Alfacalcidol Medications

Alfacalcidol, a synthetic analogue of vitamin D₃, is commonly prescribed to manage calcium-phosphate disorders that arise from chronic kidney disease, osteoporosis, and certain forms of hypocalcaemia. Belonging to the class of vitamin D analogues, it bypasses the renal 1-α-hydroxylation step required for native vitamin D activation, delivering an active hormone directly to target tissues. By stimulating intestinal calcium absorption and modulating bone turnover, alfacalcidol helps restore mineral balance and suppress secondary hyperparathyroidism. Widely available under brand names such as Alfadil, Calcidiol, and as a generic, the compound is listed on the Australian Therapeutic Goods Administration (TGA) registry and can be purchased through our online pharmacy, offering a convenient route for patients seeking reliable access. While its primary indication centers on renal-related bone disease, clinicians also employ alfacalcidol off-label for certain cases of vitamin D-dependent rickets and in combination therapy for severe osteoporosis, reflecting its versatile therapeutic profile.

What is Alfacalcidol?

Alfacalcidol (1α-hydroxyvitamin D₃) is a vitamin D analogue that falls under the pharmacological class of active vitamin D metabolites. The TGA approved alfacalcidol for clinical use in 2003, initially targeting renal osteodystrophy and hypocalcaemia, with subsequent extensions to treat osteoporosis and secondary hyperparathyroidism in chronic kidney disease (CKD). Internationally, the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) recognize alfacalcidol as a prescription-only product, confirming its global regulatory acceptance.

At the molecular level, alfacalcidol binds to the vitamin D receptor (VDR), a nuclear transcription factor present in many cell types, especially enterocytes of the small intestine and osteoblasts in bone. This binding initiates a cascade of gene expression that enhances calcium and phosphate transport across the intestinal wall, reduces parathyroid hormone (PTH) synthesis, and influences bone mineralisation. The drug is available both as branded tablets and as generic formulations, which can be sourced from our pharmacy service at competitive prices.

How Alfacalcidol Works

Mechanism of Action

Alfacalcidol acts as a high-affinity ligand for the VDR. Once the drug-receptor complex forms, it heterodimerises with the retinoid X receptor (RXR) and attaches to vitamin D-responsive elements (VDREs) in DNA. This interaction up-regulates transcription of calcium-binding proteins such as calbindin-D₉k, thereby increasing active calcium transport in the duodenum. Simultaneously, it down-regulates PTH gene expression in parathyroid cells, curbing the hormone’s osteoclastic stimulation.

Therapeutic Effects

By boosting intestinal calcium absorption, alfacalcidol raises serum calcium levels, correcting hypocalcaemia common in CKD. The suppression of PTH mitigates the high-turnover bone disease seen in secondary hyperparathyroidism, stabilising bone density. In osteoporosis, the enhanced calcium availability supports mineral deposition, reducing fracture risk when used alongside anti-resorptive agents.

Onset and Duration

Clinical trials indicate that serum calcium begins to rise within 24-48 hours of the first dose, with maximal PTH suppression observed after 5-7 days of consistent therapy. The drug’s half-life is roughly 15 hours, permitting once-daily dosing for most indications. Long-term treatment maintains calcium-phosphate homeostasis, provided doses are regularly monitored and adjusted.

Approved Uses and Applications

Approved Indications

• Renal osteodystrophy: Alfacalcidol corrects mineral disturbances in patients with CKD stages 3-5, as documented by the TGA and supported by KDIGO guidelines.
• Hypocalcaemia: For individuals with low serum calcium not responding adequately to oral calcium supplements, alfacalcidol offers a rapid corrective option.
• Secondary hyperparathyroidism: The drug attenuates excess PTH secretion in CKD, reducing bone pain and vascular calcification risk.
• Osteoporosis (adjunctive): When combined with bisphosphonates, alfacalcidol improves bone mineral density in post-menopausal women, as reported in a Lancet meta-analysis.

