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Cyanokit Side Effects

Generic name: hydroxocobalamin

Medically reviewed by Last updated on Feb 12, 2024.

Note: This document contains side effect information about hydroxocobalamin. Some dosage forms listed on this page may not apply to the brand name Cyanokit.

Applies to hydroxocobalamin: intravenous powder for solution.

Serious side effects of Cyanokit

Along with its needed effects, hydroxocobalamin (the active ingredient contained in Cyanokit) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking hydroxocobalamin:

More common

Incidence not known

Other side effects of Cyanokit

Some side effects of hydroxocobalamin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Incidence not known

For Healthcare Professionals

Applies to hydroxocobalamin: compounding powder, injectable solution, intravenous powder for injection.


Ventricular extrasystoles, electrocardiogram repolarization abnormality, and heart rate increased were seen in known/suspected cyanide poisoning patients.[Ref]

Very common (10% or more): Blood pressure increased (28% with 10 gram dose)

Frequency not reported: Increased blood pressure (particularly diastolic), hot flush, ventricular extrasystoles, electrocardiogram repolarization abnormality, heart rate increased[Ref]


Very common (10% or more): Nausea (11% with 10 gram dose)

Frequency not reported: Dysphagia, abdominal discomfort, vomiting, diarrhea, dyspepsia, hematochezia[Ref]


Very common (10% or more): Erythema (100% with 10 gram dose), rash (primarily acneiform) (44% with 10 gram dose)

Frequency not reported: Urticaria, pruritus[Ref]


Very common (10% or more): Chromaturia (red colored urine) (100% with 5 or 10 gram dose), oxalate crystals in urine (61% with 5 gram dose)

Postmarketing reports: Urine calcium oxalate crystals[Ref]


Very common (10% or more): Lymphocyte count decreased (17% with 10 gram dose)[Ref]


Very common (10% or more): Infusion site reaction (39% with 10 gram dose)[Ref]


Postmarketing reports: Acute renal failure with acute tubular necrosis, renal impairment[Ref]

Nervous system

Very common (10% or more): Headache (33% with 10 gram dose)

Frequency not reported: Memory impairment, dizziness[Ref]


Frequency not reported: Dyspnea, throat tightness, dry throat, pleural effusion[Ref]

Pleural effusion was seen in known/suspected cyanide poisoning patients.[Ref]


Frequency not reported: Allergic reaction[Ref]


Frequency not reported: Swelling, irritation, redness[Ref]


Frequency not reported: Peripheral edema, chest discomfort[Ref]


Frequency not reported: Restlessness[Ref]


1. (2011) "Product Information. Cyanokit (hydroxocobalamin)." Meridian Medical Technologies Inc

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.