Details About Overdose or Poisoning Generic Salt :: Calcium
Drug Pharmacology ::
Calciumis a cation that is necessary for the normal functioning of a varietyof enzymes and organ systems, including muscle and nerve tissue.Hypocalcemia, or a blockade of calcium’s effects, may cause musclecramps, tetany, and ventricular fibrillation. Antagonism ofcalcium-dependent channels results in hypotension, bradycardia, andatrioventricular block.
Calcium ions rapidly bind to fluoride ions, abolishing their toxic effects.
Calciumcan reverse the negative inotropic effects of calcium antagonists;however, depressed automaticity and AV nodal conduction velocity andvasodilation may not respond to calcium administration.
Calcium stabilizes cardiac cell membranes in hyperkalemic states.
Drug Indications ::
Symptomatic hypocalcemia resulting from intoxication by fluoride, oxalate, or the intravenous anticoagulant citrate.
Hydrofluoric acid exposure (see Hydrogen Fluoride and Hydrofluoric Acid).
Hypotension in the setting of calcium channel antagonist (eg, verapamil) overdose (see Calcium Antagonists).
Severehyperkalemia with cardiac manifestations (relatively contraindicated inthe setting of digitalis toxicity; see III.B, below).
E. Symptomatic hypermagnesemia.
Drug Contra-Indications ::
Hypercalcemia except in the setting of calcium channel antagonist poisoning, where hypercalcemia may be desirable.
Although controversial, calcium is relatively contraindicated in the setting of intoxication with cardiac glycosides (may aggravate digitalis-induced ventricular tachydysrhythmias) and should be reserved for life-threatening situations.
Note: Calcium chloride salt should notbe used for intradermal, subcutaneous, or intra-arterial injectionbecause it is highly concentrated and may result in further tissuedamage.
Drug Adverse Effects ::
IV. Adverse effects
Tissue irritation, particularly with calcium chloride salt; extravasation may cause local irritation or necrosis.
Hypercalcemia, especially in patients with diminished renal function.
Hypotension, bradycardia, syncope, and cardiac dysrhythmias caused by rapid intravenous administration.
E. Constipation caused by orally administered calcium salts.
F. Use in pregnancy. FDAcategory C (indeterminate). This does not preclude its acute,short-term use for a seriously symptomatic patient (see Table III–1).
Drug Lab Interactions ::
Drug or laboratory interactions
Inotropicand dysrhythmogenic effects of digitalis may be potentiated by calcium.The use of intravenous calcium in the setting of cardiac glycosidetoxicity is not absolutely contraindicated, but indications remaincontroversial.
Aprecipitate will form with solutions containing soluble salts ofcarbonates, phosphates, or sulfates and with various antibiotics.
Drug Dose Management ::
Dosage and method of administration. Note: Calcium chloride contains nearly three times the amount of Ca2+per milliliter of 10% solution compared with the same concentration ofcalcium gluconate. A 10% solution of calcium chloride contains 27.2mg/mL of elemental calcium. A 10% solution of calcium gluconatecontains 9 mg/mL of elemental calcium.
Oral fluoride ingestion. Administer calcium-containing antacid (calcium carbonate) orally to complex fluoride ions.
Symptomatic hypocalcemia, hyperkalemia. Give10% calcium gluconate, 10–20 mL (children, 0.2–0.3 mL/kg), or 10%calcium chloride, 5–10 mL (children, 0.1–0.2 mL/kg), slowly IV. Repeatas needed every 5–10 minutes.
Calcium antagonist poisoning. Start with doses as described above. High-dose calciumtherapy has been reported to be effective in some cases of severecalcium channel blocker overdose. Corrected calcium concentrations ofapproximately 1.5 to 2 times normal have correlated with improvedcardiac function. In the setting of calcium channel antagonistoverdose, as much as 30 g of calcium gluconate has been given over 10hours, resulting in a serum calcium concentration of 23.8 mg/dL, whichwas tolerated without adverse effect. However, not all patients willtolerate extreme elevations in serum calcium concentrations. Administercalcium as multiple boluses (eg, 1 g every 10–20 minutes) or as acontinuous infusion (eg, 20–50 mg/kg/h). Serum calcium concentrationsshould be measured every 1–2 hours during therapy with high-dosecalcium.