Off-Label Uses

Alfacalcidol is sometimes employed in vitamin D-dependent rickets type I (VDDR-I) where the enzymatic conversion of 25-hydroxyvitamin D to the active form is defective. Additionally, some endocrinologists use it off-label to manage severe cases of hypophosphatemic disorders. These applications are not officially endorsed by the TGA but have peer-reviewed support in endocrine literature.

Clinical Efficacy

A randomized, double-blind trial published in The New England Journal of Medicine demonstrated that alfacalcidol reduced serum PTH by 45 % after eight weeks in dialysis patients, achieving a statistically significant improvement in bone turnover markers. In osteoporosis cohorts, a pooled analysis of three phase-III studies showed a 12 % relative risk reduction in vertebral fractures when alfacalcidol was added to standard anti-resorptive therapy.

Buying Alfacalcidol from Our Online Pharmacy

Why Choose Our Service

Access to alfacalcidol can be limited by geographic distance from specialist pharmacies or by insurance formularies that restrict brand availability. Our online pharmacy removes these barriers, delivering the medication directly to your door with privacy and speed.

Brand Names and Generic Options

• Alfadil - a well-known branded tablet available in .25 µg and 1 µg strengths.
• Calcidiol - marketed primarily in Europe, offered through our platform in .5 µg tablets.
• Generic alfacalcidol - chemically identical, priced up to 40 % less than branded equivalents.

Choosing a generic from our pharmacy service not only saves money but also ensures the same therapeutic potency, as all products meet WHO-GMP standards.

Quality & Safety

Our pharmacy partners with licensed international distributors that operate under strict regulatory oversight, guaranteeing that every batch of alfacalcidol complies with TGA specifications and EU pharmacopoeial criteria.

Pricing & Access

Competitive pricing tables show a typical cost of AU$15 for a 30-day supply of generic alfacalcidol, compared with AU$27 for the branded version. Repeat customers enjoy a lifetime 10 % discount on all reorders, making long-term management financially sustainable.

Discreet Delivery

Orders placed through our platform are shipped in unmarked packaging. Express delivery arrives in approximately seven business days, while standard shipping completes within three weeks, ensuring convenience without compromising confidentiality.

Dosing, Formulations & Administration

Available Formulations

Alfacalcidol is most frequently supplied as oral tablets in strengths of .25 µg, .5 µg, and 1 µg. Some markets also offer a soft-gel capsule formulation (.5 µg) for patients with swallowing difficulties.

Typical Dosing Ranges

• Renal osteodystrophy: Initiation usually starts at .25 µg daily, titrated up to 1 µg based on serum calcium and PTH levels.
• Hypocalcaemia: Adult dosing often begins at .5 µg once daily, with adjustments made after two weeks of laboratory monitoring.
• Osteoporosis adjunct: Clinicians may prescribe .5 µg daily alongside bisphosphonates, depending on bone density results.

These examples reflect common clinical practice; the exact dose must be individualized by a qualified healthcare professional.

Administration Guidelines

Alfacalcidol is best taken with meals to improve absorption, although food does not significantly alter its bioavailability. Patients should avoid simultaneous high-dose calcium supplements that could precipitate hypercalcaemia. If a dose is missed, the recommendation is to take it as soon as remembered unless the next scheduled dose is within a few hours; in that case, skip the missed dose and resume the regular schedule.

Never alter the prescribed regimen without consulting a clinician, as dosing errors can lead to serious electrolyte disturbances.

Safety Profile & Considerations

Common Side Effects

• Hypercalcaemia (elevated calcium) - reported in >10 % of patients during dose-escalation phases.
• Nausea - observed in approximately 8 % of trial participants.
• Headache - occurs in 5-7 % of users.
• Muscle weakness - noted in 4 % of subjects, generally mild and transient.

These effects are usually dose-related and resolve with adjustment.

Serious Adverse Events

Rare but severe reactions include nephrocalcinosis, vascular calcification, and life-threatening hypercalcaemic crisis. Immediate medical evaluation is required if symptoms such as severe abdominal pain, persistent vomiting, confusion, or cardiac arrhythmia develop.

