Hydroxocobalamin
FDA Drug Information • Also known as: Cyanokit, Hydroxocobalamin
- Brand Names
- Cyanokit, Hydroxocobalamin
- Dosage Form
- POWDER
- Product Type
- BULK INGREDIENT
Description
11 DESCRIPTION Hydroxocobalamin, the active ingredient in CYANOKIT, is cobinamide dihydroxide dihydrogen phosphate (ester), mono (inner salt), 3'-ester with 5,6-dimethyl-1-α-D-ribofuranosyl-1H-benzimidazole, an antidote. The drug substance is the hydroxylated active form of vitamin B 12 and is a large molecule in which a trivalent cobalt ion is coordinated in four positions by a tetrapyrol (or corrin) ring. It is a hygroscopic, odorless, dark red, crystalline powder that is freely soluble in water and ethanol, and practically insoluble in acetone and diethyl ether. Hydroxocobalamin has a molecular weight of 1346.36 atomic mass units, an empirical formula of C 62 H 89 CoN 13 O 15 P and the following structural formula: CYANOKIT (hydroxocobalamin for injection) for intravenous infusion is a cyanide antidote package which contains one colorless 250 mL glass vial, containing 5 g dark red lyophilized hydroxocobalamin, pH adjusted with hydrochloric acid, one transfer spike, one intravenous administration set, one quick use reference guide and one package insert. The 5 g vial of hydroxocobalamin for injection is to be reconstituted with 200 mL of 0.9% NaCl, to give a dark red injectable solution (25 mg/mL). If 0.9% NaCl is not readily available, 200 mL of either Lactated Ringers injection or 5% Dextrose injection (D5W) may be used as the diluent. Diluent is not included in the CYANOKIT. The pH of the reconstituted product ranges from 3.5 to 6.0. structural formula
What Is Hydroxocobalamin Used For?
1 INDICATIONS AND USAGE CYANOKIT is indicated for the treatment of known or suspected cyanide poisoning. CYANOKIT is indicated for the treatment of known or suspected cyanide poisoning. ( 1 )
Dosage and Administration
2 DOSAGE AND ADMINISTRATION If clinical suspicion of cyanide poisoning is high, administer CYANOKIT without delay and in conjunction with appropriate airway, ventilatory, and circulatory support, oxygen administration as well as management of seizures. ( 2.1 ) The expert advice of a regional poison control center may be obtained by calling 1-800-222-1222. ( 2.1 ) Dosing : The starting dose of CYANOKIT for adults is 5 g, administered by intravenous infusion over 15 minutes. One 5 g vial is a complete starting dose. ( 2.2 ) Depending upon the severity of the poisoning and the clinical response, a second dose of 5 g may be administered by intravenous infusion for a total dose of 10 g. ( 2.2 ) The rate of infusion for the second 5 g dose may range from 15 minutes (for patients in extremis) to 2 hours based on patient condition. ( 2.2 ) The recommended diluent is 0.9% Sodium Chloride injection. ( 2.3 ) CYANOKIT requires a separate intravenous line for administration. ( 2.4 ) 2.1 Important Dosage and Administration Instructions If clinical suspicion of cyanide poisoning is high, administer CYANOKIT without delay. Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Airway, ventilatory and circulatory support, oxygen administration, and management of seizures should not be delayed to administer CYANOKIT [see Warnings and Precautions ( 5.1 )] . The expert advice of a regional poison control center may be obtained by calling 1-800-222-1222. Identifying Patients with Cyanide Poisoning Cyanide poisoning may result from inhalation, ingestion, or dermal exposure to various cyanide-containing compounds, including smoke from closed-space fires. Sources of cyanide poisoning include hydrogen cyanide and its salts, cyanogenic plants, aliphatic nitriles, and prolonged exposure to sodium nitroprusside. The presence and extent of cyanide poisoning are often initially unknown. There is no widely available, rapid, confirmatory cyanide blood test. Treatment decisions must be made on the basis of clinical history and signs and symptoms of cyanide intoxication. Table 1 Common Signs and Symptoms of Cyanide Poisoning Symptoms Headache Confusion Dyspnea Chest tightness Nausea Signs Altered Mental Status (e.g., confusion, disorientation) Seizures or Coma Mydriasis Tachypnea / Hyperpnea (early) Bradypnea / Apnea (late) Hypertension (early) / Hypotension (late) Cardiovascular collapse Vomiting Plasma lactate concentration ≥8 mmol/L In some settings, panic symptoms including tachypnea and vomiting may mimic early cyanide poisoning signs. The presence of altered mental status (e.g., confusion and disorientation) and/or mydriasis is suggestive of true cyanide poisoning although these signs can occur with other toxic exposures as well. Smoke Inhalation Not all smoke inhalation victims will have cyanide poisoning and may present with burns, trauma, and exposure to other toxic substances making a diagnosis of cyanide poisoning particularly...
