MASSACHUSETTS GENERAL HOSPITAL
Department of Pharmacy
Department of Nursing
Critical Care

Generic Name:

Phytonadione, Vitamin K

Trade Name:

AquaMephyton®

Action:

Promotes hepatic synthesis of coagulation factors II, VII, IX and X

Indications:

Prevention and treatment of hypoprothrombinemia caused by coumarin derivative-induced or drug-induced vitamin K deficiency

Hypoprothrombinemia secondary to factors limiting absorption or synthesis of vitamin K

Administration Guidelines:

Usual Dosage Range and Route:

Management of elevations in INR secondary to warfarin

The response to vitamin K 1 administered subcutaneously (SC) is less predictable compared to oral vitamin K 1 and is sometimes delayed.

Oral administration has the advantages of safety and convenience over parenteral routes and should be preferred when indicated.

INR

Action

Above therapeutic range to <5 and no significant bleeding and rapid reversal not indicated

Lower or hold the next warfarin dose and monitor frequently; when INR approaches desired range, may resume dosing with a lower dose if INR was significantly above therapeutic range.

=5 and <9 and no significant bleeding or <5 and rapid reversal indicated

Omit the next 1 or 2 warfarin doses; monitor INR and resume with a lower dose when the INR approaches the desired range.

Alternatively, if there are other risk factors for bleeding, omit the next warfarin dose and give vitamin K 1 orally =5 mg; resume with a lower dose when the INR approaches the desired range.

If rapid reversal is required hold warfarin then give vitamin K 1 orally 2-4 mg or 0.5-1mg IV or 1-2.5mg SC. Expect a response within 24 hours; another dose may be given if needed.

=9 and no significant bleeding

Hold warfarin, give vitamin K 1 orally 5-10 mg or 2.5mg IV or 5mg SC. Expect the INR to be reduced within 24-48 hours; monitor INR and administer additional vitamin K if necessary.

Any INR elevation and significant bleeding

Hold warfarin, give phytonadione 10 mg by slow I.V. infusion, and supplement with fresh plasma transfusion or prothrombin complex concentrate (Factor X complex); recombinant factor VIIa is an alternative to prothrombin complex concentrate. Vitamin K 1 injection can be repeated every 12 hours.

Intravenous doses of vitamin K should be administered over 20 minutes

Maximum infusion rate is 1mg/min

Standard Concentration:

Each dose mixed in 100 ml of 0.9% saline or D5W

Micro-Infusion Administration: Each dose mixed in 10 ml in a 60ml syringe “For ICU Only”

Special Considerations:

Severe reactions including: hypersensitivity, anaphylaxis, shock, cardiac arrest and/or respiratory arrest have occurred during or immediately after IV administration (even with proper dilution and rate of administration). Allergic reactions have also occurred with IM and subcutaneous injections.

Intravenous phytonadione should be restricted to those situations where the subcutaneous and oral routes are not feasible and the risk is justified.

Subcutaneous administration is recommended for patients with obstructive jaundice and/or biliary fistulas since the presence of bile salts is necessary for the absorption of phytonadione from the GI tract.

Monitor: PT, INR

Precautions and Side Effects:

Contraindicated in patients with hypersensitivity to phytonadione

Anaphylaxis

Hypotension, cardiac arrest

Dyspnea, respiratory arrest

Skin lesions (primarily with IM administration), flushing, cyanosis

Anaphylaxis

Anemia, thrombocytopenia

 

Mesac approved 6/19/07