Hydroxocobalamin

What is hydroxocobalamin?

Hydroxocobalamin is a synthetic form of vitamin B12. It is essential for producing red blood cells and maintaining a healthy nervous system. It is a prescription-only injection medicine given when your body cannot absorb enough B12 from food or oral supplements[1]. 

What is hydroxocobalamin used for?

Hydroxocobalamin is used for[1]: 

• Treating and preventing vitamin B12 deficiency anaemia 

• Managing pernicious anaemia, an autoimmune condition that interferes with B12 absorption 

• Occasionally treating cyanide poisoning in emergency settings  (using a form caused cyanokit®) 

How does hydroxocobalamin work?

Hydroxocobalamin restores vitamin B12 levels in the body. This helps the body produce healthy red blood cells, maintain proper nerve function and alleviate symptoms like fatigue, weakness, and neurological problems[1]. It is also required for absorption of folic acid and carbohydrates from food.   

Who can take hydroxocobalamin?

Most adults and children can take hydroxocobalamin. However, it may not be suitable for people who are allergic to hydroxocobalamin, cobalt or any other ingredients listed as part of your medicine. Tell your doctor, pharmacist or nurse if you have low potassium levels (hypokalaemia) or have a fast or irregular heartbeat[1]. 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the typical dosage of hydroxocobalamin?

Typical injection dosing schedules include[1]: 

• Initial treatment: 1mg injection three times a week for two weeks, however dose may vary 

• Maintenance treatment: 1mg every two to three months 

• For pernicious anaemia: lifelong treatment may be necessary 

How do you take hydroxocobalamin?

Hydroxocobalamin is given as an intramuscular injection[1]: 

• Injections are usually administered by a healthcare professional 

• Some patients may be trained to self-inject at home 

• Common injection sites include the thigh or upper arm 

Can you stop taking hydroxocobalamin?

You should not stop treatment without speaking to your doctor or pharmacist. Stopping can lead to a drop in B12 levels and a return of symptoms. If the deficiency is due to dietary causes, you may eventually switch to oral supplements (cyancobalamin) under medical supervision[1]. 

What do you do if you take too much hydroxocobalamin?

An overdose of hydroxocobalamin is extremely rare and usually not harmful. High doses are sometimes safely used in emergencies such as cyanide poisoning. If you are concerned, contact your GP or call 111[1]. 

What do you do if you forget to take hydroxocobalamin?

Missing a dose can allow your B12 levels to fall again. Contact your GP or pharmacist as soon as possible to reschedule. Do not double your next dose to make up for a missed one[1]. 

What medicines can’t you take with hydroxocobalamin?

Hydroxocobalamin is generally safe, but interactions may occur with[1]: 

• Metformin, which can reduce B12 levels 

• Chloramphenicol can reduce the effect of hydroxocobalamin injection 

• Oral contraceptives, which may slightly lower B12 levels 

• Medicines that affect potassium levels 

Please note this is not a complete list, always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of hydroxocobalamin?

The most common side effects of hydroxocobalamin include[1]: 

• Pain, swelling, or itching at the injection site 

• Nausea or diarrhoea 

• Headaches, dizziness, or hot flushes 

The rarer, but more serious side effect, would be an irregular heartbeat and you should tell your doctor or call 111 immediately if you believe you’re having more noticeable palpitations[1]. 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include[1]:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about hydroxocobalamin

How quickly does hydroxocobalamin work? 
The injection starts working immediately, but symptoms may take several days or weeks to improve[1]. 

Do I need hydroxocobalamin for life? 
Possibly, especially if you have pernicious anaemia or another long-term condition affecting B12 absorption[1]. 

Can I drink alcohol while receiving hydroxocobalamin? 
Yes, drinking alcohol in moderation is generally safe[1]. 

Can I drive after an injection? 
Yes, unless you feel dizzy or light-headed after the injection[1]. 

Does hydroxocobalamin affect contraception? 
No, it does not affect the effectiveness of birth control pills. However, vomiting or diarrhoea might reduce pill absorption, follow the advice included in your contraceptive Patient Information Leaflet[1]. 

Can I take hydroxocobalamin while pregnant? 
Yes, if your doctor has prescribed it, it is safe to use during pregnancy[1]. 

Is hydroxocobalamin vegan? 
It is synthetically made, but formulations may vary. Ask your pharmacist to confirm if it is suitable for vegans[1]. 

Can I switch from injections to tablets? 
Sometimes, especially if your body can absorb B12 from the digestive tract[1]. 

For the official NHS guide to hydroxocobalamin, visit their website.