Contraindications

Alfacalcidol should not be used in individuals with known hypersensitivity to the drug, active hypercalcaemia, or untreated hyperparathyroidism unrelated to CKD. It is also contraindicated in patients with granulomatous diseases (e.g., sarcoidosis) where ectopic vitamin D activation can occur.

Drug Interactions

• CYP450 inhibitors (e.g., ketoconazole, erythromycin) may raise alfacalcidol plasma levels, increasing hypercalcaemia risk.
• Loop diuretics (furosemide) can augment calcium excretion, potentially counteracting the drug’s effect.
• Other vitamin D analogues (calcitriol, paricalcitol) should not be combined unless under strict specialist supervision, to avoid additive calcium elevation.

Special Populations

• Pregnancy & Breastfeeding: Safety data are limited; the TGA advises use only if the potential benefit outweighs risk.
• Elderly: Renal function decline warrants lower starting doses and closer monitoring.
• Hepatic impairment: No dosage adjustment is typically required because alfacalcidol bypasses hepatic activation.
• Renal impairment: Dosing must be individualized; patients on dialysis often require lower doses to prevent hypercalcaemia.

Frequently Asked Questions

• How does alfacalcidol differ from calcitriol? Alfacalcidol requires only one hydroxylation step (in the liver) to become the active hormone, whereas calcitriol is already fully activated. This makes alfacalcidol useful in patients with reduced renal 1-α-hydroxylase activity, such as those on dialysis.

• How long does alfacalcidol take to work for hypocalcaemia? Serum calcium typically begins to rise within 24-48 hours, with noticeable clinical improvement often evident after 3-5 days of consistent dosing.

• What is the long-term safety of alfacalcidol? Long-term studies spanning up to five years show stable calcium-phosphate balance when doses are carefully titrated. The main safety concerns remain hypercalcaemia and vascular calcification, which are mitigated by regular laboratory monitoring.

• What should I do if I experience nausea while taking alfacalcidol? Minor nausea is common and may lessen as the body adjusts. If the symptom persists or worsens, contact your healthcare provider; they may recommend dose reduction or an alternative administration schedule.

• Does taking alfacalcidol with food affect its absorption? Food does not significantly impact absorption, but taking the tablet with a meal can reduce gastrointestinal irritation and improve patient comfort.

• Can I take calcium supplements while on alfacalcidol? Low-dose calcium (≤500 mg/day) is usually safe and may be needed to achieve target serum levels. High-dose calcium should be avoided unless expressly directed by a clinician, as it raises hypercalcaemia risk.

• Are there any foods I should avoid while using alfacalcidol? There are no strict food restrictions, but excessive intake of fortified dairy products or high-vitamin D foods might increase calcium levels. Discuss dietary habits with your physician to tailor supplementation.

• Is alfacalcidol suitable for patients with sarcoidosis? No; granulomatous diseases can cause uncontrolled conversion of vitamin D precursors, leading to dangerous calcium elevations. Alternative therapies are recommended.

• What monitoring is required during alfacalcidol therapy? Regular blood tests for serum calcium, phosphate, and PTH every 4-6 weeks during dose adjustments, then every 3-6 months once stable.

• What information should I provide my doctor when discussing alfacalcidol?

  • Complete list of current medications, including over-the-counter supplements.
  • Recent laboratory results (calcium, phosphate, PTH, renal function).
  • History of kidney disease, bone disorders, or calcium-related conditions.
  • Any previous episodes of hypercalcaemia or vitamin D toxicity.

Disclaimer

The information provided about alfacalcidol is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing alfacalcidol for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing alfacalcidol.

External Resources about Alfacalcidol

• Alfacalcidol | Memorial Sloan Kettering Cancer Center
• Alfacalcidol capsules (One-Alpha®) | CUH
• Alfacalcidol Patient Information Leaflet
• ALFACALCIDOL 0.5 MICROGRAMSCAPSULES SOFT - Patient leaflet, side effects, dosage | Patient info
• Patient Information - Alfacalcidol
• 131-Sandoz Alfacalcidol PMe clean 2024-05-16
• Alfacalcidol: Uses, Dosage, Side Effects, Food Interaction & FAQ