Products
Calcium is commercially available in numerous drug products as a monopreparation, a fixed combination with vitamin D (usually cholecalciferol), and other vitamins and minerals. The most commonly used dosage forms include chewable, lozenge, meltable and effervescent tablets. Film-coated tablets that can be swallowed whole have also been available for some time.
Structure and properties
Calcium (Ca) is a chemical element with atomic number 20 that belongs to the alkaline earth metals. It exists elementally as a gray to silvery metal. The melting point is 842 °C. Calcium occurs very frequently in nature, for example in the form of calcium carbonate, which is contained in limestone. Calcium sulfate (gypsum) is also a natural compound. Calcium has two valence electrons, which it readily gives off as a reactive element and forms salts. Like sodium, it reacts exothermically with water, resulting in the release of combustible hydrogen:
- Ca: (calcium elemental) + 2 H2O (water) Ca(OH)2 (calcium hydroxide) + H2 (hydrogen)
Calcium is present in drugs in the form of various salts. These include, for example, calcium carbonate, calcium glubionate, calcium hydrogen phosphate, calcium gluconate, calcium citrate and calcium lactate. The commonly used calcium carbonate (CaCO3, Mr = 100.1 g/mol) exists as a white powder that is practically insoluble in water.
Effects
Calcium (ATC A12AA) is taken to provide an adequate supply to the body. Calcium is one of the most important minerals and is important for the structure of bones and teeth, for the conduction of nerve cells, muscles, the heart and blood clotting, among other things.
Indications
- Prevention and treatment of calcium deficiency.
- Increased calcium requirement.
- For the prevention and treatment of osteoporosis.
- As an additional treatment for vitamin D deficiency.
- As an additional treatment for allergic diseases.
- Latent tetany (parenteral administration).
- As phosphate binders (calcium acetate and calcium carbonate), see under phosphate binders.
- Other areas of application.
Dosage
According to the professional information. The usual dose for adults is 500 to 1200 mg per day. The drugs are administered independently of meals.
Contraindications
- Hypersensitivity
- Hypercalcemia
- Calcium containing kidney stones
- Nephrocalcinosis
- Severe hypercalciuria
- Severe renal insufficiency
Full precautions can be found in the drug label.
Interactions
Calcium may reduce the absorption of other drugs into the body when given concomitantly. Medications affected include, for example, antibiotics such as tetracyclines and quinolones, iron tablets, levothyroxine, antiepileptic drugs, and the biphosphonates that are often combined with calcium. Adequate spacing of 2 to 3 hours is recommended when taking them. Other drug interactions are possible with cardiac glycosides, glucocorticoids, antacids, phosphates, and thiazides. Vitamin D increases the absorption of calcium, which is usually desirable.
Adverse effects
Possible adverse effects include digestive symptoms such as flatulence, constipation, and diarrhea. Rarely, hypercalcemia and kidney stone formation are possible. Other rare adverse effects such as increased risk of cardiovascular disease are discussed.
