Bigalfa

Uses

Alfacalcidol is used for:

• It is used to increase the amount of vitamin D in your body. This often increases calcium levels as well which can help in treatment of certain illnesses.
• In general this drug is used to treat diseases where the amount of calcium and phosphate (which is controlled by the level of vitamin D) in your body needs changing.
• Benefits of being on this drug can include control of the levels of calcium and phosphate in your body.
• Treat and prevent bone conditions that are caused by kidney failure (osteodystrophy)
• Treat illnesses and abnormalities affecting the parathyroid glands which make a substance called the parathyroid hormone.
• Correct low levels of calcium in the blood of newborn babies (hypocalcaemia)
• Treat the softening and deformity of the bones due to lack of calcium (rickets or osteomalacia)

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.

Bigalfa is also used to associated treatment for these conditions: Hypocalcemia, Hypophosphatemic Rickets, Hypovitaminosis D, Nutritional Rickets, Osteodystrophy, Osteomalacia, Secondary Hyperparathyroidism (SHPT), Hypophosphatemic osteomalaciaAcid 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 supplementation

How Bigalfa works

In conditions like chronic renal failure, renal bone disease, hypoparathyroidism, and vitamin D dependent rickets, the kidneys' capacity for 1α-hydroxylation is impaired, leading to reduced production of endogenous 1,25-dihydroxyvitamin D and aberrated mineral metabolism. As an active and potent analog of vitamin D, alfacalcidol works to restore the functions and activities of endogenous 1,25-dihydroxyvitamin D.

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).

Dosage

Bigalfa dosage

Adults: The usual starting dose is 1 microgram each day. People usually take between 1 and 3 micrograms each day. Most people take between 0.25 and 1 microgram each day once the blood test results show the medicine is working.

If you have very low levels of calcium in your blood, your doctor may prescribe between 3 and 5 microgram each day. Your doctor may prescribe another medicine called a calcium supplement to take as well as Alfacalcidol. This will help to keep the right amount of calcium level in your blood.

Elderly: The usual starting dose is 0.5 microgram each day.

Children:

• Newborn and premature babies: The usual starting dose is 0.05 to 0.1 microgram per kilogram of body weight each day. If the level of calcium in their blood is very low, up to 2 micrograms per kilogram of body weight may be needed each day. A dose of 0.1 microgram per kilogram body weight each day is used to stop low blood calcium levels in premature babies.
• Children weighing less than 20 kilograms: The usual starting dose is 0.05 microgram per kilogram body weight each day.
• Children weighing more than 20 kilograms: The usual starting dose is 1 microgram each day.

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

Anorexia, nausea, vomiting, diarrhoea, lassitude, polyuria, sweating, headache, thirst, vertigo, pruritus, rash, urticaria. Hypercalcaemia, hypercalciuria and ectopic calcification.

In case of renal impairment, hyperphosphataemia. In hypercalcaemic dialysis patients, possibility of calcium influx from the dialysate should be considered.

In rare cases, flatulence, diarrhoea or constipation.

Toxicity

There is a discrepancy across a number of reported LD₅₀ values for alfacalcidol, which can be attributed to differences in the procedures used in laboratories. Oral LD₅₀ in mice ranges from 440 to 490 mcg/kg. Intravenous in mice was 290 mcg/kg; however, another source presented 56 mcg/kg in female mice and 71 mcg/kg in male mice. Oral LD₅₀ in rats ranges from 340 to 720 mcg/kg.

In case of an acute accidental overdose following oral administration, emesis or gastric lavage can be induced to prevent further drug absorption. Mineral oil may be used to promote fecal drug elimination in instances where the drug was already absorbed in the stomach.

Alfacalcidol overdose can lead to hypercalcemia, hypercalciuria, and hyperphosphatemia. Similarly, a high intake of calcium and phosphate concurrently with a therapeutic dose of alfacalcidol can result in those conditions. Hypercalcemia most commonly presents with headache, weakness, hypertension, somnolence, dizziness, sweating, anorexia, nausea, vomiting, diarrhea, constipation, polyuria, polydipsia and muscle and bone pain, and metallic taste. Hypercalcemia should be responded to with discontinuation of alfacalcidol, a low calcium diet and withdrawal of calcium supplements. Prolonged hypercalcemia can lead to nephrocalcinosis, nephrolithiasis, and reduced kidney function. In cases of severe hypercalcemia, general supportive measures are recommended, which may include forced diuresis and close monitoring of renal function, electrolytes, and electrocardiographs. Monitoring for abnormalities is especially critical in patients receiving digitalis glycosides. Management with glucocorticosteroids, loop diuretics, bisphosphonates, and calcitonin, as well as hemodialysis with low calcium content, may be considered.

Precaution

Pregnancy, lactation, renal impairment, infants, elderly. Monitor serum levels of calcium in patients with renal failure. Caution in hypercalciuria in those with history of renal calculi. Avoid in patients with hypersensitivity to inj. containing propylene glycol.

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

Thiazides may increase the risk of hypercalcaemia. Some antiepileptics e.g. carbamazepine, phenobarbital, phenytoin and primidone may increase vitamin D requirements. Rifampicin, isoniazid and corticosteroids may reduce the efficacy of vitamin D.

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.

Elimination Route

Alfacalcidol is absorbed passively and almost completely in the small intestine.

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.

Half Life

The half-life of alfacalcidol ranges from three to four hours.

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.

Pregnancy & Breastfeeding use

FDA has not yet classified the drug into a specified pregnancy category.

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

Hypercalcaemia, metastatic calcification, hyperphosphataemia (except when occurring with hypoparathyroidism), hypermagnesaemia.

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.

Innovators Monograph

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