Hydroxocobalamin

What hydroxocobalamin is for

Hydroxocobalamin is a man-made (artificial) version of vitamin B12. It's used to treat and prevent vitamin B12 deficiency, which happens when you have low levels of this vitamin in your body.

Your body needs vitamin B12 to make red blood cells. Red blood cells carry oxygen around the body.

You can get vitamin B12 from your food or supplements, but sometimes you might not be able to get enough. This can happen if you have a condition that affects how your body absorbs vitamin B12, you have a vegan diet, or you do not eat much meat or dairy products.

How hydroxocobalamin is given

Hydroxocobalamin comes as an injection. Your GP can give you the injection, but sometimes you might have it in hospital.

You'll usually start by having a few injections a week. As your symptoms get better, you might only have one every 2 to 3 months.

You may be able to stop having hydroxocobalamin injections when your vitamin B12 blood levels are back to normal. However, you may need to have them for the rest of your life if you cannot absorb enough vitamin B12 from your food or because of a condition.

If you miss a dose of hydroxocobalamin

If you miss your injection, the level of vitamin B12 in your body may go down further. This may make your symptoms worse.

Ask your doctor when you will have your next dose.

Side effects of hydroxocobalamin

Like all medicines, hydroxocobalamin can cause side effects, although not everyone gets them.

Side effects of hydroxocobalamin include:

• pain, swelling or itchy skin where you had the injection
• feeling or being sick (nausea or vomiting)
• diarrhoea
• headaches
• dizziness
• hot flushes

Serious side effects

Hydroxocobalamin can sometimes cause serious side effects, although most of them are rare.

Possible serious side effects of hydroxocobalamin include:

• an allergic reaction (anaphylaxis) – causing symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathing
• irregular heartbeats (arrhythmia) or heartbeats that suddenly become more noticeable (palpitations)
• skin reactions – causing symptoms such a rash with blisters, feeling faint, wheezing or difficulty breathing

Who can and cannot have hydroxocobalamin

Most adults and children can have hydroxocobalamin injections.

But hydroxocobalamin is not suitable for everyone. For example, it may not be suitable if:

• you've had an allergic reaction or other serious side effect from hydroxocobalamin
• you're allergic to cobalt

Before having hydroxocobalamin, tell your doctor if you have any medical conditions.

Breastfeeding and hydroxocobalamin

You may be able to have hydroxocobalamin injections while you're breastfeeding, but check with a pharmacist or doctor first.

It's rare for breastfed babies to get any side effects from medicine you're taking, but speak to a healthcare professional if you have any concerns about your baby or call NHS 111.

Pregnancy and hydroxocobalamin

You can usually have hydroxocobalamin injections if you're pregnant, but check with your pharmacists or doctor first.

Find out more about taking hydroxocobalamin during pregnancy on the Bumps (Best Use of Medicines in Pregnancy) website

Having hydroxocobalamin with other medicines, food and drink

There are some medicines, remedies and supplements that may not mix well with hydroxocobalamin, including oral contraceptives.

Before having hydroxocobalamin injections, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.

Food, drink and alcohol with hydroxocobalamin

You can eat and drink as normal while having hydroxocobalamin.