ascorbic-acid and Drug-Overdose

The article presents the results of studies on potential risks associated with the abuse of vitamin supplements which until recently had been considered not only highly effica- cious, but also completely safe. Particular consideration is given to vitamins A, E, D and C. The necessity to control the intake of vitamin supplements and even to strictly super- vise the supply to high risk patients is highlighted.

Topics: Ascorbic Acid; Drug Overdose; Humans; Neoplasms; Risk Factors; Substance-Related Disorders; Vitamin A; Vitamin D; Vitamin E; Vitamins

A total of 15 patients with unilateral nephrostomy tubes after extracorporeal shock wave lithotripsy received either 0 (placebo), 100, 500, 1,000 or 2,000 mg. ascorbic acid on days 2 and 3 postoperatively. Before and after administration, successive 6-hour urine specimens were collected from the nephrostomy tube and from the contralateral kidney directly into a preservative to stabilize ascorbic acid and oxalate. In 1 patient in each group preservative was omitted from the collection pouch. Urinary oxalate was then measured enzymatically after removal of ascorbic acid with sodium nitrite. Preservatives proved necessary for full recovery of analyte. At doses of 500 mg. or more of ascorbic acid there was a statistically significant increase in urinary oxalate equivalent to 1.2 to 1.8% of the millimoles of ascorbate administered. This represented an increase in urinary oxalate excretion of 6 to 13 mg. per day per 1,000 mg. ascorbic acid supplement. This amount would increase the risk of calcium oxalate urolithiasis.

Topics: Adult; Ascorbic Acid; Calcium Oxalate; Dose-Response Relationship, Drug; Drug Overdose; Female; Humans; Kidney Calculi; Male; Middle Aged; Risk Factors

A 15-year-old girl presented after intentional ingestion of dapsone (7.2 g) and small quantities of azathioprine, methotrexate and prednisolone. The resulting methaemoglobinaemia and lactic acidosis persisted despite treatment with methylene blue, multiple-dose activated charcoal and ascorbic acid. Continuous veno-venous haemofiltration for 75 hours was used to treat the dapsone overdose. The patient's serum dapsone concentrations were measured during and after continuous veno-venous haemofiltration. The rate of elimination of dapsone was over three times higher during, compared to after, continuous veno-venous haemofiltration. Continuous renal replacement therapy successfully reduced toxic dapsone concentrations in this patient with a good outcome.

Topics: Acidosis, Lactic; Adolescent; Anti-Infective Agents; Antidotes; Antioxidants; Ascorbic Acid; Blood Gas Analysis; Charcoal; Dapsone; Drug Overdose; Female; Gastric Lavage; Hemofiltration; Humans; Methemoglobinemia; Renal Replacement Therapy; Respiration, Artificial

Although daily ingestion of high-dose vitamin C is generally regarded as largely innocuous, fatal nephrotoxicity can occur in some rare circumstances. We report a case where the patient, who chose to forgo any advanced conventional medical intervention (dialysis and mechanical ventilation), had failed to disclose his use of high-dose vitamin C and subsequently died. Intra-renal oxalate crystal deposition was demonstrated at autopsy. Directed enquiry with the family then revealed his high-dose vitamin C usage. Even though fully-informed discussion was limited by incomplete prospective disclosure, it remains the prerogative of any competent patient to decline any treatment, including those that may be considered life-saving.

Topics: Acute Kidney Injury; Aged; Ascorbic Acid; Blood Chemical Analysis; Critical Illness; Drug Overdose; Fatal Outcome; Humans; Male; Treatment Refusal; Vitamins

Topics: Adolescent; Ascorbic Acid; Coma; Drug Overdose; Emergency Service, Hospital; Hallucinogens; Humans; Hydrogen-Ion Concentration; Infusions, Intravenous; Male; N-Methyl-3,4-methylenedioxyamphetamine; Treatment Outcome

Topics: Ascorbic Acid; Drug Overdose; Humans; National Academies of Science, Engineering, and Medicine, U.S., Health and Medicine Division; Nutrition Policy; United States; Vitamin E

To determine the ability of the Hemoccult and Gastroccult tests (SmithKline Diagnostics) to detect blood in vitro in whole-bowel irrigation (WBI) solution.. One tablet of ferrous gluconate 324 mg, ferrous sulfate 325 mg, or ascorbic acid 500 mg; or one Materna prenatal vitamin tablet (Lederle Laboratories) was dissolved in 30 mL of Colyte. Colyte alone and each test solution were tested with Hemoccult and Gastroccult slides, then retested at pH values of 3 and 8. Fresh solutions were then spiked with blood and tested with Gastroccult slides. Materna and ascorbic acid solutions were spiked with blood, then tested with Hemoccult slides.. Positive results were difficult to detect on Gastroccult slides. Hemoccult slides were falsely positive for solutions containing only iron and falsely negative for blood-spiked samples containing ascorbic acid.. Both the Hemoccult and Gastroccult tests may be unreliable in detecting GI bleeding in cases of iron overdose treated with WBI.

Topics: Ascorbic Acid; Delayed-Action Preparations; Drug Overdose; False Negative Reactions; False Positive Reactions; Ferrous Compounds; Gastrointestinal Hemorrhage; Humans; Iron; Occult Blood