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Phytonadione
Pronunciation
U.S. Brand Names
Generic Available
Synonyms
Pharmacological Index
Use
Pregnancy Risk Factor
Contraindications
Warnings/Precautions
Adverse Reactions
Drug Interactions
Stability
Mechanism of Action
Pharmacodynamics/Kinetics
Usual Dosage
Monitoring Parameters
Mental Health: Effects on Mental Status
Mental Health: Effects on Psychiatric Treatment
Dental Health: Local Anesthetic/Vasoconstrictor Precautions
Dental Health: Effects on Dental Treatment
Patient Information
Nursing Implications
Dosage Forms
Extemporaneous Preparations
References

Pronunciation
(fye toe na DYE one)

U.S. Brand Names
AquaMEPHYTON® Injection; Konakion® Injection; Mephyton® Oral

Generic Available

No


Synonyms
Methylphytyl Napthoquinone; Phylloquinone; Phytomenadione; Vitamin K1

Pharmacological Index

Vitamin, Fat Soluble


Use

Prevention and treatment of hypoprothrombinemia caused by drug-induced or anticoagulant-induced vitamin K deficiency, hemorrhagic disease of the newborn; phytonadione is more effective and is preferred to other vitamin K preparations in the presence of impending hemorrhage; oral absorption depends on the presence of bile salts


Pregnancy Risk Factor

C


Contraindications

Hypersensitivity to phytonadione or any component


Warnings/Precautions

Severe reactions resembling anaphylaxis or hypersensitivity have occurred rarely during or immediately after I.V. administration (even with proper dilution and rate of administration); restrict I.V. administration for emergency use only; ineffective in hereditary hypoprothrombinemia, hypoprothrombinemia caused by severe liver disease; severe hemolytic anemia has been reported rarely in neonates following large doses (10-20 mg) of phytonadione


Adverse Reactions

<1%: Transient flushing reaction, rarely hypotension, cyanosis, dizziness (rarely), pain, abnormal taste, GI upset (oral), hemolysis in neonates and in patients with G-6-PD deficiency, tenderness at injection site, dyspnea, diaphoresis, anaphylaxis, hypersensitivity reactions


Drug Interactions

Decreased effect: Warfarin sodium, dicumarol, anisindione effects antagonized by phytonadione; mineral oil may decrease GI absorption of vitamin K


Stability

Protect injection from light at all times; may be autoclaved


Mechanism of Action

Promotes liver synthesis of clotting factors (II, VII, IX, X); however, the exact mechanism as to this stimulation is unknown. Menadiol is a water soluble form of vitamin K; phytonadione has a more rapid and prolonged effect than menadione; menadiol sodium diphosphate (K4) is half as potent as menadione (K3).


Pharmacodynamics/Kinetics

Onset of increased coagulation factors: Oral: Within 6-12 hours; Parenteral: Within 1-2 hours; prothrombin may become normal after 12-14 hours

Absorption: Oral: Absorbed from the intestines in the presence of bile

Metabolism: In the liver rapidly

Elimination: In bile and urine


Usual Dosage

I.V. route should be restricted for emergency use only

Infants: 1-5 mcg/kg/day

Adults: 0.03 mcg/kg/day

Hemorrhagic disease of the newborn:

Prophylaxis: I.M.: 0.5-1 mg within 1 hour of birth

Treatment: I.M., S.C.: 1-2 mg/dose/day

Oral anticoagulant overdose:

Infants: I.M., S.C.: 1-2 mg/dose every 4-8 hours

Children and Adults: Oral, I.M., I.V., S.C.: 2.5-10 mg/dose; rarely up to 25-50 mg has been used; may repeat in 6-8 hours if given by I.M., I.V., S.C. route; may repeat 12-48 hours after oral route

Vitamin K deficiency: Due to drugs, malabsorption or decreased synthesis of vitamin K

Infants and Children:

Oral: 2.5-5 mg/24 hours

I.M., I.V.: 1-2 mg/dose as a single dose

Adults:

Oral: 5-25 mg/24 hours

I.M., I.V.: 10 mg


Monitoring Parameters

PT


Mental Health: Effects on Mental Status

May rarely cause dizziness


Mental Health: Effects on Psychiatric Treatment

None reported


Dental Health: Local Anesthetic/Vasoconstrictor Precautions

No information available to require special precautions


Dental Health: Effects on Dental Treatment

No effects or complications reported


Patient Information

Oral: Take only as directed; do not take more or more often than prescribed. Avoid excessive or increased intake of vitamin K containing food (eg, green leafy vegetables, dairy products, meats) unless recommended by prescriber. Avoid alcohol and any OTC or prescribed medications containing aspirin that are not approved by prescriber. Report bleeding gums; blood in urine, stool, or vomitus; unusual bruising of bleeding; or abdominal cramping. Pregnancy precautions: Inform prescriber if you are or intend to be pregnant.


Nursing Implications

I.V. administration: Dilute in normal saline, D5W or D5NS and infuse slowly; rate of infusion should not exceed 1 mg/minute. This route should be used only if administration by another route is not feasible for phytonadione; I.V. administration should not exceed 1 mg/minute; for I.V. infusion, dilute in PF (preservative free) D5W or normal saline.


Dosage Forms

Injection:

Aqueous colloidal: 2 mg/mL (0.5 mL); 10 mg/mL (1 mL, 2.5 mL, 5 mL)

Aqueous (I.M. only): 2 mg/mL (0.5 mL); 10 mg/mL (1 mL)

Tablet: 5 mg


Extemporaneous Preparations

A 1 mg/mL oral suspension was stable for only 3 days when refrigerated when compounded as follows:

Shake well before using and keep in refrigerator

Nahata MC and Hipple TF, Pediatric Drug Formulations, 3rd ed, Cincinnati, OH: Harvey Whitney Books Co, 1997.


References

Barash P, Kitahata LM, and Mandel S, "Acute Cardiovascular Collapse After Intravenous Phytonadione," Anesth Analg, 1976, 55(2):304-6.

Harrell CC and Kline SS, "Oral Vitamin K1: An Option to Reduce Warfarin's Activity," Ann Pharmacother, 1995, 29(12):1228-32.

Hopkins CS, "Adverse Reaction to a Cremophor-Containing Preparation of Intravenous Vitamin K," Intensive Therapy Clin Monit, 1988, 9:254-5.

Martinez-Abad M, Delgado F, Palop V, et al, "Vitamin K1 and Anaphylactic Shock," DICP, 1991, 25(7-8):871-2.

Michelson AD, Bovill E, Monagle P, et al, "Antithrombic Therapy in Children," Chest, 1998, 114(5 Suppl):748S-69S.

Shearer MJ, "Vitamin K," Lancet, 1995, 345(8944):229-34.


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