Vitamin K

Disambiguation: See ketamine for street name "vitamin K"

General

• Lasts up to 2 weeks, possibly making anticoagulation post-bleeding risk difficult
• IV form has small risk of anaphylaxis, but risks/benefits must be weighed in serious bleeding
• Type: Vitamin
• Dosage Forms: 100 mcg; 5mg; SC; IM; IV; PO
• Common Trade Names: Generic and Mephyton, K1-1000, Novaplus Vitamin K1

Adult Dosing

Vitamin K deficiency hypoprothrombinemia

• 2.5-25mg PO QD PRN
• Max: 25mg/dose

Anticoagulant-induced hypoprothrombinemia

• 10mg PO x1
• Max: 25mg/dose

Warfarin stabilization

• 100 mcg PO QD-bid

Pediatric Dosing

Neonatal deficiency (hemorrhagic disease of the newborn)

• 1mg SC for avoidance of anaphylaxis (IV), hematoma (IM). FFP for serious cases.

Vitamin K deficiency hypoprothrombinemia

• 2.5-5mg PO QD PRN

anticoagulant induced hypoprothrombinemia

• 0.5-5mg PO/SC/IM/IV x 1

Special Populations

• Pregnancy Rating: C
• Lactation risk: Safe
• Renal Dosing
  • Adult: not defined
  • Pediatric: not defined
• Hepatic Dosing
  • Adult: adjust dose amount
  • Pediatric: adjust dose amount

Contraindications

• Allergy to class/drug
• hereditary hypoprothrombinemia
• overanticoagulation due to heparins
• caution in neonates

Adverse Reactions

Serious

• anticoagulant resistance
• hypersensitivity reaction, severe or life-threatening (SC, IM, or IV use)
• anaphylaxis (SC, IM, or IV use)
• hyperbilirubinemia (neonates)
• hemolytic anemia (neonates)

Common

• taste changes (SC, IM, or IV use)
• flushing (SC, IM, or IV use)
• injection site hematoma
• injection site pain

Pharmacology

• Half-life: unknown
• Metabolism: liver, CYP450: unknown
• Excretion: urine, bile
• Mechanism of Action: Used by liver for synthesis of some coagulation factors (II,VII,IX,X,C,S). Timing in the synthesis of these factors impacts reversal of elevated INR (~4 hours: F-VII, ~24 hours: F-II).