PHYTOMENADIONE
Vitamin K1, Konakion® MM Paediatric
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Reviewed by Brenda Hughes (Pharmacy), Dr Simon Rowley, Dr Carl Kuschel, and Helen Lamb (NSANP) |
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February 2007 |
Dose and Administration
Prophylaxis
- Term infant
- Intramuscluar injection 0.5-1mg IM at birth (preferred route)
- Oral administration
- 2mg oral soon after birth, then
- 2mg oral at 3-7 days, then
- 2mg oral at 6 weeks
| Note: |
- If the oral dose is vomited or regurgitated
within one hour, a repeat dose should be given.
- When this preparation is prescribed orally the
second and third doses may need to be administered after
the baby has been discharged from hospital.
- It is the responsibility of the LMC and
parents to ensure that subsequent doses are
administered.
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See the Vitamin K guideline
for information on the risks of
Vitamin K
Deficiency Bleeding (VKDB).
- Preterm infant <1.5kg
- 0.5mg IM at birth
Treatment of Vitamin K Deficiency Bleeding
1
- Intravenous 1 mg, repeated 8 hourly if necessary. Administer slowly.
Indications
- Prophylaxis of
Vitamin K Deficiency Bleeding (VKDB).
- Treatment of
VKDB or neonatal hypoprothrombinaemia.
Contraindications
- Lack of parental consent (see
Vitamin K guideline).
Precautions
- Delay IM administration in infants at risk of
HIV
and
haemophilia as per guidelines.
- Severe hepatic dysfunction.
- Bleeding disorders that are not vitamin K dependent.
- Parenteral administration may increase risk of kernicterus.2
Drug Interactions 3
Gentamicin: possible decrease in efficacy of IV vitamin K.
Clinical Pharmacology 2
Phytomenadione (synthetic Vitamin K1), part of the hepatic
carboxylase system, is essential for the formation of clotting factors II (prothrombin),
VII, IX, and X, plus the clotting inhibitor proteins C and S. Lack of
vitamin K results in an increased potential for haemorrhage. This can be
reversed by the administration of vitamin K.
In Konakion MM paediatric ampoules, the vitamin K is contained in a
physiological system of bile acid-lecithin micelles which result in a improved
local and systemic tolerance than previous injection solutions.
Given orally, the vitamin K is absorbed mainly from the middle of the small
intestine. Absorption is enhanced by the presence of bile and pancreatic
juice; absorption is impaired by short bowel syndrome, biliary atresia,
pancreatic insufficiency, and malabsorption syndromes. Systemic availability is
approximately 50%, with wide inter-patient variability.
Vitamin K is eliminated by metabolic glucuronidation and sulphation. The
half life is 1.5 to 3 hours (adults).
Possible Adverse Effects 2
- Anaphylactoid reaction.
- Local irritation possible, but is rare.
Special Considerations
- Konakion MM® Paediatric is licensed for oral and parenteral
administration.
- Intravenous administration should
be reserved for potentially fatal haemorrhage.
- Prothrombin synthesis takes up to
2 hours to occur following parenteral administration of vitamin K.
- Efficacy of treatment with vitamin
K is decreased with liver disease.