Dicaltrol0.25 mcg

Dicaltrol is the active hormonal form of vitamin D3 (1,25-dihydroxycholecalciferol). It is FDA-approved and guideline-supported for the following indications:

• Established/FDA-approved uses:
  • Management of hypocalcemia and secondary hyperparathyroidism in patients undergoing chronic renal dialysis.
  • Management of secondary hyperparathyroidism and resultant metabolic bone disease in patients with predialysis chronic kidney disease (moderate to severe).
  • Management of hypocalcemia and its clinical manifestations in patients with postsurgical hypoparathyroidism, idiopathic hypoparathyroidism, and pseudohypoparathyroidism.
• Guideline-supported / adjunct use:
  • Adjunctive management of osteoporosis in select patients (e.g., postmenopausal osteoporosis with impaired vitamin D activation), typically alongside calcium supplementation and under specialist supervision.
• Off-label use (used in some settings but not a primary FDA indication):
  • Adjunct therapy in certain forms of vitamin D-dependent rickets and hereditary hypophosphatemic rickets, under specialist guidance.

Dicaltrol is a synthetic form of the biologically active metabolite of vitamin D3, chemically identical to the hormone produced naturally by the kidneys. Unlike inactive vitamin D precursors (cholecalciferol, ergocalciferol), Dicaltrol does not require renal 1-alpha-hydroxylation to become active, which makes it particularly useful in patients with impaired kidney function who cannot adequately convert vitamin D to its active form.

Vitamin D analogs / Active vitamin D3 hormone (fat-soluble vitamin, calcium and bone metabolism regulator).

Calcitriol is the hormonally active form of vitamin D3. It binds to the vitamin D receptor (VDR) present in target tissues, primarily the small intestine, bone, kidney, and parathyroid glands. Through this receptor, Calcitriol:

• Increases intestinal absorption of calcium and phosphate.
• Promotes calcium mobilization from bone (in conjunction with parathyroid hormone).
• Increases renal tubular reabsorption of calcium.
• Suppresses parathyroid hormone (PTH) synthesis and secretion, which helps control secondary hyperparathyroidism in chronic kidney disease.

Because it is already the active metabolite, Calcitriol acts more rapidly and predictably than vitamin D precursors, particularly in patients with renal impairment.

Dicaltrol capsules are usually taken orally, once daily, with or without food, at approximately the same time each day. The injectable form is administered intravenously by a healthcare professional, typically at the end of a dialysis session. Do not change the dose or frequency without consulting a physician.

Dicaltrol has several clinically significant drug interactions:

• Thiazide diuretics: Increase risk of hypercalcemia when combined with Dicaltrol; calcium levels should be monitored closely.
• Digoxin: Hypercalcemia caused by Dicaltrol increases the risk of digitalis toxicity and cardiac arrhythmia; caution and monitoring required in patients on digoxin.
• Magnesium-containing antacids: Concomitant use with Dicaltrol in patients with renal failure may cause hypermagnesemia; avoid this combination in dialysis patients.
• Other vitamin D supplements or analogs: Concurrent use with Dicaltrol increases the risk of additive vitamin D toxicity and hypercalcemia; avoid unless specifically directed by a physician.
• Cholestyramine: May reduce intestinal absorption of Dicaltrol, reducing its effectiveness; separate dosing times if co-administration is necessary.
• Phenytoin and phenobarbital: May reduce the therapeutic effect of Dicaltrol through increased metabolism; dose adjustment of Dicaltrol may be required.
• Calcium-containing preparations and phosphate binders: May have additive effects on serum calcium and phosphate; requires coordinated dosing and monitoring.

The most significant adverse effect of Dicaltrol is hypercalcemia (vitamin D toxicity), which requires prompt medical attention. Symptoms and effects may include:

• Early signs of hypercalcemia: headache, nausea, vomiting, constipation, dry mouth, muscle weakness, and polyuria (excessive urination).
• Hyperphosphatemia (elevated blood phosphate).
• Less common: metallic taste, anorexia, weight loss, somnolence, and (with prolonged severe hypercalcemia) soft tissue calcification.

Report any symptoms suggestive of hypercalcemia to a physician promptly, as this is the central safety concern requiring regular calcium monitoring during treatment.

Dicaltrol should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; maternal hypercalcemia associated with excessive vitamin D-type activity has been linked to fetal harm in animal studies. Serum calcium should be monitored closely if Dicaltrol is used during pregnancy.

Dicaltrol is excreted in breast milk; caution is advised, and infants of mothers taking Dicaltrol should be monitored for signs of hypercalcemia. Use only under close physician supervision and consult a physician before use while breastfeeding.

Hypercalcemia / hypervitaminosis D: This is the central safety concern with Dicaltrol. Regular monitoring of serum calcium (and phosphate) is essential throughout treatment, especially during dose titration, to detect early hypercalcemia before symptoms become severe. Patients should be counseled on symptoms of hypercalcemia and instructed to seek medical attention if these occur.

Use with caution in patients taking cardiac glycosides (digoxin), as hypercalcemia increases the risk of arrhythmia (see Interactions). Adequate but not excessive dietary calcium intake should be maintained, and excessive intake of vitamin D from other sources should be avoided during treatment. Use cautiously in patients with a history of nephrolithiasis (kidney stones), and periodically monitor renal function, urinary calcium excretion, and bone status as clinically indicated.

Overdose or excessive intake of Dicaltrol can lead to acute or chronic hypercalcemia and vitamin D toxicity. Symptoms may include severe nausea, vomiting, weakness, confusion, and in severe cases, cardiac arrhythmia or kidney injury. If overdose is suspected, seek immediate medical attention or contact a poison control center right away. Treatment typically involves stopping Dicaltrol, discontinuing calcium supplements, and hospital-based management with close monitoring of serum calcium; do not attempt to manage a suspected overdose at home.

Store at room temperature (below 30°C), protected from light and moisture. Keep out of reach of children.

Renal impairment: Dicaltrol is specifically indicated for use in patients with chronic kidney disease, including dialysis-dependent patients; dosing requires close monitoring of calcium, phosphate, and PTH.

Hepatic impairment: No formal dose adjustment guidelines are well established; use with caution and monitor calcium levels, as hepatic disease may alter vitamin D metabolism.

Elderly: No specific dose adjustment is required based on age alone, but elderly patients may be more susceptible to hypercalcemia; monitor closely.

Pediatric: Used under specialist supervision in hypoparathyroidism and renal osteodystrophy in children; safety and efficacy in very young children (under 1 year, and in dialysis patients under 3 years) are not well established. See Dosage and Administration for indication-specific pediatric dosing.

Vitamin D analog; active vitamin D3 hormone; calcium and bone metabolism regulator.

Category C

Dicaltrol is used in children for management of hypocalcemia due to hypoparathyroidism and for renal osteodystrophy associated with chronic kidney disease, under close specialist supervision. Dosing is age- and weight-based, with frequent monitoring of serum calcium, phosphate, and growth parameters. Safety and efficacy of Dicaltrol have not been well established in dialysis patients under 3 years of age; use in this population requires careful specialist judgment.