Dosage
When you first start having your hydroxocobalamin treatment, you'll usually have an injection a few times a week.
Your dose may go up or down, depending on your response to the treatment and the vitamin B12 levels in your blood.
To see how well it's working, your doctor will ask you about your symptoms such as tiredness and lack of energy. They will also give you regular blood tests to monitor the vitamin B12 levels in your blood.
As your symptoms and vitamin B12 levels improve, you may be able to have the injections less often, such as every few months.
How you will have it
A nurse, or possibly a doctor, will usually give you your hydroxocobalamin injection. The injection is given into a muscle (known as an intramuscular injection).
You may have some pain, swelling or itching where you had the injection. This is usually mild and will wear off quite quickly.
How long you'll have it for
Your doctor will decide exactly how long you will need to have hydroxocobalamin injections. It depends on how well you respond to your treatment.
It will usually be a few months or sometimes years.
For pernicious anaemia, you'll need to take hydroxocobalamin for the rest of your life.
If you miss an injection
It's important to go to your appointments.
If you miss having your injection, the level of vitamin B12 in your body will go down further. This may make your health problems worse.
If you do have to miss an appointment, ask your doctor or nurse when you should have the next dose.