vitamin-b-12 and Poisoning

Topics: Carbon Dioxide; Cobalt; Cyanides; Edetic Acid; Electron Transport Complex IV; Ferricyanides; Hemoglobins; Histidine; Humans; Poisoning; Thiocyanates; Vitamin B 12

Topics: Animals; Biotransformation; Chemical Phenomena; Chemistry; Glycosides; Humans; Hydrogen Cyanide; Liver; Methylene Blue; Nitrites; Plants; Poisoning; Thiocyanates; Thiosulfates; Vitamin B 12

To assess the relationship between blood pressure changes following infusion of antidotal doses of hydroxocobalamin and plasma concentrations of total and free cobalamins-(III).. Independent groups of healthy volunteers received single intravenous doses of 2.5, 5, 7.5, or 10 g hydroxocobalamin over 7.5 to 30 minutes.. In the pharmacokinetic population (n = 41), hydroxocobalamin caused short-lived mean blood pressure increases. Blood pressure increased shortly after initiation of infusion and returned nearly to baseline by 4 hours post-infusion. The time course of blood pressure changes coincided with that of changes in plasma total and free cobalamins-(III). Change in mean arterial pressure (MAP) was strongly correlated with plasma area-under-the-concentration-time curves (AUCs) of total and free cobalamins-(III) during infusion (r > 0.7) but not through 24 hours post-infusion (r < or = 0.36).. The short-lived increase in mean blood pressure during administration of antidotal doses of hydroxocobalamin is closely linked to initial exposure to total and free cobalamins-(III).

Topics: Adult; Antidotes; Area Under Curve; Blood Pressure; Dose-Response Relationship, Drug; Female; Humans; Hydroxocobalamin; Infusions, Intravenous; Male; Middle Aged; Poisoning; Time Factors; Vitamin B 12

Ipecac-induced emesis and gastric lavage are the two procedures most widely used to evacuate the stomachs of patients who have ingested poisons. To resolve a long-standing controversy over the relative efficacy of these two methods, the authors carried out a controlled study in which they administered 25 100-micrograms tablets of cyanocobalamin (vitamin B12) to 18 fasting normal adult volunteers on two separate days. On one day, each subject had emesis induced with 30 ml of ipecac syrup followed by 1,000 ml of tap water; on another day, each underwent gastric aspiration and lavage with a 1.1-cm orogastric tube using 3 l of fluid. Both procedures were begun 10 minutes after the ingestion. The recovered vomitus or gastric washings from each procedure were then analyzed for elemental cobalt using atomic absorption spectrophotometry. The mean rate of recovery of the ingested tracer with ipecac-induced emesis was only 28%, whereas gastric lavage resulted in retrieval of 45% (paired t-test, P less than 0.005). In this study, carefully performed gastric lavage was the more effective method of gastric evacuation of tablets in the adult subject.

Topics: Adult; Clinical Trials as Topic; Cobalt; Female; Gastric Lavage; Humans; Ipecac; Male; Poisoning; Spectrophotometry, Atomic; Vitamin B 12; Vomiting

Chronic cyanide intoxication of dietary origin and riboflavine deficiency are believed to be major aetiological factors in Nigerian tropical ataxic neuropathy. The results are presented of a double-blind controlled therapeutic trial of combinations of large doses of hydroxocobalamin and cystine as cyanide binding agents together with riboflavine or placebos in Nigerian patients suffering from the tropical ataxic neuropathy. No clinical benefit was demonstrable with any of the treatments.

Topics: Ataxia; Cyanides; Cystine; Deafness; Evaluation Studies as Topic; Female; Humans; Hydroxocobalamin; Male; Middle Aged; Nigeria; Optic Atrophy; Peripheral Nervous System Diseases; Placebos; Poisoning; Riboflavin; Riboflavin Deficiency; Syndrome; Thiocyanates; Vitamin B 12

A 50-year-old man presented with a four-year history of unsteadiness, with recent falls and tingling in his fingers. Neurological examination found an ataxic gait, with a positive Romberg's sign. There was distal wasting and weakness in all four limbs and impaired co-ordination, with pseudoathetosis in the arms. Initial investigations showed a normochromic, normocytic anaemia, leucopenia, neutropenia and a low vitamin B(12) (172 ng/L). Treatment with intramuscular cobalamin injections showed no clinical improvement. Further investigations showed an undetectable caeruloplasmin (<0.085 g/L), a very low serum copper (1.1 μmol/L) and a markedly raised serum zinc concentration (36.2 μmol/L). On detailed questioning it became apparent that he had ill-fitting dentures requiring excessive use of denture fixative with high zinc content. The patient was switched to a non-zinc containing denture fixative and commenced copper supplementation. Although within three months the bone marrow suppression had resolved, there was no clinical improvement in neurological presentation. Questioning a patient about their denture fixative usage and checking if zinc is an ingredient may be considered during an investigation for myelopolyneuropathy when vitamin B(12) deficiency is not a cause.

