Calventra M

Uses

Adult: One Calcium Carbonate 500 tablet or as directed by the physician. For the prevention of osteoporosis, 1-3 Calcium Carbonate 500 tablet is recommended generally as a dietary supplement . Doses for children is half of those for adults. A large dose should not be taken without physician\'s advice.

Adolescent: One to two Calcium Carbonate tablet daily.

Children: One Calcium Carbonate tablet daily.

Vitamin D is an ingredient found in a variety of supplements and vitamins.

Vitamin D is indicated for use in the treatment of hypoparathyroidism, refractory rickets (also known as vitamin D resistant rickets), and familial hypophosphatemia .

Zinc sulfate is a drug used to replenish low levels of zinc or prevent zinc deficiency, or to test for zinc deficiency.

This medication is a mineral used to treat or prevent low levels of zinc alone and together with oral rehydration therapy (ORT). It is also used as a topical astringent. Zinc Sulfate Injection, USP is indicated for use as a supplement to intravenous solutions given for TPN.

Calventra M is also used to associated treatment for these conditions: Acid Reflux, Acid indigestion, Bloating, Calcium Deficiency, Calcium Metabolism Disorders, Calcium and Vitamin D Deficiencies, Colic, Dyspepsia, Gastric Ulcer, Gastroesophageal Reflux, Heartburn, Hemorrhoids, Hot Flushes, Hyperacidity, Hyperphosphataemia, Hypovitaminosis D, Low Bone Density, Osteodystrophy, Osteomalacia, Osteoporosis, Postmenopausal Osteoporosis, Postoperative Gas, Proctitis, Vertebral Fractures, Calcium loss, Gastrointestinal ulceration, Dietary supplementationDeficiency, Vitamin DDry Eyes, Local itching, Localized pain, Localized swelling, Nutritional supplementation

How Calventra M works

Calcium carbonate is a basic inorganic salt that acts by neutralizing hydrochloric acid in gastric secretions. It also inhibits the action of pepsin by increasing the pH and via adsorption. Cytoprotective effects may occur through increases in bicarbonate ion (HCO₃^-) and prostaglandins. Neutralization of hydrochloric acid results in the formation of calcium chloride, carbon dioxide and water. Approximately 90% of calcium chloride is converted to insoluble calcium salts (e.g. calcium carbonate and calcium phosphate).

Most individuals naturally generate adequate amounts of vitamin D through ordinary dietary intake of vitamin D (in some foods like eggs, fish, and cheese) and natural photochemical conversion of the vitamin D3 precursor 7-dehydrocholesterol in the skin via exposure to sunlight.

Conversely, vitamin D deficiency can often occur from a combination of insufficient exposure to sunlight, inadequate dietary intake of vitamin D, genetic defects with endogenous vitamin D receptor, or even severe liver or kidney disease . Such deficiency is known for resulting in conditions like rickets or osteomalacia, all of which reflect inadequate mineralization of bone, enhanced compensatory skeletal demineralization, resultant decreased calcium ion blood concentrations, and increases in the production and secretion of parathyroid hormone . Increases in parathyroid hormone stimulates the mobilization of skeletal calcium and the renal excretion of phosphorus . This enhanced mobilization of skeletal calcium leads towards porotic bone conditions .

Ordinarily, while vitamin D3 is made naturally via photochemical processes in the skin, both itself and vitamin D2 can be found in various food and pharmaceutical sources as dietary supplements. The principal biological function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet . At the liver, vitamin D3 or D2 is hydroxylated to 25-hydroxyvitamin D and then finally to the primary active metabolite 1,25-dihydroxyvitamin D in the kidney via further hydroxylation . This final metabolite binds to endogenous vitamin d receptors, which results in a variety of regulatory roles - including maintaining calcium balance, the regulation of parathyroid hormone, the promotion of the renal reabsorption of calcium, increased intestinal absorption of calcium and phosphorus, and increased calcium and phosphorus mobilization of calcium and phosphorus from bone to plasma to maintain balanced levels of each in bone and the plasma .

Zinc inhibits cAMP-induced, chloride-dependent fluid secretion by inhibiting basolateral potassium (K) channels, in in-vitro studies with rat ileum. This study has also shown the specificity of Zn to cAMP-activated K channels, because zinc did not block the calcium (Ca)-mediated K channels. As this study was not performed in Zn-deficient animals, it provides evidence that Zn is probably effective in the absence of Zn deficiency. Zinc also improves the absorption of water and electrolytes, improves regeneration of the intestinal epithelium, increases the levels of brush border enzymes, and enhances the immune response, allowing for a better clearance of the pathogens.

