Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Hydroxocobalamin 1mg/ml Solution for Injection
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Hydroxocobalamin acetate may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
FOR This medicine contains Hydroxocobalamin which is a form of Vitamin B12. Vitamin B12 contains cobalt. Hydroxocobalamin is given for:
- Addisonian pernicious anaemia (caused when absorption of Vitamin B12 from the stomach is reduced).
- Tobacco amblyopia (poor sight caused by toxins such as tobacco).
- Leber's atrophy (degeneration of the optic nerve resulting in loss of central vision).
- Treatment/prevention of other macrocytic anaemias due to deficiency in vitamin B12. Vitamin B12 is needed for physical growth and development and for the formation of red blood cells in the bone marrow. It is also required for absorption of folic acid and carbohydrates from food and for keeping the nerve (neurological) system healthy. The body only requires a small amount of the vitamin daily so a deficiency may take months or even years to develop. Eventually, the formation of abnormally large red blood cells (macrocytes) with reduced ability to carry oxygen from enlarged cells (megaloblasts) in the bone marrow, gives rise to anaemia. Symptoms of Vitamin B12 deficiency anaemia include sore mouth and tongue, numbness and tingling in the arms and legs, memory loss and depression.
What you need to know before you take it
HYDROXOCOBALAMIN INJECTION Do not use Hydroxocobalamin Injection:
- if you are allergic to the active substance or any of the other ingredients of this medicine (listed in section 6). Warnings and precautions: Tell your doctor, pharmacist or nurse before you are given Hydroxocobalamin injection:
- If you are aware of abnormal heart beats whilst receiving Hydroxocobalamin injections.
- If, after several weeks' treatment you do not feel any improvement.
- if you have a known cobalt allergy.
Other medicines and Hydroxocobalamin injection Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. Hydroxocobalamin injection can interfere with the action of some other drugs and some drugs can have an effect on Hydroxocobalamin injection. The following drugs can cause some problems when taken together with Hydroxocobalamin Injection:
- chloramphenicol (an antibiotic) can reduce the effects of Hydroxocobalamin injection.
- oral contraceptives may reduce the blood levels of Hydroxocobalamin injection. The following medicines do not alter the effectiveness of Hydroxocobalamin Injection but make it more difficult to measure the amount of Vitamin B12 in the body:
- antibiotics.
- antimetabolites (used to treat tumours and blood disorders). Pregnancy, breast feeding and fertility If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine. Pregnancy Hydroxocobalamin injection should not be used for the treatment of megaloblastic anaemia of pregnancy. Breast feeding If you are breast feeding you should tell your doctor before you are given this medicine. Hydroxocobalamin injection passes into the breast milk but is unlikely affect your baby. Fertility No data available Driving and using machines Your medicine is unlikely to affect your ability to drive or to operate machinery. However, some people may feel dizzy or drowsy when given Hydroxocobalamin injection. If this happens to you, do not drive or operate machinery. Hydroxocobalamin injection contains sodium Hydroxocobalamin injection contains less than 1mmol (23mg) of sodium per 2ml , that is to say essentially 'sodium-free'.
How to take it
TO YOU Always use this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. Hydroxocobalamin will be given to you by injection into a muscle. The dose depends on your individual needs and responses to treatment. Your blood levels of Vitamin B12 and folic acid are likely to be monitored both before and during treatment. If you have doubts about the treatment or want more information about your medicine or the monitoring procedure, do ask the doctor or nurse. The recommended dose is Adults and Children
Initial dose: This varies between 250 mcg and 1mg given daily or on alternative days. The actual dosage depends on your specific illness and your response to treatment. Maintenance dose: Your doctor will check your condition regularly. When he/she feels that your health has improved sufficiently, your dose of Hydroxocobalamin Injection will be reduced to 1mg every 2-3 months or as required. If more Hydroxocobalamin injection is used than should be: Being given more than the intended dose of hydroxocobalamin injection is unlikely to cause a problem requiring treatment. Tell the doctor if you are experiencing any side effects or think you may be reacting badly so that he/she can give appropriate treatment. If you have already left the medical premises, contact your nearest hospital, doctor or nurse. If a dose of Hydroxocobalamin Injection is forgotten: It is unlikely that you will miss a dose as your doctor or nurse will be giving it to you. However, it is important not to have a double dose if you have missed one. Ask your doctor or nurse when you should have the next dose. If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.
Possible side effects
Like all medicines this medicine, can cause side effects, although not everybody gets them. Tell your doctor immediately if you experience any of the following symptoms after you have been given the injection. Although they are very rare, these symptoms can be serious.
