg). The dose may be repeated in 12 to 48 h after oral administration or 6 to 8 h after parenteral administration if the PT has not been shortened satisfactorily.

Dietary Supplement

PO 100 mcg daily, or as directed.

Hypoprothrombinemia Due to Other Causes

PO / Subcutaneous / IM / IV 2.5 to 25 mg (rarely up to 50 mg). When possible, discontinue or reduce the dosage of drugs interfering with coagulation mechanics (eg, salicylates, antibiotics) as an alternative to administering phytonadione.

Hemorrhagic Disease (Prophylaxis)

IM Single dose of 0.5 to 1 mg within 1 h of birth.

Hemorrhagic Disease (Treatment)

Subcutaneous / IM 1 mg accompanied by laboratory evaluation.

General Advice

  • Give subcutaneously or IM when possible. For adults and older children, inject IM in upper outer quadrant of buttocks. In infants and young children, anterolateral aspect of thigh or deltoid region is preferred.
  • Avoid IV route unless risk outweighs benefit. If IV administration is unavoidable, inject very slowly, not exceeding 1 mg/min.
  • Avoid oral route when the clinical disorder would prevent proper absorption.
  • Bile salts must be given when endogenous supply of bile to GI tract is deficient.
  • The dose and route should be determined by severity of the condition and response obtained.
  • Benzyl alcohol has been associated with toxicity in newborns; therefore, dilutions for newborns should be preservative free.


Store tablets between 59° and 86°F. Always protect from light. Store injection between 68° and 77°F. Protect from light until time to use.

Drug Interactions

Oral anticoagulants

Effects are antagonized by vitamin K, particularly in patients with advanced liver disease.

Laboratory Test Interactions

Paradoxical prolongation of PT after max doses of vitamin K.

Adverse Reactions


Cyanosis, hypotension, rapid and weak pulse.




Profuse sweating, transient flushing.


Peculiar taste sensations with parenteral administration.


Hyperbilirubinemia in newborns following parenteral administration.


Severe hypersensitivity reactions, including anaphylactoid reactions and death following parenteral administration.


Erythematous, indurated pruritic plaques that rarely may progress to scleroderma-like lesions; pain, swelling, and tenderness at injection site.






Severe reactions, including death, have occurred during and immediately after IV injection. Severe reactions have resembled hypersensitivity or anaphylaxis, including shock and cardiac and/or respiratory arrest. Events have occurred even when appropriate dilution was used to avoid rapid infusion. Some patients have exhibited symptoms on first administration of the drug. Thus, restrict IV and IM use for situations where other routes are not feasible and benefit/risk ratio is assessed.


Prothrombin time should be checked regularly as clinical conditions indicate.


Category C .




Oral: Safety and efficacy not established.


Use with caution, usually starting at the low end of the dosage range, because of the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant diseases or other drug therapy.


Rash, urticaria, or anaphylactoid reactions may occur.

Renal Function

Patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at more than 4 to 5 mcg/kg/day accumulate aluminum at levels associated with CNS and bone toxicity.

Hepatic Function

Giving vitamin K to correct hypoprothrombinemia associated with severe hepatitis or cirrhosis may further depress prothrombin concentration.


Patients may be refractory to oral anticoagulants, particularly large doses.


Giving vitamin K has no immediate coagulant effect. Management of bleeding involves standard measures (eg, transfusions).


Anticoagulant effect will not be counteracted by phytonadione.



No data available.

Patient Information

  • Explain that patient may experience temporary “flushing sensations” and “peculiar” sensations of taste. Rarely, dizziness, rapid weak pulse, profuse sweating, or difficulty breathing may occur. Another rare occurrence is pain, swelling, or tenderness at injection site.
  • Remind patients on anticoagulant and phytonadione therapy of importance of regular lab work to check PT. Anticoagulant effects are antagonized by vitamin K; therefore, temporary resistance to oral anticoagulants may result, especially when larger doses are used.
  • Instruct patient to report any symptoms of bleeding.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.