Dosage

Calventra M dosage

Calcium Carbonate is always used orally and when used as an antacid the recommended doses for adults are equivalent to 540-2000 mg Calcium Carbonate per day, doses for children being half of those for adults. As a dietary supplement, such as for the prevention of osteoporosis, 1250-3750 mg Calcium Carbonate (500-1500 mg calcium) daily is recommended in general, but again this will need to be tailored to the individual patient depending on any specific disease such as Calcium deficiency, malabsorption or parathyroid function. In pregnancy and lactation therecommended daily dose of calcium is 1200-1500 mg. In chronic renal failure the doses used vary from 2.5 - 9.0 gm Calcium Carbonate per day and need to be adjusted according to the individual patient. To maximize effective phosphate binding in this context the Calcium Carbonate should be given with meals.

Side Effects

In rare cases, flatulence, diarrhoea or constipation.

Toxicity

The use of pharmacological or nutraceutical vitamin d and/or even excessive dietary intake of vitamin d is contraindicated in patients with hypercalcemia, malabsorption syndrome, abnormal sensitivity to the toxic effects of vitamin d, and hypervitaminosis D .

Hypersensitivity to vitamin d is one plausible etiologic factor in infants with idiopathic hypercalcemia - a case in which vitamin d use must be strictly restricted .

As vitamin d intake is available via fortified foods, dietary supplements, and clinical drug sources, serum concentrations and therapeutic dosages should be reviewed regularly and readjusted as soon as there is clinical improvement . Dosage levels are required to be individualized on an individual patient by patient basis as caution must be exercised to prevent the presence of too much vitamin d in the body and the various potentially serious toxic effects associated with such circumstances .

In particular, the range between therapeutic and toxic doses is quite narrow in vitamin d resistant rickets . When high therapeutic doses are used, progress should be followed with frequent blood calcium determinations .

When treating hypoparathyroidism, intravenous calcium, parathyroid hormone, and/or dihydrotachysterol may be required .

Maintenance of normal serum phosphorus levels by dietary phosphate restriction and/or administration of aluminum gels as intestinal phosphate binders in those patients with hyperphosphatemia as frequently seen in renal osteodystrophy is essential to prevent metastatic calcification .

Mineral oil interferes with the absorption of lipid-soluble vitamins, including vitamin d preparations .

The administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with vitamin d can result in hypercalcemia .

At this time, no long term animal studies have been performed to evaluate vitamin potential for carcinogens, mutagenesis, or fertility .

As various animal reproduction studies have demonstrated fetal abnormalities in several species associated with hypervitaminosis D, the use of vitamin d in excess of the recommended dietary allowance during normal pregnancy should be avoided . The safety in excess of 400 USP units of vitamin d daily during pregnancy has not been established . The abnormalities observed are similar to the supravalvular aortic stenosis syndrome described in infants that is characterized by supravalvular aortic stenosis, elfin facies, and mental retardation .

In a nursing mother given large doses of vitamin D, 25-hydroxycholecalciferol appeared in the milk and caused hypercalcemia in her child. Caution is subsequently required when contemplating the use of vitamin d in a nursing woman, and the necessity of monitoring infants' serum calcium concentration if vitamin d is administered to a breastfeeding woman .

Adverse reactions associated with the use of vitamin d are primarily linked to having hypervitaminosis D occurring [FDA Lanel]. In particular, hypervitaminosis D is characterized by effects specific effects on specific organ systems. At the renal system, hypervitaminosis D can cause impairment of renal function with polyuria, nocturne, polydipsia, hypercalciuria, reversible asotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or even irreversible renal insufficiency which may result in death . Elsewhere, hypervitaminosis D can also cause CNS mental retardation . At the level of soft tissues, it can widespread calcification of the soft tissues, including the heart, blood vessels, renal tubules, and lungs . In the skeletal system, bone demineralization (osteoporosis) in adults can occur while a decline in the average rate of linear growth and increased mineralization of bones, dwarfism, vague aches, stiffness, and weakness can occur in infants and children . Finally, hypervitaminosis D can also lead to nausea, anorexia, and constipation at the gastrointestinal level as well as mild acidosis, anemia, or weight loss via metabolic processes .

