Home Drug Guide Doxercalciferol

Drug Guide

Generic Name

Doxercalciferol

Brand Names Hectorol

Classification

Therapeutic: Vitamin D analog for secondary hyperparathyroidism in CKD

Pharmacological: Vitamin D receptor agonist

FDA Approved Indications

  • Treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD) on dialysis

Mechanism of Action

Doxercalciferol activates vitamin D receptors, decreasing parathyroid hormone (PTH) synthesis and secretion, thereby reducing secondary hyperparathyroidism.

Dosage and Administration

Adult: Initial dose typically 1.5-3 mcg IV or orally once weekly, titrated based on PTH levels; dose adjustments every 4 weeks.

Pediatric: Limited data; use is off-label and based on clinical judgment.

Geriatric: No specific dosage adjustment; start at lower end of dosing range due to potential for increased sensitivity.

Renal Impairment: Use with caution; dose adjustments based on target PTH and calcium/phosphorus levels.

Hepatic Impairment: No specific adjustments required.

Pharmacokinetics

Absorption: Well absorbed orally; bioavailability approximately 70%.

Distribution: To body tissues, highly bound to serum proteins.

Metabolism: Primarily metabolized in the liver to inactive metabolites.

Excretion: Excreted mainly via the biliary route.

Half Life: Approximately 4-6 hours.

Contraindications

  • Hypercalcemia
  • Vitamin D toxicity

Precautions

  • Use with caution in patients with hyperphosphatemia, hepatic impairment, or known hypersensitivity. Adjust doses to avoid hypercalcemia and hyperphosphatemia; monitor serum calcium, phosphorus, and PTH levels regularly.

Adverse Reactions - Common

  • Hypercalcemia (Common)
  • Nausea (Less common)
  • Fatigue (Less common)

Adverse Reactions - Serious

  • Hypercalcemia leading to arrhythmias or vascular calcification (Serious, requires immediate attention)
  • Hyperphosphatemia (Serious, monitor closely)

Drug-Drug Interactions

  • Thiazide diuretics (may increase calcium levels)
  • Other vitamin D analogs (risk of toxicity)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor serum calcium, phosphorus, and PTH levels regularly. Assess for signs of hypercalcemia (nausea, vomiting, weakness).

Diagnoses:

  • Risk for imbalanced electrolyte levels related to vitamin D therapy.

Implementation: Administer as prescribed; ensure regular laboratory monitoring; educate patients about symptoms of hypercalcemia.

Evaluation: Adjust dosage based on laboratory results and clinical response.

Patient/Family Teaching

  • Report symptoms of hypercalcemia (e.g., nausea, vomiting, weakness).
  • Maintain hydration and adhere to follow-up appointments.
  • Avoid use of additional vitamin D or calcium supplements unless advised.

Special Considerations

Black Box Warnings:

  • None specified

Genetic Factors: None specific for doxercalciferol.

Lab Test Interference: May influence calcium, phosphorus, and PTH levels, potentially affecting other laboratory tests.

Overdose Management

Signs/Symptoms: Symptoms of hypercalcemia: nausea, vomiting, weakness, confusion, arrhythmias.

Treatment: Discontinue drug; provide hydration; administer bisphosphonates if severe; seek immediate medical attention.

Storage and Handling

Storage: Store at room temperature, 20-25°C (68-77°F).

Stability: Stable for the duration of the shelf life as provided by manufacturer.

This guide is for educational purposes only and is not intended for clinical use.