Topics: Anemia; Ceruloplasmin; Copper; Dental Cements; Dentures; Diagnosis, Differential; Heavy Metal Poisoning; Humans; Male; Middle Aged; Neutropenia; Poisoning; Polyneuropathies; Vitamin B 12; Vitamin B 12 Deficiency; Zinc

Topics: Cyanides; Humans; Injections, Intravenous; Poisoning; Vitamin B 12

Hydroxocobalamin (OHCbl) is a powerful antidote for cyanide poisoning, via the formation of non-toxic cyanocobalamin (CNCbl). Plasmatic cobalamins were measured at 361 nm, after enrichment and purification on a short C18 precolumn (1% acetic acid; 1 ml min-1; 2 min), by back-flush elution on a C18 ODS-2 column [0.1 M sodium dihydrogenphosphate-methanol (63:27, v/v) (pH 4.0); 0.80 ml min-1]. The precision was 3.21 and 3.54% for 10 microM OHCbl and CNCbl, respectively. The method was used to study the pharmacokinetics of OHCbl and the formed CNCbl in severely poisoned patients.

Topics: Antidotes; Chromatography, High Pressure Liquid; Cyanides; Humans; Hydroxocobalamin; Luminescent Measurements; Poisoning; Scintillation Counting; Spectrophotometry, Ultraviolet; Vitamin B 12

In acute poisoning the main purpose of any therapeutic approach is a rapid removal of the drug or poison from body tissues. This approach suggested to undertake a study for the development of an uncoated activated carbon hemoperfusion column suitable for acute poisoning. Th clearances were significantly superior compared with a similar device manufactured using coated carbon. The microparticle generation, utilizing a spherical type of activated carbon, was undetectable with the adopted measuring method, well below the US and British Pharmacopeas limits and practically equal to a coated carbon column with identical geometry.

Topics: Acute Disease; Adsorption; Animals; Blood Glucose; Blood Urea Nitrogen; Carbon; Creatinine; Hemoperfusion; Humans; Inulin; Particle Size; Phenobarbital; Poisoning; Rabbits; Salicylates; Salicylic Acid; Uric Acid; Vitamin B 12

Topics: Acidosis; Adult; Cyanides; Cyanosis; Gastric Lavage; Gastrointestinal Hemorrhage; Humans; Hydrogen Cyanide; Hydrogen-Ion Concentration; Hydroxocobalamin; Hypotension; Liver; Middle Aged; Poisoning; Suicide; Time Factors; Vitamin B 12

Topics: Cyanides; Humans; Poisoning; Vitamin B 12

Topics: Adolescent; Butanones; Formaldehyde; Humans; Male; Methanol; Optic Neuritis; Poisoning; Prednisone; Solvents; Vitamin B 12; Vitamin B Complex

Topics: Adult; Amblyopia; Anemia, Pernicious; Child; Chloroquine; Craniocerebral Trauma; Cyanides; Female; Humans; Ischemia; Male; Methanol; Nerve Compression Syndromes; Optic Atrophy; Optic Chiasm; Optic Neuritis; Poisoning; Scotoma; Smoking; Syndrome; Syphilis; Vision Disorders; Vitamin B 12

Topics: Arsenic; Cortisone; Cytopathogenic Effect, Viral; Dexamethasone; Drug Therapy; Epidemiology; Erythromycin; Fluorescent Antibody Technique; Geriatrics; Herpes Zoster; Herpesvirus 3, Human; Humans; Hyaluronoglucosaminidase; Methicillin; Neuralgia; Neutralization Tests; Oxytetracycline; Poisoning; Prednisolone; Spironolactone; Vitamin B 12

Topics: Autonomic Nervous System Diseases; Barbiturates; Biomedical Research; Blood Chemical Analysis; Carbon Monoxide Poisoning; Cerebrovascular Disorders; Chemical Phenomena; Chemistry; Humans; Hydroxocobalamin; Mental Disorders; Neuralgia; Neuritis; Neurology; Pharmacology; Poisoning; Vitamin B 12

Topics: Anemia; Anemia, Pernicious; Brain Diseases; Cyanides; Delirium; Electroencephalography; Humans; Injections, Intramuscular; Lung Abscess; Male; Metabolism; Poisoning; Staphylococcal Infections; Toxicology; Vitamin B 12

Topics: Cysteine; Dimercaprol; Gastric Lavage; Heavy Metal Poisoning; Humans; Iodides; Magnesium Sulfate; Metals, Heavy; Methionine; Poisoning; Thallium; Thiamine; Toxicology; Vitamin B 12

Topics: Adrenocorticotropic Hormone; Anemia; Anemia, Myelophthisic; Anti-Bacterial Agents; Ascorbic Acid; Benzene; Biopsy; Blood Transfusion; Cortisone; Female; Hematologic Diseases; Hematology; Leukemia; Liver Extracts; Mortality; Occupational Diseases; Pathology; Poisoning; Prednisolone; Prednisone; Pregnancy; Pregnancy Complications; Pregnancy Complications, Hematologic; Tetracycline; Toxicology; Vasopressins; Vitamin B 12

Topics: Animals; Corrinoids; Heavy Metal Poisoning; Metals, Heavy; Poisoning; Rats; Selenium; Vitamin B 12; Vitamin B Complex

Topics: Arsenic; Arsenic Poisoning; Corrinoids; Fats; Hematinics; Humans; Lipid Metabolism; Lipotropic Agents; Poisoning; Thiamine; Vitamin B 12; Vitamin E; Vitamins

Topics: Corrinoids; Formates; Formic Acid Esters; Hematinics; Humans; Liver; Poisoning; Vitamin B 12

Topics: Ascorbic Acid; Benzene; Corrinoids; Hematinics; Poisoning; Poisons; Vitamin B 12; Vitamins