Self-injection and anticoagulants

[Dexy123]

Giving serious thought to self-injecting as I’ve just started on 3 monthly injections with neuropathy symptoms getting worse again after big improvements on more frequent injections. I take 10 mg rivaroxaban daily to prevent blood clots from inherited thrombophilia. I was prescribed 9 loading doses over 1 month and 6 x 1 monthly injections, so I know that it’s OK to receive injections as frequently as this on anticoagulants. Just wondering if anyone has been in a similar situation?

[Foggyme Administrator]

Hi Dexy123

There are a few medical conditions where vitamin B12 should to be used with caution, and clotting disorders and other blood conditions are some of those conditions.

This is because Vitamin B12 can affect platelets (one of the bloods clotting mechanisms).B12 injections can also affect some blood test results - perhaps for 24-48 hours after an injections (especially pertinent if you have to have INF tested or blood tests to monitor medications), making it difficult to effectively monitor your condition. (Note that the potential changes are minor and not usually significant for those without underlying conditions that affect clotting (or those with a history of blood clots (embolism)...or those with stents in place).

Here's a link with a short mention that confirms impact on platelets (there will be more information out there if you search the Internet - apologies unable to search for more information right now).

drugs.com/pro/hydroxocobala...

Under these conditions it would be sensible to continue with B12 injections under medical supervision so that appropriate monitoring of your thrombophilia and medications can take place.

I hasten to say that it's not the case that B12 is unsafe, or that you shouldn't have any (of course, B12 deficiency must be treated). The ideal is to have injections frequently enough to keep symptoms at bay - but no more than is necessary to do just that: whilst simultaneously monitoring your thrombophilia / blood clotting. Any risk is potentially very very small, but with clotting issues - best to be appropriately monitored by a medical professional.

It's also worth adding that previously having had monthly B12 injections is no guarantee that it is safe to self-inject at that frequency on an ongoing basis, without medical supervision (because of the reasons outlined above).

I hope that your doctor will prescribe enough B12 to keep you symptom free and in good health...whilst also monitoring your blood clotting and medications.

Good luck

[Dexy123]

Many thanks Foggyme for taking the time to give such a detailed response. I had hoped that this might be a common issue but taking on board your thoughts and my own worries, I don’t plan to rush into anything and I’m at a fairly early stage of treatment so it remains to be seen as to whether the current treatment will be sufficient or whether my GP will let me have the 8 weekly injections as per NICE guidelines. I just wanted to consider my options fully to avoid further nerve damage. If the neuropathy symptoms get even worse then not taking the rivaroxaban may be an option as the suggested prescription was more so a precautionary measure based on my siblings recent PE rather than my own pill-induced DVT. Ironically it was the haematology consultants who omitted to mention to me that my b12 was very low several years ago! Thanks once again

[Foggyme Administrator in reply to Dexy123]

Hi Dexy123. Really pleased you found the information useful.

Just another quick comment...with your family history of PE and your DVT, it wouldn't be a good idea to stop the rivaroxaban without discussing it with your GP first.

Given that B12 action on platelets may result in a (albeit) small increase in clotting risk in those who are already susceptible, taking the rivaroxaban is more likely to reduce and mitigate any potential risk, rather than increase it. So stopping it won't be beneficial in terms of reducing the potential temporary increase of clotting risks (however small that risk may be) in those who may be susceptible due to underlying health conditions. (I hasten to note for anyone reading that this is not an issue for those who do not have an underlying blood disorder or issues with blood clotting).

If your neurogical symptoms get worse or do not lessen with more frequent B12 injections, it's worth asking for a referral to a neurologist. There are many causes of neurological symptoms so it would be usual practice to rule out the possibility of an underlying cause for the neurological symptoms, if these continue.

Quite shocking that the haematologist failed to point out and action your long-standing B12 deficiency. Shocking...but sadly not unusual.

Good luck x