Drug Interaction:
Excercise caution when administering other cyanide antidotes simultaneously with hydroxocobalamin
because safety of coadministration has not been established
If a decison a taken to administer another cyanide antidote with hydroxocobalamin do not
administer these drugs concurrently with the same IV line
Lab test abnormalites- because of its deep red color , hydroxocobalamin has been found to interfere
with coloroimetric determination of certain laboratory parameters eg clinical chemistry, coagulation,
hematology, urine parameters
Indication:
Cyanide Poisoning
Adverse Reaction:
Serious adverse reactions- allergic reactions and increases in blood pressure.
Cardiovascular - blood pressure increased 18%
CNS- headache 6%
Dermatologic - erythema 94% rash 20%
GI - nausea 6%
Contra-Indications:
Special precautions-
Emergency patient management- in addition to hydroxocobalamin ,treatment of cyanide poisoning
must include immediate attention to airway patency, adequacy of oxygenation and hydration.
cardiovascular support and management of any seizure activity.
Consider decontamination basd on the same route of exposure.
Blood pressure changes- many patients with cyanide poisoning will be hypotensive however,
elevation in blood pressure have been observed in known or suspected cyanide poisoning
Hypersitivity reactions- use caution in management of patients with known anaphylactic reactions
to hydroxocobalamin or cyanocobalamin . Consider use of alterntive therapies if available.
Photosensitivity- hydroxocobalamin absorbs visible light in the ultravilolet spectrum. It has therefore
has the potential to cause photosensitivity.If skin redness predisoses to photosentivity advice
patients to avoid direct sun while their skin remains discolored.
Pregnancy- use hydroxocobalamin during pregnancy only if the potential risk justifies the potential
risk to the fetus.
Lactation- Beciause hydroxocobalamin may be administered in life-threatening conditions,
breast feeding is not contraindicated to its use. However, excercise caution following
hydroxocobalamin adminstration to a breast feeding woman.
Children- safety and efficacy of hydroxocobalamin have not been established in children
Dosages/ Overdosage Etc:
Indication-
Cyanide Poisoning
Dosage-
The starting dose for adults is 5g (ie, both 2.5g vials) administered as an intravenous IV infuson
over 15 minutes ( approx. 15mL/min ) ie 7.5 minutes/vial
Depending on the severity of poisoning and the clinical response a second dose of 5g may be
administered by IV infusion for a total dose of 10g.
The rate of second dose may range from 15 minutes ( for patients in extremis ) to 2 hours as
clinically indicated.
Patient Information:
1. Hydroxocobalamin is indicated for cyanide poisoning and in this setting patents will unlikely to
be responsive or may have diificulty in comprehending councelling information.
2. Advice patients that skin redness may last upto 2 weeks and urine colration may last upto
5 weeks after administration of hydroxocobalamin .
3. While it is not known if the skin redness predisposes to photosentivity , advice patients
to avoid direct sunlight while their skin remains discolored.
4. In some patients an acneform rash may appear anywhere from 7 to 28 days following
hydroxocobalamin treatment. This rash usually resolve without treatment within a few weeks.
5. Vitamin B12 excreted in humam milk . It is not known whether hydroxocobalamin is excreted
in human milk. Therefore, discuss if and when to resume breast-feeding in a breast-feeding
mother after hydroxocobalamin use.
Pharmacology/ Pharmacokinetics:
Pharmacology-
Cyanide is an extremely toxic poison . In the absence of rapid and adequate treatment , exposure to
high dose of cyanide can result in death within minutes due to inhibition of cytochrome oxidase,
resulting in arrest of cellular respiration
Pregnancy and lactation:
Pregnancy-
Use hydroxocobalamin during pregnancy only if the potential risk justifies the potential
risk to the fetus.
Lactation-
Beciause hydroxocobalamin may be administered in life-threatening conditions,
breat feeding is not contraindicated to its use. Howver, excercise caution following
hydroxocobalamin adminstration to a breast feeding woman.
Children-
Safety and efficacy of hydroxocobalamin have not been established in children