Name: Calcium carbonate (TUMS, etc.)
Class: Element
Mechanism:
Absorption: Oral usu. ® 15-20% (up to 50% w/maximal stimulation). Depends of stomach acid for solubilization. \ Absorption is impaired in anchlorhydric or fasting patients. Absorption improved when taken w/food.
Dist.:
Metabolism.:
Excretion, t½:
Toxicity/S.E.s: Hypercalcemia, hypercalciuria. Drug interactions—¯ bioavailability and/or oral absorption of some drugs (e.g., etidronate, tetracyclines, iron salts, atenolol, norfloxacin). Thiazide diuretic-induced hypercalcemias exacerbated by calcium supplementation.
Utility: Treat mild hypocalcemia. Also maintenance after initial IV treatment. Provide 400-800 mg/d. Reduces/prevents bone loss in older women (800 mg/d).
Special Features: 40% calcium.