Calvit A
Calvit A Uses, Dosage, Side Effects, Food Interaction and all others data.
Alfacalcidol is a precursor of the active calcitriol. It does not require renal hydroxylation but requires 25-hydroxylation in the liver for conversion to calcitriol.
Alfacalcidol works to increase serum levels of calcium by stimulating intestinal calcium absorption, reabsorption of calcium from bone, and possibly the renal reabsorption of calcium. It also modestly promotes intestinal phosphorus absorption. In patients with renal failure, alfacalcidol increased intestinal calcium and phosphorus absorption in a dose-related manner. This increase in calcium and phosphorus levels occurs within three days following drug administration: this effect was reversed within three days of drug discontinuation. In patients with chronic renal failure, serum calcium levels were elevated while parathyroid hormone and alkaline phosphatase levels returned to normal levels within five days following alfacalcidol administration. Since alfacalcidol suppresses parathyroid hormone, a reduction in parathyroid hormone levels is achieved more rapidly in patients on intermittent intravenous therapy, with significant reductions occurring within three months of therapy. In patients receiving daily oral therapy of alfacalcidol, the time it takes alfacalcidol to normalize plasma calcium levels may be up to several months, possibly reflecting calcium being utilized for bone mineralization. In patients with nutritional osteomalacia, alfacalcidol increased calcium absorption with six hours of oral administration and the effects peaked at 24 hours.
Calcium plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. The skeleton acts as a major mineral storage site for the element and releases Ca2+ ions into the bloodstream under controlled conditions. Circulating calcium is either in the free, ionized form or bound to blood proteins such as serum albumin. Although calcium flow to and from the bone is neutral, about 5 mmol is turned over a day. Bone serves as an important storage point for calcium, as it contains 99% of the total body calcium. Low calcium intake may also be a risk factor in the development of osteoporosis. The best-absorbed form of calcium from a pill is a calcium salt like carbonate or phosphate. Calcium gluconate and calcium lactate are absorbed well by pregnant women. Seniors absorb calcium lactate, gluconate and citrate better unless they take their calcium supplement with a full breakfast.
Calcium (Ca2+) plays a pivotal role in the physiology and biochemistry of organisms and the cell. It plays an important role in signal transduction pathways, where it acts as a second messenger, in neurotransmitter release from neurons, contraction of all muscle cell types, and fertilization. Many enzymes require calcium ions as a cofactor, those of the blood-clotting cascade being notable examples. Extracellular calcium is also important for maintaining the potential difference across excitable cell membranes, as well as proper bone formation.
Trade Name | Calvit A |
Generic | Calcium + Alfacalcidol |
Weight | 0.25mcg |
Type | Capsule |
Therapeutic Class | |
Manufacturer | Marc Laboratories |
Available Country | India |
Last Updated: | September 19, 2023 at 7:00 am |
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)
Calcium is a mineral found in over-the-counter supplements or prescription formulations used for the treatment of specific medical conditions related to calcium deficiency.
Calcium plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. It is vital in cell signaling, muscular contractions, bone health, and signalling cascades.
Calvit A is also used to associated treatment for these conditions: Hypocalcemia, Hypophosphatemic Rickets, Hypovitaminosis D, Nutritional Rickets, Osteodystrophy, Osteomalacia, Secondary Hyperparathyroidism (SHPT), Hypophosphatemic osteomalaciaCalcium Deficiency, Deficiency, Vitamin D, Osteodystrophy, Osteomalacia, Osteoporosis, Chronic Hypocalcemia, Chronic Hypocalcemia caused by anticonvulsant medications, Care of the Joint, Mineral supplementation, Nutritional supplementation
How Calvit A 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 plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. More than 500 human proteins are known to bind or transport calcium. The skeleton acts as a major mineral storage site for the element and releases Ca2+ ions into the bloodstream under controlled conditions. Circulating calcium is either in the free, ionized form or bound to blood proteins such as serum albumin. Parathyroid hormone (secreted from the parathyroid gland) regulates the resorption of Ca2+ from bone. Calcitonin stimulates incorporation of calcium in bone, although this process is largely independent of calcitonin. Although calcium flow to and from the bone is neutral, about 5 mmol is turned over a day. Bone serves as an important storage point for calcium, as it contains 99% of the total body calcium. Low calcium intake may also be a risk factor in the development of osteoporosis. The best-absorbed form of calcium from a pill is a calcium salt like carbonate or phosphate. Calcium gluconate and calcium lactate are absorbed well by pregnant women. Seniors absorb calcium lactate, gluconate and citrate better unless they take their calcium supplement with a full breakfast. The currently recommended calcium intake is 1,500 milligrams per day for women not taking estrogen and 800 milligrams per day for women on estrogen. There is close to 300 milligrams of calcium in one cup of fluid milk. Calcium carbonate is currently the best and least expensive form of calcium supplement available.
Dosage
Calvit A 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.
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.
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.
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.
Elimination Route
Alfacalcidol is absorbed passively and almost completely in the small intestine.
Half Life
The half-life of alfacalcidol ranges from three to four hours.
Elimination Route
The kidney excretes 250 mmol a day in urine, and resorbs 245 mmol, leading to a net loss in the urine of 5 mmol/d.
Pregnancy & Breastfeeding use
FDA has not yet classified the drug into a specified pregnancy category.
Contraindication
Hypercalcaemia, metastatic calcification, hyperphosphataemia (except when occurring with hypoparathyroidism), hypermagnesaemia.
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