Side Effects (Adverse Reactions)
6 ADVERSE REACTIONS Serious adverse reactions with hydroxocobalamin include allergic reactions, renal injury, and increases in blood pressure [see Warnings and Precautions ( 5.2 , 5.3 , 5.4 )]. Most common adverse reactions (>5%) include transient chromaturia, erythema, oxalate crystals in urine, rash, increased blood pressure, nausea, headache, and infusion site reactions. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS contact BTG at 1-877-377-3784, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Studies Experience Experience in Healthy Subjects Because clinical trials were conducted under widely varying conditions, adverse reaction rates observed in the clinical trials may not reflect the rates observed in practice. A double-blind, randomized, placebo-controlled, single-ascending-dose (2.5, 5, 7.5, and 10 g) study was conducted to assess the safety, tolerability, and pharmacokinetics of hydroxocobalamin in 136 healthy adult subjects. Because of the dark red color of hydroxocobalamin, the two most frequently occurring adverse reactions were chromaturia (red-colored urine) which was reported in all subjects receiving a 5 g dose or greater; and erythema (skin redness), which occurred in most subjects receiving a 5 g dose or greater. Adverse reactions reported in at least 5% of the 5 g dose group and corresponding rates in the 10 g and placebo groups are shown in Table 3 . Table 3 Incidence of Adverse Reactions Occurring in >5% of Subjects in 5 g Dose Group and Corresponding Incidence in 10 g Dose Group and Placebo * Rashes were predominantly acneiform ADR 5 g Dose Group 10 g Dose Group Hydroxocobalamin N=66 n (%) Placebo N=22 n (%) Hydroxocobalamin N=18 n (%) Placebo N=6 n (%) Chromaturia (red colored urine) 66 (100) 0 18 (100) 0 Erythema 62 (94) 0 18 (100) 0 Oxalate crystals in urine 40 (61) 1 (5) 10 (56) 0 Rash* 13 (20) 0 8 (44) 0 Blood pressure increased 12 (18) 0 5 (28) 0 Nausea 4 (6) 1 (5) 2 (11) 0 Headache 4 (6) 1 (5) 6 (33) 0 Lymphocyte percent decreased 5 (8) 0 3 (17) 0 Infusion site reaction 4 (6) 0 7 (39) 0 In this study, the following adverse reactions were reported to have occurred in a dose-dependent fashion and with greater frequency than observed in placebo-treated cohorts: increased blood pressure (particularly diastolic blood pressure), rash, nausea, headache and infusion site reactions. All were mild to moderate in severity and resolved spontaneously when the infusion was terminated or with standard supportive therapies. Other adverse reactions reported in this study and considered clinically relevant were: Eye disorders: swelling, irritation, redness Gastrointestinal disorders: dysphagia, abdominal discomfort, vomiting, diarrhea, dyspepsia, hematochezia General disorders and administration site conditions: peripheral edema, chest discomfort Immune system disorders: allergic reaction Nervous system disorders: memory impairment, dizziness Psychiatric disorders: restlessness Respiratory, thoracic and mediastinal disorders: dyspnea, throat tightness, dry throat Skin and subcutaneous tissue disorders: urticaria, pruritus Vascular disorders: hot flush Experience in Known or Suspected Cyanide Poisoning Victims Four open-label, uncontrolled, clinical studies (one of which was prospective and three of which were retrospective) were conducted in known or suspected cyanide-poisoning victims. A total of 245 patients received hydroxocobalamin treatment in these studies. Systematic collection of adverse events was not done in all of these studies and interpretation of causality is limited due to the lack of a control group and due to circumstances of administration (e.g., use in fire victims). Adverse reactions reported in these studies listed by system organ class included: Cardiac disorders: ventricular extrasystoles Investigations: electrocardiogram repolarization abnormality, heart rate increased Respiratory, thoracic, and mediastinal disorders: pleural effusion Adverse reactions common to both the...
