From Big Medical Encyclopedia

TETACINUM-CALCIUM (Tetacinum-calcium; synonym: Natrii calcii ecletas, Sodium calcium edetate, Chelaton, EDTA, Edatacal etc.) — complexing means. Calcium-disodium salt ethylene diamine tetraacetic to - you; With 10 H 12 Ca 2 N 2 O 8 • 2Na + • 7H 2 O:

White crystal powder, inodorous. Let's easily dissolve in water, the pier is insoluble in organic solvents. weight (weight) 500,4. It is steady at storage.

T. - to. has ability to form low-toxic water-soluble complexes (chelates) with bivalent metals, to-rye interact with T. - to. by substitution of atom of calcium in its molecule. Complexes with T. - to. form only those metals, to-rye have affinity, bigger in comparison with calcium, to ethylene diamine tetraacetic to - those. Zinc, cadmium, cobalt, manganese, lead, mercury, uranium, yttrium, cerium and vanadium are among such metals. Antidotal efficiency of T. - to. depends not only on the size of a constant of stability of the chelates which are formed at interaction of T. - to. with the specified metals, but also from ability of drug to get to places of fixing of metals in an organism, durability of their linkng with biological substrates, etc.

it is Badly soaked up from went. - kish. a path (from 80 to 95% of the entered dose of drug are allocated with a stake during 24 hours). After intravenous administration of T. - to. collects preferential in extracellular liquid. Through a blood-brain barrier it gets badly and therefore in cerebrospinal liquid it is found in insignificant quantities. The period of its semi-removal makes apprx. 1 hour. During 24 hours with urine the St. 95% of the dose entered intravenously are removed.

T. - to. apply for treatment acute and hron. lead poisoning, cadmium, zinc, nickel, cobalt, vanadium, mercury, uranium, yttrium, cerium and including their radioisotopes. Appoint drug intravenously and inside. The adult intravenously (kapelno) enter on 10-— 20 ml 10% of solution into 250 — 500 ml of isotonic solution of sodium of chloride or 5% of solution of glucose 2 times a day with an interval between injections not less than 3 hours. Enter daily within 3 — 4 days with breaks on 3 — 4 days. Course of treatment of 1 month. At the encephalopathy which developed owing to intoxication lead in order to avoid increase in intracranial pressure of T. - to. it is reasonable to enter intramusculary on 5 — 10 ml 10% of solution of 4 — 6 times a day together with solution of novocaine.

At hron. intoxications lead and other ugy heavy metals T. - to. it is possible to appoint inside 0,5 g 4 times a day or on 0,25 g of 8 times a day. Drug is accepted every 1 — 2 day within 20 — 30 days. The course dose shall not exceed 30 g. For increase in efficiency of T. - to. it is possible to apply together with Unithiolum (see) or dpmerkaptopropranoly.

At acute food intoxications metals T. - to. it is possible to appoint inside only after careful clarification went. - kish. a path by means of a gastric lavage and a siphon enema since otherwise the complexes of metals which are formed with drug can be soaked up from went. - kish. a path and thereof to cause strengthening of intoxication.

Side effect T. - to. it can be shown by fervescence, the followed weakness, a fever and thirst. The headache, mial-giya, nausea, vomiting, anorexia, hypostasis and swelling of a mucous membrane of a nose, dacryagogue are sometimes observed. Against the background of use of T. - to. anemia and dermatitis can also develop. At intravenous administration of T. - to. in some cases causes thrombophlebitises in this connection it is not recommended to enter into a vein its solutions in concentration of St. 0,5%. At use in high doses of T. - to. there can be dystrophy of an epithelium of proximal renal tubules that, apparently, is caused not only by direct toxic effect of drug, but also simultaneous toxic influence of the complexes of metals removed by kidneys. Strengthening of symptoms of intoxication metals and damages of kidneys at elimination of radioisotopes against the background of use of T. - to. it is caused by mobilization of the last of fabric depots under the influence of drug. For prevention of nek-ry by-effects against the background of use of T. - to. appoint rat anti-acrodynia factors and B12, iron preparations. At emergence of allergic reactions use antihistaminic means.

Drug it is contraindicated at diseases of kidneys (nephrite, a nephrosis) p diseases of a liver with disturbance of its functions.

Forms of release: ampoules on 20 ml of 10% of solution; tablets on 0,5 g. Store in the place protected from light.

See also Complex connections , Complexons .

Bibliography: Umland F., etc. Complex connections in analytical chemistry, the lane with it., M., 1975; Chelating agents and metal chelates, ed. by F. P. Dwyer a. D. P. Mellor, N. Y. — L., 1964; D r e i s-b a with h R. H. Handbook of poisoning, Los Altos, 1980; The pharmacological basis of therapeutics, ed. by A. G. Gilman a. o., N. Y., 1980.

F. P. Trinus.