Vitamin K
Synonyms :
Phytomenadione, Phytonadine, Phytonadione, Vitamin K1
Mechanism :
Vitamin K compounds are fat soluble naphthoquinones. Vitamin K1 and vitamin K2 occur in a variety of natural materials and are synthesized by certain bacteria in the gastrointestinal tract; however, commercially prepared phytonadione is synthetically produced. Phytonadione possesses essentially the same type and degree of activity as naturally occurring vitamin K1.
Indication :
- Vitamin K deficiency prophylaxis
- Hemorrhagic disease of newborn
- Malabsorption syndrome
- Cystic fibrosis
- Biliary atresia
- Hepatic failure
- Antidote to warfarin
Contraindications :
Hypersensitivity to vitamin K.
Dosing :
RDA:
0-6 months: 2 mcg/day
6-12 months: 2.5 mcg/day
1-3 years: 30 mcg/day
4-8 years: 55 mcg/day
9-13 years: 60 mcg/day
14-18 years: 75 mcg/day
1 mg can be given IM to healthy neonates >36 weeks gestation, at birth or shortly after.
For deficiency of Vitamin K in infants and children:
2.5 to 5 mg orally once every 24 hours. Alternatively, 1 to 2 mg IV, IM or subcutaneously may be administered.
Deficiency in Adolescents:
2.5 to 25 mg orally once every 24 hours. Alternatively, 10 mg IV, IM or subcutaneously may be administered.
Adverse Effect :
Transient flushing sensations and peculiar sensations of taste have been observed following phytonadione injection as well as rare instances of dizziness, rapid and weak pulse, profuse sweating, brief hypotension, dyspnea, and cyanosis. Bronchospasm, shock, cardiac and/or respiratory arrest may also occur. Pain, swelling, and tenderness at the injection site may occur. Large doses of vitamin K or its analogues may further depress liver function in patients with severe hepatic disease and thereby further decrease the concentration of prothrombin.
Neonates: In infants (particularly premature babies), excessive doses of vitamin K analogs during the first few days of life may cause hyperbilirubinemia; this in turn may result in severe hemolytic anemia, hemoglobinuria, kernicterus, leading to brain damage or even death.
Interaction :
No significant interactions are known other than antagonism of coumarin anticoagulants.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Unlikely to be dialysed. Dose as in normal renal function |
| HD | Unlikely to be dialysed. Dose as in normal renal function |
| HDF/High flux | Dialysed. Dose as in normal renal function |
| CAV/VVHD | Unlikely to be dialysed. Dose as in normal renal function |
Hepatic Dose :
No dose adjustment recommended.