Calcium carbonate

Calcium carbonate

[tablets 5 cents]

ADMINISTRATION ROUTES:

• PO

ALTERNATIVE NAMES:

• Calci-Tab, Caltrate, Calcium-Sandoz

ICU INDICATIONS:

1. calcium supplementation

PRESENTATION AND ADMINISTRATION:

• PO:
  Calci-Tab 500 (500mg elemental calcium), Calci-Tab 600 (600mg elemental calcium), Caltrate tablets (600mg elemental calcium), Calci-Tab Effervescent (1gm elemental calcium), Calcium Sandoz (5.23gm of calcium lactate-gluconate, 0.8gm of calcium carbonate)

DOSAGE:

• PO:
  500mg-1800mg of elemental calcium per day

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

• Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

• Not applicable

CLINICAL PHARMACOLOGY:

• Calcium.

CONTRAINDICATIONS:

1. Hypercalcaemia
2. Digitalis toxicity
3. hyperphosphataemia (do not administer calcium if the Calcium + Phosphate is >5.5; this is an indication for dialysis)

WARNINGS

• Nil

PRECAUTIONS

• General:
  Elderly, fluid restriction, decreased GI motility, GI obstruction, dehydration.
• Laboratory Tests:
  No tests in addition to standard ICU tests are required.
• Drug/Laboratory Test Interactions:
  False Increase: Chloride, benzodiazepine (false positive). False Decrease: Magnesium, lipase.

IMPORTANT DRUG INTERACTIONS FOR THE ICU

• Calcium channel blockers:
  Calcium administration may inhibit calcium channel blocker activity.
• Doxycycline, tetracycline:
  Co-therapy with a tetracycline and calcium carbonate can reduce the serum concentrations and efficacy of tetracyclines.
• Quinolones:
  Reduced bioavailability of quinolone antibiotics.
• Thiazides:
  Large doses of calcium with thiazides may lead to milk-alkali syndrome.

ADVERSE REACTIONS

• Cardiovascular:
  Bradycardia, cardiac arrest, dysrhythmias, heart block, hemorrhage, hypotension, rebound hypertension, shortened QT interval.
• Gastrointestinal:
  Anorexia, constipation, diarrhoea, flatulence, nausea, obstruction, rebound hyperacidity, vomiting.
• Genitourinary:
  Renal dysfunction, renal failure, renal stones.
• Metabolic:
  Hypercalcaemia (drowsiness, lethargy, muscle weakness, headache, constipation, coma, anorexia, nausea, vomiting, polyuria, thirst); metabolic alkalosis; milk-alkali syndrome (nausea, vomiting, disorientation, headache).