INDICES> INDICES: Vitamin K and upper GI bleeding (3)

["Janet McNeece" <Jmcneece@mail.rah.sa.gov.au>]

INDICES: Vitamin K and upper GI bleeding (3)

Dear Sir,
We have investigated your enquiry regarding the evidence for the use of
vitamin K to treat bleeding in patients with liver disease.  After a search
of Micromedex, Medline, Embase and IDIS this is our reply.

While it is accepted that vitamin K can be used for treating
coagulopathies in liver disease there appears to be no specific studies
supporting it.  It is well documented that vitamin K promotes the
formation of liver coagulation factors II, VII, IX and X and anticoagulant
proteins C and S by the liver.  In liver disease there is impaired synthesis
of these clotting factors, resulting in a prolonged prothrombin time.
However, this lack of production of clotting factors is more likely
associated with impaired hepatocytes (specifically an altered
endoplasmic reticulum, responsible for protein synthesis) than a
deficiency in vitamin K.  Therefore administering vitamin K to patients
with severe liver disease will only have a partial effect, if any, at
improving prolonged prothrombin time.

In situations where a patient is vitamin K deficient as well as having
impaired hepatocytes a better response to vitamin K may be observed.
This includes patients with biliary tract disease where the effect on bile
salts can lead to deficiency in vitamin K, and patients receiving broad
spectrum antibiotics which when coupled with poor dietary intake can
lead to coagulopathy even in less severe disease.

The standard dosing of vitamin K is 10-15 mg per day, not exceeding 3
doses.  Treating patients with vitamin K for too long without response
can lead to a paroxysmal increase in prothrombin time.  For this reason if
no response has been seen after 3 days of therapy the vitamin K should
be ceased.

Overall the rationale for using vitamin K in patients with liver disease is
to use whatever liver?s left that is capable of producing clotting factors
and improving prothrombin time to do so.


References:
Sallah,S, Bobzien; W, Bleeding Problems in Patients with Liver
    Disease, Postgraduate Medicine, 1999; 106: 187-195
Lucena,M et al; Multicenter hospital study on prescribing patterns
    for prophylaxis and treatment of complications of cirrhosis,
    European journal of clinical pharmacology, 2002; 58:435-440
Shearer,M; Vitamin K, The Lancet, 1995; 345:229-345
Kelly,D; Managing liver failure, Postgraduate medical journal, 2002;
    78: 660-667


>From Lauren Cortis Intern Pharmacist
Janet McNeece Senior Pharmacist
Medicines Information Centre
Royal Adelaide Hospital
South Australia

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