One Alpha Capsule

One Alpha Capsule 0.25 mcg is a synthetic vitamin D₃ analogue that plays an important role in calcium homeostasis and bone metabolism. It is converted in the liver to its active form, enabling it to regulate calcium and phosphate balance and support healthy bone mineralization. Compared with vitamin D, alfacalcidol has a prolonged pharmacological effect because its activation bypasses the kidney's regulated activation step. It is used to manage conditions associated with impaired vitamin D metabolism, including hypocalcemia, secondary hyperparathyroidism, renal osteodystrophy, and various forms of rickets and osteomalacia. One Alpha Capsule 0.25 mcg is available in both oral and intravenous formulations.

One Alpha Capsule 0.25 mcg is a vitamin D analogue used for the management of hypocalcemia, secondary hyperparathyroidism, and osteodystrophy in patients with chronic renal failure, as well as some types of rickets and osteomalacia.

One Alpha Capsule 0.25 mcg is indicated in adult patients with chronic renal failure for the management of hypocalcemia, secondary hyperparathyroidism, or osteodystrophy.

One Alpha Capsule 0.25 mcg is indicated in the management of nutritional and malabsorptive rickets and osteomalacia, vitamin D-dependent rickets and osteomalacia, and hypophosphataemic vitamin D resistant rickets and osteomalacia.

• Hypocalcemia
• Hypophosphatemic Rickets
• Hypovitaminosis D
• Nutritional Rickets
• Osteodystrophy
• Osteomalacia
• Secondary Hyperparathyroidism (SHPT)
• Hypophosphatemic osteomalacia

One Alpha Capsule 0.25 mcg 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.

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.

One Alpha Capsule 0.25 mcg is absorbed passively and almost completely in the small intestine.

The active metabolite of alfacalcidol, 1,25-dihydroxyvitamin D, is transported to tissues via globulin, a specific transport protein.

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

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.

One Alpha Capsule 0.25 mcg 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.

• Take with or without food. Food does not affect the bioavailability.

• 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.