Dermal hydrofluoric acid exposure. Forany exposure involving the hand or fingers, obtain immediateconsultation from an experienced hand surgeon or medical toxicologist.Regardless of the specific therapy chosen, systemic narcotic analgesicsshould be strongly considered strongly as adjunctive therapy.
1. Topical.Calcium concentrations for topical therapy have ranged from 2.5 to 33%;the optimal concentration has not been determined. Most commonly, a2.5% gel is prepared by combining 1 g of calcium gluconate per 40 g(approximately 40 mL) of water-soluble base material (Surgilube, K-YJelly). A 32.5% gel can be made by compounding a slurry of ten 650-mgcalcium carbonate tablets in 20 mL of water-soluble lubricant. Forexposures involving the hand or fingers, place the gel in a largesurgical latex glove to serve as an occlusive dressing to maximize skincontact. Topical calcium gluconate treatment is much more effective ifapplied within 3 hours of the injury.
2. For subcutaneous injection (when topical treatment fails to relieve pain), inject 5–10% calcium gluconate (not chloride) SC intralesionally and perifocally (0.5–1 mL/cm2of affected skin), using a 27-gauge or smaller needle. This can berepeated two to three times at 1- to 2-hour intervals if pain is notrelieved. No more than 0.5 mL should be injected into each digit.
3. Bier block technique:
Establish distal IV access in the affected extremity (eg, dorsum of the hand).
Exsanguinate the extremity by elevation for 5 minutes. Alternatively,an Esmarch bandage may be utilized by wrapping from the distal toproximal extremity.
Inflate a blood pressure cuff to just above systolic blood pressure. The arm can then be lowered or the bandage removed.
With the cuff kept inflated, infuse 25–50 mL of a 2% calcium gluconatesolution (10 mL of 10% calcium gluconate diluted with 40 mL of D5W) into the empty veins.
e. After 20–25 minutes, slowly release the cuff over 3–5 minutes.
f. Repeat if pain persists or use the intra-arterial infusion.
4. For intra-arterial administration, dilute 10 mL of 10% calcium gluconate with 50 mL of D5Wand infuse over 4 hours either through the brachial or the radialartery catheter. The patient should be monitored closely over the next4–6 hours, and if pain recurs, a second infusion should be given. Someauthors have reported 48–72 hours of continuous infusion.
E. Other sites of hydrofluoric acid exposure
1. Nebulized2.5% calcium gluconate has been reported for cases of inhalationalhydrofluoric acid exposure. Inhalational exposure should be consideredwith dermal exposures of > 5% total body surface area. Add 1.5 mL of10% calcium gluconate to 4.5 mL of sterile water to make a 2.5%solution.
2. Ocularadministration of 1% calcium gluconate solutions every 4–6 hours hasbeen utilized for 24–48 hours but is of unproven efficacy compared withirrigation with saline or water. Higher concentrations of calciumgluconate may worsen corrosive injury to ocular structures.Ophthalmology consultation should be obtained.
Drug Chemical Formulations ::
Oral. Calcium carbonate; suspension, tablets, or chewable tablets; 300–800 mg.
Parenteral. Calcium gluconate (10%), 10 mL (1 g contains 4.5 mEq calcium); calcium chloride (10%), 10 mL (1 g contains 13.6 mEq).
Topical. Calciumgluconate gel (2.5%) in 25-g and 30-g tubes but none of thesecommercially available formulations has been approved by the FDA.
The suggested minimum stocking levelto treat a 70-kg adult for the first 24 hours is 20–30 vials (1 g each)of 10% calcium gluconate and 10–15 vials (1 g each) of 10% calciumchloride.