The LD(50) in animals is unknown .

Human : TDLo ( Oral) 45mg/kg/7D-C : Normocytic anemia, pulse rate increase without fall inBP Human: TDLo (oral) 106mg/kg : Hypermotylity, diarrhea Mouse ; LD50 Oral : 245mg/kg Mouse : LD50 : subcutaneous : 781mg/kg

Precaution

In the presence of mild hypercalciuria, excretion levels must be carefully monitored and where necessary the dose of calcium carbonate should be reduced or treatment should be stopped. Patients with a history of stone formation should also be recommended to increase their fluid intake. High dosage of vitamin D should be avoided during Calcium therapy unless specifically indicated.

Interaction

Oral calcium can reduce internal absorption of tetracycline and fluoride prepa-rations and an interval of at least 3 hours should therefore be allowed between ingestion of these medications. Vitamin D increases internal absorption of calcium. The intestinal uptake of calcium may be reduced by concomitant ingestion of certain foods (e.g. spinach, milk and milk products).

Volume of Distribution

Calcium is rapidly distributed taken up by skeletal tissues following absorption and distribution into extracellular fluids. Bone contains 99% of the body's calcium and the remaining 1% is approximately equally distributed between intracellular and extracellular fluids.

After absorption zinc is bound to protein metallothionein in the intestines. Zinc is widely distributed throughout the body. It is primarily stored in RBCs, WBCs, muscles, bones, Skin, Kidneys, Liver, Pancreas, retina, and prostate.

Elimination Route

Maximal absorption occurs at doses of 500 mg or less taken with food. Oral bioavailability depends on intestinal pH, the presence of food and dosage.

Vitamin D3 and D2 are readily absorbed from the small intestine (proximal or distal) .

Approximately 20 to 30% of dietary zinc is absorbed, primarily from the duodenum and ileum. The amount absorbed is dependent on the bioavailability from food. Zinc is the most bioavailable from red meat and oysters. Phytates may impair absorption by chelation and formation of insoluble complexes at an alkaline pH. After absorption, zinc is bound in the intestine to the protein metallothionein. Endogenous zinc can be reabsorbed in the ileum and colon, creating an enteropancreatic circulation of zinc.

Half Life

Although certain studies suggest the half-life of 1,25-hydroxyvitamin D3 may be approximately 15 hours, the half-life of 25-hydroxyvitamin D3 appears to have a half-life of about 15 days . Intriguingly however, the half-lives of any particular administration of vitamin d can vary and in general the half-lives of vitamin D2 metabolites have been demonstrated to be shorter overall than vitamin D3 half-lives with this being affected by vitamin d binding protein concentrations and genotype in particular individuals .

3 hours

Clearance

Some studies propose an estimated clearance rate for 1,25-dihydroxyvitamin D as 31 +/- 4 ml/min in healthy adults .

Elimination Route

Excreted mainly in the feces. The majority of renally filtered calcium is reabsorbed in the ascending limb of the loop of Henle and the proximal and distal convoluted tubules. Also secreted by sweat glands.

The primary excretion route of vitamin D is via the bile into the feces .

Primarily fecal (approximately 90%); to a lesser extent in the urine and in perspiration.

Pregnancy & Breastfeeding use

Pregnant women : Calcium containing drugs are used widely in pregnancy by way of calcium supplement or antacid therapy. No relationship between malformation in general and calcium exposure has been noted.

Lactating mother : There is no contraindication to the use of calcium carbonate in lactating mother.

Contraindication

Hypersensitivity to the Calcium Carbonate or any inactive ingredient of the medication. Hypercalcemia (e.g. in hyperparathyroidism, overdosage of vitamin D, demineralizing tumours such as plasmacytomas and bone metastases), severe hypercalcuria, several renal insufficiency.

Special Warning

USE IN CHILDREN: Calcium carbonate has been extensively studied in children and infants with chronic renal failure and is both safe and effective.

USE IN ELDERLY: In case of elderly patients with renal failure when calcium carbonate is taken constipation may be troublesome one for this group. For this reason, monitoring of serum calcium and phosphate is of course indicated for elderly patients.

Storage Condition

Store in a cool, dry place in controlled room temperature.

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