Hydroxocobalamin (Intravenous)

Most often used in an emergency for the treatment of cyanide poisoning, hydroxocobalamin is a known effective antidote which helps the body convert cyanide to a state which can easily be passed by urination.


Hydroxocobalamin is one of the most commonly used antidotes for counteracting the effects of cyanide poisoning, and it accomplishes this by quickly converting the cyanide in the body into a form which can safely and easily be passed out by urinating. There are several ways that a person could contract cyanide poisoning, even in a home setting.

Firstly, you might inhale an excessive amount of smoke from some kind of house fire or industrial fire, or you could accidentally swallow a quantity of cyanide, or the poison might be absorbed through the skin somehow. However the cyanide enters the body, it must be removed quickly, or serious consequences will develop, and one of the best ways to do this is to inject hydroxocobalamin immediately.

If you suspect someone has ingested cyanide, the warning signs include the following:

  • Tightness of the chest
  • Sudden confusion or disorientation
  • Sudden onset of nausea and or vomiting
  • Convulsions or seizures
  • Difficulty with breathing
  • Dilated or enlarged pupils.

This medication should only be administered under the direct supervision of a doctor or qualified medical professional. Although the usual circumstances for administration are in an emergency situation, it is still best to find someone quickly who has medical skills and can safely administer the needed dosage.

Condition Treated

  • Cyanide Poisoning
  • Vitamin B12 Deficiency

Type Of Medicine

  • Antidote (for cyanide poisoning)

Side Effects

Along with its life-saving medical benefits, there is a possibility that hydroxocobalamin may impart some undesirable side effects to the patient being ministered to. Even though there is a chance of some side effects being sustained by the patient, it is still much more desirable to deliver the dosage of hydroxocobalamin in order to potentially save the person's life. Some of the most common side effects which have been reported by patients who were treated with this medication include the following:

  • Blurred vision or double vision
  • Slow or fast heartbeat
  • Pounding in the ears
  • Nervousness or agitation
  • Dizziness or lightheadedness
  • Headaches
  • Redness of the skin
  • Tightness in the chest
  • Profuse sweating
  • Redness of the face, neck, arms, and upper chest
  • Sudden unexplained weight gain
  • Feeling of warmth
  • Difficulty with swallowing
  • Unusual weight loss
  • Uncharacteristic weakness or tiredness
  • Tingling or numbness in the hands or the feet
  • Swelling or puffiness of the eyelids, or around the face, lips, or tongue
  • Hives and or rashes appearing on the skin
  • Extreme itchiness at various locations around the body
  • Persistent coughing
  • Labored breathing
  • Nausea and/or vomiting
  • Sudden development of acne
  • Red colored urine
  • Blemishes on the skin
  • Dry or irritated skin
  • Restlessness
  • Stomach discomfort or pain
  • Indigestion or heartburn
  • Persistent diarrhea
  • Uncontrolled belching
  • Tendency toward unusual forgetfulness.

In addition, there are some side effects which may come and go of their own accord, and have a relatively little impact on patients, but which tend to be temporary expressions of the body adapting to an entirely new medication.


A typical dosage which would be administered to an adult in an emergency situation and who was suffering from cyanide poisoning would be administered directly into a vein for a period lasting between 10 and 15 minutes. There should be a significant noticeable improvement in the patient's condition very soon after administration of this medication, but it is always advisable to have a paramedic standing by for evacuation to a hospital if it should become necessary.

A standard dosage for an adult suffering from vitamin B12 deficiency, with uncomplicated disease status, would be the following:

  • An initial dosage of 30 µg intramuscular once a day for between five and 10 days
  • An alternative treatment program might be comprised of 100 micrograms delivered in intramuscular fashion, once a day for seven days, to be followed up with another 100 µg delivered via intramuscular route every other day for 14 days
  • An adult maintenance dosage would consist of between 100 to 200 µg, delivered in intramuscular fashion once a month

A standard adult dosage for an adult suffering from vitamin B12 deficiency, with complicated disease status, would include the following:

  • An initial dosage of 1000 µg, delivered in intramuscular fashion, to be accompanied by 15 mg of folic acid, and followed up with 100 µg administered daily in tandem with 5 mg of folic acid every day for one week
  • A maintenance dosage for the complicated disease status would be 100 to 200 µg delivered via intramuscular route once per month.


