Blood
Medicines for Pernicious anaemia
A type of vitamin B12 deficiency caused by the body being unable to absorb B12, leading to anaemia and nerve symptoms — effectively treated with B12 injections.
Education and reference only. This explains which medicines are used and why, in plain language — it deliberately contains no doses and is not a substitute for advice from your doctor or pharmacist. Always discuss your own treatment with a qualified clinician, and check the BNF and the product labelling for prescribing detail.
Quick answer
What is Pernicious anaemia?
Pernicious anaemia is a condition in which the body cannot absorb enough vitamin B12 from food, leading to a B12 deficiency. It is an autoimmune condition: the immune system attacks the cells in the stomach that produce a substance (intrinsic factor) needed to absorb B12.
- How it is treated: Because the problem is with absorbing B12 rather than getting enough from food, treatment is usually with vitamin B12 given by injection, which bypasses the absorption problem.
- Self-care: Taking B12 injections as scheduled for life is the key, as the underlying absorption problem does not resolve.
- When to seek help: See a GP about persistent tiredness, breathlessness, a sore tongue, or tingling and numbness, so B12 levels can be checked.
What it is
Pernicious anaemia is a condition in which the body cannot absorb enough vitamin B12 from food, leading to a B12 deficiency. It is an autoimmune condition: the immune system attacks the cells in the stomach that produce a substance (intrinsic factor) needed to absorb B12. Because B12 is essential for making healthy red blood cells and keeping nerves healthy, deficiency causes a particular type of anaemia — with tiredness, breathlessness, pallor and a sore tongue — and can cause nerve-related symptoms such as tingling, numbness, balance problems and, if severe and prolonged, memory or mood changes. It is more common in older adults and can run in families or occur with other autoimmune conditions. It is diagnosed with blood tests, including for B12 and specific antibodies.
How it is treated
Because the problem is with absorbing B12 rather than getting enough from food, treatment is usually with vitamin B12 given by injection, which bypasses the absorption problem. This is typically started with a course of injections to replenish stores, followed by regular maintenance injections for life, as the absorption problem is ongoing. Symptoms usually improve, and treating it promptly helps prevent lasting nerve damage. Because it is autoimmune, people may be checked for related conditions such as thyroid problems. Monitoring ensures the treatment is working. Occasionally high-dose oral B12 is used in certain situations, but injections are the mainstay for pernicious anaemia.
For this condition, these medicines
Medicine classes used for Pernicious anaemia
Each links to a full, dose-free guide — what it is, how it works, who can and cannot use it, side effects, interactions and FAQs.
Beyond medication
Lifestyle and self-care
Taking B12 injections as scheduled for life is the key, as the underlying absorption problem does not resolve. Reporting new or worsening nerve symptoms, and attending monitoring, help ensure treatment is effective.
When to get help
When to see a doctor
See a GP about persistent tiredness, breathlessness, a sore tongue, or tingling and numbness, so B12 levels can be checked. Report new or worsening nerve symptoms promptly, as early treatment helps prevent lasting damage.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
Answers
Pernicious anaemia: frequently asked questions
Why does pernicious anaemia need injections rather than tablets?
Because the body cannot absorb B12 properly from the gut, injections are used to bypass the absorption problem. They are usually needed for life, as the underlying cause is ongoing.
What is the difference between pernicious anaemia and B12 deficiency?
Pernicious anaemia is one cause of B12 deficiency — an autoimmune one where the body cannot absorb B12. B12 deficiency can also result from low dietary intake or other absorption problems.
Sources
Where this is drawn from
- NHS — Vitamin B12 or folate deficiency anaemia
- British Society for Haematology guidance
Related conditions
Browse by body system
Building a patient-information or formulary resource?
We create evidence-led, dose-free clinical references and decision aids for teams.