In iron poisoning

E. Activated charcoal is highly effective in iron poisoning. 

Answer D. Deferoxamine chelates iron and is the antidote in iron poisoning. Gastric lavage should be attempted with care regarding aspiration, but changes in urine pH have no effect on the elimination of iron. laboratory results will reveal an increased anion gap indicative of acidosis. The systemic absorption of many drugs taken orally can be reduced by activated charcoal unfortunately, iron is not one of them. 

Interesting chemotherapeutic possibilities are suggested by this knowledge that the iron-foraging of bacteria is very different from that of mammals. For information on the use of siderochromes as antidotes in iron poisoning, see Section 11.6. 

Adamson lYR, Sienko A, Tenenbein M (1993) Pulmonary toxicity of deferoxamine in iron-poisoned mice. Toxicol Appl Pharmacol 120 13-19 Aisen P (1992) Entry of iron into cells a new role for the transferrin receptor in modulating iron release from transferrin. Ann Neurol 32 S62-S68 Aksoy M, Birdwood GFB (eds) (1985) Hypertransfusion and iron chelation in thalassemia. Huber, Berne... 

Lovejoy FH Jr (1982) Chelation therapy in iron poisoning. J Toxicol Clin Toxicol... 

Most iron salts and compounds may be safely handled following common safe laboratory practices. Some compounds are irritants. A more serious threat is ingestion of massive quantities of iron salts which results in diarrhea, hemorrhage, fiver damage, heart damage, and shock. A lethal dose is 200 250 mg/kg of body weight. The majority of the victims of iron poisoning are children under five years of age. 

Siderophores like desferrioxamine may, therefore, find increasing applications not only in the treatment of iron poisoning and iron-overloaded disease states but also as chemotherapeutic agents, although the possible problems noted above cannot be ignored. 

The major adverse effect of warfarin is bleeding. (Ironically, this compound was originally introduced as a very effective ro-denticide. As the active ingredient in rodent poison, it causes death due to internal hemorrhaging.) Furthermore, because it readily crosses the placenta and can cause a hemorrhagic disorder in the fetus, it is contraindicated in pregnant women. 

Domoic acid (Fig. 28,80) (263) is a neuro-phycotoxin responsible for the mortality of wildlife and for amnesic shellfish poisoning (ASP) of humans during algal bloom. Domoic acid was first isolated from the red alga Chondria armata ( domoi in Japanese), and it is produced also by diatoms, such as Pseudo-nitzschia spp. For the latter, evidence has been presented that it is involved in iron acquisition (307). 

Iron is an essential element, for humans and for many forms of life, but even a modest excess can be toxic as the human body does not have an effective iron excretion mechanism. It is therefore necessary to maintain an appropriate level of iron in the body, to supply iron in absorbable form if it is deficient (anemia) and to remove iron if present in excess. Inorganic coordination chemistry plays an important role in dealing with these complementary conditions of deficiency and of excess. The latter condition is much more common than often supposed, for there are a number of conditions, such as hemochromatosis and thallasemia, where the build-up of iron in essential organs is eventually lethal. Mild iron poisoning is not infrequent in children, while even iron fortification of foodstuffs can have adverse effects. Mild iron poisoning can be treated with bicarbonate or phosphate, which presumably complex and precipitate the iron. ... 

It is indicated in metallic intoxication due to arsenic, mercury, gold, bismuth, lead, nickel, thallium and antimony in conjunction with sodium calcium edetate for lead poisoning. It is also useful in hepatolenticular degeneration (Wilson s disease). It is contraindicated in iron and cadmium poisoning. 

When injected, it forms a stable water-soluble iron complex (ferrioxamine) that prevents the iron from entering into further chemical reactions and is readily excreted in the urine giving the urine a characteristic reddish colour. Some of it is also excreted in the faeces via the bile. It can also chelate aluminium and thus is useful in aluminium overload. It is primarily a chelator used in acute iron poisoning and chronic iron overload as in thalassemia patients needing multiple transfusions. 

It is primarily indicated in lead poisoning. It is also useful in iron, zinc, copper, manganese and radioactive metal but not mercury poisoning. 

It is an orally active iron chelator. It is useful in acute iron poisoning, iron overload in cirrhosis, transfusion siderosis in thalassemia patients. Adverse effects are anorexia, vomiting, altered taste, joint pain and neutropenia. 

Exactly the opposite problem may occur for plants whose roots are growing in anaerobic media. In Hooded soils the roots may be exposed to high levels of irontll). posing potential problems of iron toxicity. Rice plants and water lilies with roots in anaerobic soils transport dioxygen (from the air or photosynthesis, or both) to the periphery of the roots where it oxidizes the iron(II) to irondll). In (his case the insolubility of Irondll) hydroxide is utilized to protect the plant from iron poisoning.113 A similar problem from too much iron occurs in parts of sub-Saharan Africa. 

Colloidal saccharated iron is sometimes used in place of ferric hydroxide as an antidote in arsenical poisoning, but its adsorptive capacity depends on the alkalinity of the medium.4 Thus a commercial preparation containing 0-75 per cent, of sodium hydroxide was found to adsorb 12-57 per cent, of arsenious oxide (reckoned on the amount of iron present) addition of alkali increased the adsorption until, with 1-28 per cent, of sodium hydroxide present, there was a maximum adsorption of 27 per cent. The addition of acid correspondingly diminished the adsorption. A gel of ferric magnesium hydroxide, if prepared without boiling, also adsorbs arsenic from sodium arsenite solutions.5... 

The stability constants of the FeIU siderophore complexes are some of the largest known, e.g. the ferrichrome and ferrioxamine E complexes have log values of the order 29 and 32 respectively as compared to a value of 25 for Fe(edta). So strong are these complexes that microbes have been observed to leach iron from stainless steel vessels. Not surprisingly the siderophores also find use in treating cases of iron poisoning and for the elimination of iron from cases of thalassaemia.84 Complexation of Fe11 is considerably weaker than that of FeIU and this is probably utilized for the release of the iron within the cells. 

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