- swelling of the lips and face, difficulty in breathing, skin rash and redness (these may be symptoms of a serious allergic reaction)
- irregular heartbeat (caused by low levels of potassium in the blood) during early stages of treatment. Rare: may affect up to 1 in 1,000 people
- Acniform and bullous eruptions (acne-like and blistery skin eruptions) Not known: frequency cannot be estimated from the available data
- Headache, dizziness
- Nausea (feeling sick), vomiting, diarrhoea
- Malaise (feeling unwell)
- Rash, itching
- Injection site reactions including injection site pain, injection site erythema, injection site pruritus, injection site induration, and injection site swelling (Reactions at the site of the injection)
- Exanthema (a widespread skin rash)
- Chromaturia (unusual coloured urine)
- Fever
- Hot flushes (a feeling of intense heat with sweating and rapid heartbeat)
- Chills (feeling of coldness accompanied by shivering)
- Paraesthesia (feeling of pins and needles)
- Tremor (tremble or shakes)
- Hypokalaemia (decreased potassium levels in the blood)
- Reactive thrombocytosis (body produces too many platelets) Reporting of side effects If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store By reporting side effects you can help provide more information on the safety of this medicine.
How to store it
HYDROXOCOBALAMIN INJECTION Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the label and carton after "EXP". The expiry date refers to the last day of that month. Do not store above 25°C. Keep the ampoule in the outer carton in order to protect from light. If only part used, discard the remaining solution. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
Contents of the pack and other information
What Hydroxocobalamin injection contains The active substance is Hydroxocobalamin. The other ingredients are sodium chloride, glacial acetic acid in water for injections. What Hydroxocobalamin injection looks like and contents of pack Hydroxocobalamin injection is a sterile solution for injection. Each glass ampoule contains 1ml of solution, which contains the active ingredient hydroxocobalamin acetate (equivalent to hydroxocobalamin 1mg in 1ml sterile solution). Each carton contains five 1ml ampoules. Marketing Authorisation Holder Mercury Pharmaceuticals Ltd., Dashwood House, 69 Old Broad Street, London, EC2M 1QS, United Kingdom Manufacturer Delpharm Tours, Rue Paul Langevin, 37170 Chambray Lès Tours, France. This leaflet was last revised in January 2024.
Frequently asked questions about Hydroxocobalamin 1mg/ml Solution for Injection
How do I take Hydroxocobalamin 1mg/ml Solution for Injection?
Hydroxocobalamin 1mg/ml Solution for Injection comes as injection containing 1mg/ml. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
What is the active substance in Hydroxocobalamin 1mg/ml Solution for Injection?
The active substance in Hydroxocobalamin 1mg/ml Solution for Injection is hydroxocobalamin acetate.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for Hydroxocobalamin 1mg/ml Solution for Injection, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get Hydroxocobalamin 1mg/ml Solution for Injection without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: hydroxocobalamin acetate
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
1. Name of the medicinal product
Hydroxocobalamin 1mg/ml Solution for Injection
2. Qualitative and quantitative composition
| Active Substance | Quantity | Reference Standard |
| Hydroxocobalamin Acetate | 1.04 mg | Ph Eur |
| equivalent to | ||
| Hydroxocobalamin | 1.00 mg |
Hydroxocobalamin contains cobalt.
For the full list of excipients, see section 6.1.
3. Pharmaceutical form
Solution for Injection
4. Clinical particulars
4.1. Therapeutic indications
Addisonian pernicious anaemia. Prophylaxis and treatment of other macrocytic anaemias associated with vitamin B12 deficiency. Tobacco amblyopia and Leber's optic atrophy
4.2. Posology and method of administration
Posology
Adults and Paediatric population
The following dosage are suitable for adults and children.
Addisonian pernicious anaemias and other macrocytic anaemias without neurological involvement.
Initially 250 to 1000 micrograms intramuscularly on alternate days for one or two weeks, then 250 micrograms weekly until the blood count is normal
Maintenance: 1000 micrograms every two to three months
Addisonian pernicious anaemia and other macrocytic anaemias with neurological involvement
Initially: 1000 micrograms on alternate days as long as improvement is occurring. Maintenance:1000 micrograms every two of three months.
Prophylaxis of macrocytic anaemia associated with vitamin B12 deficiency resulting from gastrectomy, some malabsorption syndromes and strict vegetarianism
1000 micrograms every two or three months. Tobacco amblyopia and Leber's optic atrophy
Initially: 1000 micrograms daily by intramuscular injection for two weeks then twice weekly as long as improvement is occurring.
Maintenance: 1000 micrograms every one to three months as required.
Method of Administration
Intramuscular injection
4.3. Contraindications
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.
4.4. Special warnings and precautions for use
It is advisable to confirm the diagnosis of Vitamin B12 deficiency before giving hydroxocobalamin; regular monitoring of the blood is recommended..
If megaloblastic anaemia fails to respond, folate metabolism should be investigated. Doses in excess of 10 micrograms daily may produce a haematological response in patients with folate deficiency. Indiscriminate administration may mask the true diagnosis.
Cardiac arrhythmias secondary to hypokalaemia during initial therapy have been reported. Plasma potassium should therefore be monitored during this period.
4.5. Interaction with other medicinal products and other forms of interaction
Chloramphenicol
Parenteral chloramphenicol may attenuate the effect of hydroxocobalamin in anaemia.
Oral contraceptives
The serum concentration of hydroxocobalamin may be lowered.
The above interactions are unlikely to be of clinical significance but should be taken into account when performing assays for blood concentrations.
Vitamin B12 assays by microbiological techniques are invalidated by antimetabolites and most antibiotics.
