Hydroxocobalamin

Hydroxocobalamin is a manufactured version of the vitamin B12. It's used to treat and prevent vitamin B12 deficiency anaemia, where you have low levels of this vitamin in your body.

Your body requires vitamin B12 to make red blood cells. You can get it from your food or supplements, but sometimes there may not be enough vitamins in what you eat. This can happen if you are vegan or you do not eat much meat or dairy products.

The most common cause of vitamin B12 deficiency in the UK is pernicious anaemia (an autoimmune condition that affects your stomach).

Vitamin B12 deficiency can also be a side effect of metformin, a diabetes medicine, particularly if you take a high dose of metformin or if you take it for a long time.

Hydroxocobalamin is only available on prescription.

It is given as an injection. This will usually be at your GP surgery but you might sometimes have it in hospital.

Most adults and children can have hydroxocobalamin injections.

Hydroxocobalamin is not suitable for some people. To make sure it's safe for you, tell your doctor before having hydroxocobalamin if you:

• have ever had an allergic reaction to hydroxocobalamin or any other medicine
• have an allergy to cobalt
• have been told you have low levels of potassium
• have an irregular or fast heartbeat (arrhythmia)

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.

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.

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.

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.

There are things you can do to help cope with these common side effects of hydroxocobalamin:

These symptoms are usually mild and should only last a few hours. You can ask a pharmacist to recommend a mild painkiller if the pain is bothering you.

Stick to simple meals and avoid rich or spicy food. If you're being sick, try small, frequent sips of water to avoid dehydration.

If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Drink plenty of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark strong-smelling pee.

If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller.

Talk to your doctor if the headaches are severe or last longer than a few days.

Stop what you're doing, and sit or lie down until you feel better. Do not drive, ride a bike or use tools or machinery until you stop feeling dizzy.

Try cutting down on alcohol and drinks containing caffeine, such as tea, coffee, cola and energy drinks. It might help to use a fan to keep the room cool. You could also spray your face with cool water or sip cold or iced drinks.

The flushing should go away after a few days. If it does not go away, or if it's causing you problems, contact your doctor.

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects are very rare.

Tell your doctor or call 111 immediately if you get irregular heartbeats or heartbeats that suddenly become more noticeable (palpitations) after having treatment.

As hydroxocobalamin contains cobalt, it can cause sensitivity reactions in people who have an allergy to cobalt. Symptoms can start straight away or up to 3 days after having a dose. Talk to your doctor or call 111 if you get an allergic skin reaction such as a rash or hives.

Serious allergic reaction

In rare cases, hydroxocobalamin can cause a serious allergic reaction (anaphylaxis).

Call 999 now if:

• your lips, mouth, throat or tongue suddenly become swollen
• you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
• your throat feels tight or you're struggling to swallow
• your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
• you suddenly become very confused, drowsy or dizzy
• someone faints and cannot be woken up
• a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of hydroxocobalamin. For a full list, see the leaflet inside your medicine's packet.

Hydroxocobalamin can be used during pregnancy.

It's important that a vitamin B12 deficiency is correctly treated to make sure that you and your baby are healthy.

You can have hydroxocobalamin while you're breastfeeding.

Hydroxocobalamin is a natural part of breast milk. When you have hydroxocobalamin injections as a supplement or treatment, it passes into your breast milk in low amounts and helps your baby to stay healthy.

If your baby also has vitamin B12 deficiency, they will still also need treating themselves.

If you notice your baby is not feeding as well, or you have any concerns about your baby, contact your doctor, pharmacist, health visitor or midwife.

There's no evidence to suggest that taking hydroxocobalamin affects fertility in either men or women.

Tell your doctor if you're:

• trying to get pregnant
• pregnant
• breastfeeding

Hydroxocobalamin is usually safe to have with other medicines, including painkillers.

There's not enough information to say that complementary medicines, herbal remedies and supplements are safe to take with hydroxocobalamin. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.