Indications
PO, IV: Treatment and prevention of hypocalcemia.
PO: Adjunct in the prevention of postmenopausal osteoporosis.
IV: Emergency treatment of hyperkalemia
and hypermagnesemia and adjunct in cardiac arrest or
calcium channel blocking agent toxicity (calcium chloride,
calcium gluconate). Calcium carbonate: May be
used as an antacid. Calcium acetate: Control of hyperphosphatemia
in end-stage renal disease.
Action
Essential for nervous, muscular, and skeletal systems.
Maintain cell membrane and capillary permeability. Act
as an activator in the transmission of nerve impulses
and contraction of cardiac, skeletal, and smooth muscle.
Essential for bone formation and blood coagulation.
Binds to dietary phosphate to form an insoluble
calcium phosphate complex, which is excreted in the
feces, resulting in decreased serum phosphorus concentrations
(calcium acetate). Therapeutic Effects:
Replacement of calcium in deficiency states.
Control of hyperphosphatemia in end-stage renal disease
without promoting aluminum absorption (calcium
acetate).
Pharmacokinetics
Absorption: Absorption from the GI tract requires
vitamin D. IV administration results in complete bioavailability.
Distribution: Readily enters extracellular fluid.
Crosses the placenta and enters breast milk.
Metabolism and Excretion: Excreted mostly in
the feces; 20% eliminated by the kidneys.
Half-life: Unknown.
TIME/ACTION PROFILE (effects on serum
calcium)
ROUTE ONSET PEAK DURATION
PO unknown unknown unknown
IV immediate immediate 0.5–2 hr
Contraindications/Precautions
Contraindicated in: Hypercalcemia; Renal calculi;
Ventricular fibrillation; Concurrent use of calcium supplements
(calcium acetate).
Use Cautiously in: Patients receiving digitalis glycosides;
Severe respiratory insufficiency; Renal disease;
Cardiac disease; OB: Hypercalcemia mayqrisk of maternal
and fetal complications; Lactation: Breast feeding
not expected to harm infant provided that serum calcium
levels monitored.
Adverse Reactions/Side Effects
CNS: syncope (IV only), tingling. CV: CARDIAC ARREST
(IV only), arrhythmias, bradycardia. F and E: hypercalcemia.
GI: constipation, diarrhea (oral solution
only), nausea, vomiting. GU: calculi, hypercalciuria.
Local: phlebitis (IV only).
Interactions
Drug-Drug: Hypercalcemiaqthe risk of digoxin
toxicity. Chronic use with antacids in renal insufficiency
may lead to milk-alkali syndrome. Calcium
supplements, including calcium-containing antacids,
mayqrisk of hypercalcemia; avoid concurrent use. Ingestion
by mouthpthe absorption of orally administered
phenytoin and iron salts; take 1 hr before or 3
hr after oral calcium supplements. Excessive amounts
maypthe effects of calcium channel blockers. Calcium
acetate maypabsorption of orally administered
tetracyclines; take 1 hr before calcium acetate. Calcium
acetate maypabsorption of orally administered
fluoroquinolones; take 2 hr before or 6 hr after
calcium acetate. Calcium acetate maypabsorption of orally administered levothyroxine; take 4 hr before
or 4 hr after calcium acetate.pabsorption of etidronate
and risedronate (do not take within 2 hr of calcium
supplements). Concurrent use with diuretics
(thiazide) may result in hypercalcemia. Maypthe
ability of sodium polystyrene sulfonate to decrease
serum potassium.
Drug-Food: Cereals, spinach, or rhubarb mayp
the absorption of calcium supplements.
Route/Dosage
Doses are expressed in mg, g, or mEq of calcium.
PO (Adults): Prevention of hypocalcemia, treatment
of depletion, osteoporosis—1–2 g/day. Antacid—
0.5–1.5 g as needed (calcium carbonate
only). Hyperphosphatemia in end-stage renal disease
(calcium acetate only)—1334 mg with each meal,
mayqgradually (in absence of hypercalcemia) to
achieve target serum phosphate levels (usual dose
2001–2668 mg with each meal).
PO (Children): Supplementation—45–65 mg/kg/
day.
PO (Infants): Neonatal hypocalcemia—50–150
mg/kg (not to exceed 1 g).
IV (Adults): Emergency treatment of hypocalcemia,
cardiac standstill—7–14 mEq. Hypocalcemic tetany—
4.5–16 mEq; repeat until symptoms are controlled.
Hyperkalemia with cardiac toxicity—2.25–
14 mEq; may repeat in 1–2 min. Hypermagnesemia—
7 mEq.
IV (Children): Emergency treatment of hypocalcemia—
1–7 mEq. Hypocalcemic tetany—0.5–0.7
mEq/kg 3–4 times daily.
IV (Infants): Emergency treatment of hypocalcemia—
1 mEq. Hypocalcemic tetany—2.4 mEq/
kg/day in divided doses.
Availability (generic available)
Calcium Acetate
Gelcaps: 667 mg (169 mg elemental Ca). Tablets:
667 mg (169 mg elemental Ca). Oral solution: 667
mg (169 mg elemental Ca)/5 mL.
Calcium Carbonate
Tablets: 500 mg (200 mg Ca)OTC, 600 mg (240 mg
Ca)OTC, 650 mg (260 mg Ca)OTC, 667 mg (266.8 mg
Ca)OTC, 1 g (400 mg Ca)OTC, 1.25 g (500 mg Ca)OTC, 1.5
g (600 mg Ca)OTC. Chewable tablets: 350 mg (300
mg Ca)OTC, 420 mg (168 mg Ca)OTC, 450 mg OTC, 500
mg (200 mg Ca)OTC, 750 mg (300 mg Ca)OTC, 1 g (400
mg Ca)OTC, 1.25 g (500 mg Ca)OTC. Gum tablets: 300
mg OTC, 450 mg OTC, 500 mg (200 mg Ca)OTC. Capsules:
1.25 g (500 mg Ca)OTC. Lozenges: 600 mg (240 mg
Ca)OTC. Oral suspension: 1.25 g (500 mg Ca)/5
mLOTC. Powder: 6.5 g (2400 mg Ca)/packetOTC.
Calcium Chloride
Injection: 10% (1.36 mEq/mL).
Calcium Citrate
Tablets: 250 mgOTC.
Calcium Gluconate
Tablets: 500 mg (45 mg Ca)OTC, 650 mg (58.5 mg
Ca)OTC, 975 mg (87.75 mg Ca)OTC, 1 g (90 mg Ca)OTC.
Injection: 10% (0.45 mEq/mL).
Calcium Lactate
Tablets: 325 mg (42.45 mg Ca)OTC, 500 mg OTC, 650
mg (84.5 mg Ca)OTC.
Tricalcium Phosphate
Tablets: 600 mg (234 mg Ca)OTC.
No comments:
Post a Comment