Paediatric population
Interaction studies have only been performed in adults.
4.6. Fertility, pregnancy and lactation
Pregnancy
Hydroxocobalamin injection should not be used for the treatment of megaloblastic anaemia of pregnancy.
Breast-feeding
Hydroxocobalamin is secreted into breast milk but is unlikely to harm the infant.
Fertility
No data available
4.7. Effects on ability to drive and use machines
Not relevant.
4.8. Undesirable effects
The following adverse reactions are classified by system organ class and ranked under heading of frequency using the following convention:
Not known (cannot be estimated from the available data)
There are no modern clinical studies available that can be used to determine the frequency of undesirable effects. Therefore, all the undesirable effects listed are classed as “frequency Not Known”.
The following effects have been reported and are listed below by body system:
| System organ class | Frequency | Undesirable effects |
| Blood and lymphatic system disorders | Not Known | Reactive thrombocytosis can occur during the first weeks of use in megaloblastic anaemia. |
| Immune system disorders | Not Known | Hypersensitivity reactions including rash; itching; exanthema. Antibodies to hydroxocobalamin-transcobalamin II complex have developed during hydroxocobalamin therapy. Anaphylaxis |
| Metabolism and nutrition disorders | Not Known | Initial hypokalaemia |
| Nervous system disorders | Not Known | Headache, paraesthesia, tremor. |
| Cardiac disorders | Not Known | Arrhythmias secondary to hypokalaemia. |
| Gastrointestinal disorders | Not Known | Nausea, vomiting, diarrhoea. |
| General disorders and administration site conditions | Not Known | Fever, chills, hot flushes; dizziness; malaise; pain; Injection site reactions including injection site pain, injection site erythema, injection site pruritus, injection site induration, and injection site swelling. |
| Skin and subcutaneous tissue disorders | Not Known | Acneiform and bullous eruptions |
| Renal and urinary disorders | Not Known | Chromaturia |
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store
4.9. Overdose
Treatment is unlikely to be required in the case of overdose.
5. Pharmacological properties
5.1. Pharmacodynamic properties
Pharmacotherapeutic group: Antianaemic preparations -Vitamin B12
ATC code: B03BA03
Hydroxocobalamin is used in the treatment and prevention of Vitamin B12 deficiency. For adults, the daily requirement of Vitamin B12 is probably about 1 to 2 micrograms and this amount is present in most normal diets. However, Vitamin B12 only occurs in animal products, not in vegetables, and therefore strict vegetarian or vegan diets that exclude dairy products may provide an inadequate amount, although a deficiency may not be apparent for many years.
Deficiency is more likely in patients with malabasorption syndromes or metabolic disorders, nitrous-oxide induced megalobastosis, or following gastrectomy or extensive ileal resection. Deficiency leads to megaloblastic anaemias and demyelination and other neurological damage.
On oral intake, Vitamin B12 substances bind to intrinsic factor, a glycoprotein secreted by the gastric mucosa, and are then actively absorbed from the gastrointestinal tract. A specific anaemia known as pernicious anaemia develops in patients with an absence of intrinsic factor. Absorption is also impaired in patients with disease or abnormality of the gut.
Treatment usually results in rapid haematological improvement and a striking clinical response. However, neurological symptoms respond more slowly.
5.2. Pharmacokinetic properties
Distribution
Transcobalamin II appears to be involved in the rapid transport of the cobalamins to tissues. Hydroxocobalamin is extensively bound to specific plasma proteins (transcobalamins).
Elimination
Hydroxocobalamin is stored in the liver, excreted in the bile, and undergoes extensive enterohepatic recycling; part of the dose is excreted in the urine, most of it in the first 8 hours.
Hydroxocobalamin diffuses across the placenta and also appears in breast milk. Hydroxocobalamin is better retained than cyanocobalamin; 90% of a 100 microgram dose and 30% of a 1000 microgram dose are retained, a range believed to be sufficient for body requirements for 2 to 10 months.
5.3. Preclinical safety data
There is no additional information relevant to the prescriber.
6. Pharmaceutical particulars
6.1. List of excipients
Glacial acetic acid Ph Eur
Sodium chloride Ph Eur
Water for injection Ph Eur
6.2. Incompatibilities
Not applicable.
6.3. Shelf life
2 years
6.4. Special precautions for storage
Store at or below 25ºC. Protect from light.
6.5. Nature and contents of container
Type I glass ampoules in cardboard box.
5 ampoules per pack.
6.6. Special precautions for disposal and other handling
No special requirements.
7. Marketing authorisation holder
Mercury Pharmaceuticals Ltd,
Dashwood House,
69 Old Broad Street,
London, EC2M 1QS, United Kingdom
8. Marketing authorisation number(s)
PL 12762/0008
9. Date of first authorisation/renewal of the authorisation
18 August 1997
10. Date of revision of the text
23/01/2024
🇵🇱 Known in Poland as
Medicines sold in Poland with the same active substance: W Polsce znany jako
- CyanokitHydroxocobalaminum · injection / infusion
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Polish medicines in the UK →
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Ask anything about Hydroxocobalamin 1mg/ml Solution for Injection. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.