Drug Interactions
7 DRUG INTERACTIONS Formal drug interaction studies have not been conducted with CYANOKIT. Interference with Laboratory Tests Because of its deep red color, hydroxocobalamin has been found to interfere with colorimetric determination of certain laboratory parameters (e.g., clinical chemistry, hematology, coagulation, and urine parameters). Be aware of this when reporting and interpreting laboratory results [see Warnings and Precautions ( 5.5 )].
Contraindications
4 CONTRAINDICATIONS None None ( 4 )
Pregnancy and Breastfeeding
8.1 Pregnancy Risk Summary Available data from cases reported in the published literature and postmarketing surveillance with CYANOKIT use in pregnant women are insufficient to identify a drug-associated risk for major birth defects, miscarriage, or adverse maternal and fetal outcomes. There are risks to the pregnant woman and fetus associated with untreated cyanide poisoning (see Clinical Considerations) . In animal studies, hydroxocobalamin administered to pregnant rats and rabbits during the period of organogenesis caused skeletal and soft tissue abnormalities, including alterations in the central nervous system, at exposures similar to human exposures at the therapeutic dose (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Cyanide readily crosses the placenta. Cyanide poisoning is a medical emergency in pregnancy which can be fatal for the pregnant woman and fetus if left untreated. Life-sustaining therapy should not be withheld due to pregnancy. Data Animal Data In animal studies, pregnant rats and rabbits received CYANOKIT (75, 150, or 300 mg/kg/d) during the period of organogenesis. Following intraperitoneal dosing in rats and intravenous dosing in rabbits, maternal exposures were equivalent to 0.5, 1, or 2 times the human exposure at the therapeutic dose (based on AUC). In the high dose groups for both species, maternal toxicity occurred, and there was a reduced number of live fetuses due to embryofetal resorptions. In addition, decreased live fetal weight occurred in high dose rats, but not in rabbits. Incomplete skeletal ossification occurred in both...
Overdosage
10 OVERDOSAGE No data are available about overdose with CYANOKIT in adults. Should overdose occur, treatment should be directed to the management of symptoms. Hemodialysis may be effective in such a circumstance, but is only indicated in the event of significant hydroxocobalamin-related toxicity. Because of its deep red color, hydroxocobalamin may interfere with the performance of hemodialysis machines [see Warnings and Precautions ( 5.5 )].
How Supplied
16 HOW SUPPLIED/STORAGE AND HANDLING Each CYANOKIT carton (NDC 50633-310-11) consists of the following: One 250 mL glass vial, containing lyophilized hydroxocobalamin for injection, 5 g One sterile transfer spike One sterile intravenous infusion set One quick use reference guide One package insert Diluent is not included. Storage Lyophilized form Store at 25°C (77°F); excursions permitted to 15-30°C (59 to 86°F) [see USP Controlled Room Temperature]. CYANOKIT may be exposed during short periods to the temperature variations of usual transport (15 days submitted to temperatures ranging from 5 to 40°C (41 to 104°F), transport in the desert (4 days submitted to temperatures ranging from 5 to 60°C (41 to 140°F)) and freezing/defrosting cycles (15 days submitted to temperatures ranging from -20 to 40°C (-4 to 104°F)). Reconstituted solution Store up to 6 hours at a temperature not exceeding 40ºC (104°F). Do not freeze. Discard any unused portion after 6 hours.
About This Information
This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.
What are side effects?
Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.
What are drug interactions?
Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.