The likelihood of interaction between hydroxocobalamin and any other drugs is not as high as with many other medications since one of the primary usages of this drug is in an emergency situation to provide an antidote to cyanide poisoning. As such, it will generally be administered one time only, and will therefore have very little opportunity to interact with other drugs.

However, there are other situations which call for the injection of hydroxocobalamin, namely its usage in supplying needed vitamin B12 for patients who are lacking in that nutrient. If you are being treated for a vitamin B12 deficiency, it is advisable for you to prepare a list of all other medications which you are currently taking, including over-the-counter drugs, other prescription medications, herbal supplements, and other vitamins, as well as all of the dosages of these. Your doctor can review this list and determine whether or not there is a potential for drug interactions between hydroxocobalamin and any other drug on your list.

If there is potential for such interactions, they might take the form of imparting unwanted side effects to the patient, or the two drugs might act on each other so that either or both are diminished in effectiveness. Since neither one of these situations is desirable, drug interactions are to be avoided to the greatest extent possible.

The list which you prepare can also be used if you ever have to go to the emergency room for unscheduled treatment. A doctor there can evaluate your medication list and prescribe treatment which will not be in conflict with any of the other medications you're currently taking.


There are a few warnings or precautions which you should be aware of when being treated with hydroxocobalamin, and of course if you have received an emergency injection as an antidote, you won't have time to observe any of the warnings discussed below.

However, if you're being treated for some other condition such as vitamin B12 deficiency, you should be aware of a few precautions before agreeing to treatment with this medication. Your family doctor will probably want to check on your progress regularly to see if the medication is having the desired effect, and that it is not causing any significant side effects which are causing you discomfort. In some cases, your doctor may want to have blood tests taken to check the levels of various components in your bloodstream.

There's a potential for this medication to cause a serious allergic reaction, for instance anaphylaxis. This can be a life-threatening condition that requires emergency medical attention, so you should tell your doctor or anyone in the immediate area right away if you begin to experience the following:

  • Tightness in the chest
  • Extreme difficulty with breathing or swallowing
  • A pronounced swelling or puffiness in your eyelids, lips, tongue, or throat
  • Sudden appearance of rashes or hives on the skin.

There's also a possibility that hydroxocobalamin will trigger a low blood pressure situation in your body, and you should alert your doctor immediately if you detect an uneven heartbeat which you are unaccustomed to. You may also notice a fast, slow, or pounding heartbeat that is uncharacteristic for you.

Patients have reported redness of the skin after being treated with hydroxocobalamin, and it can also make your skin significantly more sensitive to direct sunlight. This condition may persist as long as two weeks following your treatment of hydroxocobalamin, so during that timeframe, it is advisable to avoid excessive exposure to sunshine, especially if your skin is already red. Take steps to protect your skin by using sunscreen or covering up as much exposed skin as is practical, and under no circumstances should you make visits to a tanning salon.

Hydroxocobalamin has been known to trigger a rash which has the appearance of acne, and which manifests itself somewhere between one and four weeks after being treated with the medicine. This rash will fade away generally without any kind of medical treatment, but if it persists or worsens in your own case, you should alert your doctor right away.


This medication should be stored in a safe location, well out of the reach of pets and children, in a room with temperature controls established between 68 degrees Fahrenheit and 77 degrees Fahrenheit. It is strongly advised to keep this medicine away from direct light and humidity, as it may degrade the medication. The medication should be inspected prior to administration to ensure that it has no floating particles in it and that it has not suffered discoloration. If either of these two conditions has occurred, the medicine should be disposed of in a safe manner and not used.


Hydroxocobalamin is a form of Vitamin B12, and as such, it is sometimes prescribed for patients who have a deficiency of that vitamin in their bodies. Another common usage for this medication is as an antidote to cyanide poisoning. It is delivered via injection directly into a muscle, and in the case of the antidote emergency, will only need to be given once. Patients being treated for Vitamin B12 deficiency will be treated by a doctor in an office or clinic setting, via injection.