Are there any potential Vitamin K side-effects?
Every intervention carries the risk of unwanted side-effects.
Evaluating the possible risk against the expected benefit is a critical part of giving informed consent.
What are the potential side-effects of Konakion?
Potential side-effects of Konakion listed in the Patient Information Leaflet (PIL) are:
‘Allergic reactions
The signs may include:
- Swelling of your baby’s or child’s throat, face, lips and mouth. This may make it difficult for them to breathe or swallow.
- Sudden swelling of your baby’s or child’s hands, feet and ankles.
A reaction where the injection was given
- Rarely this may be severe. Signs include redness, swelling, pain and it may cause a scar.’
The PIL doesn’t give any statistics about the likelihood of a side-effect occurring.
‘Please tell your doctor, nurse or midwife if your child is taking or has recently taken any other medicines. This includes medicines that you buy without a prescription and herbal medicines.
This is because Konakion MM Paediatric can affect the way some medicines work.’
Informing Consent’s pharmacological adviser notes:
‘The active compound, phytomenadione, restores hepatic clotting factor activation. Its clinical benefit—reduction of rare but potentially severe bleeding events—is clear. However, parenteral administration has been associated with rare anaphylactoid reactions, including shock and cardiorespiratory compromise.
These events are infrequent but well described [see below], and notably may relate less to Vitamin K itself than to formulation components.’
Further reading:
What are the potential side-effects of Neokay?
The Patient Information Leaflet states that ‘There are no known side effects from taking Neokay.’
Adverse reaction reports
The Medicines & Healthcare products Regulatory Agency (MHRA) in the UK collects Yellow Card Reports, to record safety concerns about healthcare products.
It has a section about Vitamin K substances. It breaks down the reactions reported into age groups, and the lowest age group is 0-9 years. For most of the reports, the age is unknown. So we can’t see how many of these reports relate to newborns.
It also says that: ‘The information reported should not be interpreted as a list of possible side effects, nor should these data to be used to estimate the frequency of side effects or to compare the safety profile of different drugs.’
We know that many safety issues don’t get reported to the Yellow Card scheme. ‘It is estimated that only 10% of serious reactions and between 2 and 4% of non-serious reactions are reported.’
At the time of writing, 11,557 adverse events have been reported on the World Health Organization’s public information website, VigiAccess, for the active ingredient in Konakion Vitamin K injections, phytomenadione.
Concerns about a possible connection between newborn Vitamin K injection and childhood cancers were raised in a large UK study published in 1990 and confirmed in a subsequent study by the same team. Possible mechanisms for an increased cancer risk were discussed. But subsequent studies from the US, the UK, Germany and Sweden all failed to show any link.
A retired paediatrician remembers: ‘This debate continued for several years and the case was well argued for carrying out a proper randomised trial. Unfortunately, no-one took this up, so the uncertainty remains.’
Health Freedom Ireland provide detailed information about risks versus benefits in their vaccine booklet, and on their website. They also say that:
‘Assessing the risk of Vitamin K Deficiency Bleeding (VKDB) in newborns who don’t receive Vitamin K is difficult because supplementation has been standard practice before effective measurement methods were developed.’
Gaps in our knowledge
One of our medical advisers says:
‘Universal neonatal Vitamin K was introduced in the 1960s and there have never been any large-scale randomised trials. Studies were able to show that Vitamin K deficiency bleeding was reduced but there were no long-term studies looking at overall outcomes such as all-cause mortality.’