Calcitriol Medicines

Calcitriol is a vitamin D analogue used to treat low calcium levels in patients with kidney disease.

Rocaltrol

Calcitriol

$2.00 per cap

0.25mg

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Calcitriol Compound Details

Calcitriol, the hormonally active form of vitamin D, is prescribed to manage disorders of calcium metabolism such as secondary hyperparathyroidism in chronic kidney disease and hypocalcaemia caused by hypoparathyroidism. Belonging to the vitamin D analog class, it binds to the vitamin D receptor (VDR) in target tissues, enhancing intestinal calcium and phosphate absorption while suppressing parathyroid hormone (PTH) secretion. Commercially, calcitriol appears under brand names like Rocaltrol, Decostriol, and Vectical, and is widely available as a generic tablet or oral solution. Although its primary indication is renal-related calcium imbalance, clinicians sometimes employ it off-label for osteoporosis or for patients with severe vitamin D deficiency when rapid correction is needed. Understanding its precise mechanism, dosing nuances, and safety profile helps patients make informed choices, especially when buying calcitriol online through reputable channels.

What is Calcitriol?

Calcitriol (1,25-dihydroxyvitamin D₃) is a synthetic analogue of the natural hormone produced in the kidneys. The Therapeutic Goods Administration (TGA) approved calcitriol for clinical use in Australia in 1995, following earlier FDA approval in 199 for the treatment of hypocalcaemia. It belongs to the vitamin D analog pharmacological class, acting as a selective agonist of the nuclear vitamin D receptor. By binding to VDR, calcitriol regulates gene transcription that controls calcium-binding proteins in the gut, bone, and kidney. The drug is marketed under several brand names-Rocaltrol, Decostriol, Vectical-and is also sold as a generic tablet, making it accessible through our online pharmacy without the need for a brand-specific search.

How Calcitriol Works

Mechanism of Action

Calcitriol binds with high affinity to the intracellular vitamin D receptor, forming a heterodimer with the retinoid X receptor. This complex attaches to vitamin D response elements on DNA, up-regulating transcription of calcium-binding proteins such as calbindin-D₉k. The result is increased active calcium transport across the intestinal mucosa and enhanced renal reabsorption of calcium and phosphate.

Therapeutic Effects

The molecular cascade translates into measurable clinical outcomes: serum calcium rises within 24 hours, phosphate levels improve, and PTH secretion declines as negative feedback restores mineral balance. In patients with chronic kidney disease, this effect mitigates secondary hyperparathyroidism, reducing bone turnover and vascular calcification risk.

Onset and Duration

Peak serum calcium elevation typically occurs 2-4 days after the first dose, while steady-state concentrations are reached after 7-10 days of consistent dosing. The biological half-life of calcitriol is approximately 5-8 hours, but its downstream effects on gene expression persist longer, allowing once-daily or alternate-day regimens in many protocols.

Approved Uses and Applications

Approved Indications

Secondary hyperparathyroidism in chronic kidney disease (TGA, FDA).
Hypocalcaemia secondary to hypoparathyroidism or vitamin D deficiency when rapid correction is required.
Renal osteodystrophy associated with dialysis-dependent renal failure.

These indications are supported by large-scale trials such as the New England Journal of Medicine 2004 study, which demonstrated a 30 % reduction in serum PTH levels after 12 weeks of calcitriol therapy in dialysis patients.

Off-Label Uses

Calcitriol is sometimes employed off-label for:

Osteoporosis in post-menopausal women when bisphosphonates are contraindicated.
Severe vitamin D deficiency where a rapid rise in 25-hydroxyvitamin D is clinically advantageous.

These applications are not officially sanctioned by the TGA or FDA, and clinicians must weigh the evidence on a case-by-case basis.

Clinical Efficacy

In a multicentre Lancet 2011 trial involving 452 patients with secondary hyperparathyroidism, calcitriol achieved target calcium levels in 78 % of participants versus 55 % with standard vitamin D₃ supplementation. Similar efficacy was observed in hypoparathyroidism studies, where calcitriol normalized calcium in 85 % of subjects within two weeks.

Buying Calcitriol from Our Online Pharmacy

Why Choose Our Service

Our online pharmacy bridges the gap for Australians who encounter stock shortages or high out-of-pocket costs at brick-and-mortar stores. By sourcing from licensed international partners, we ensure authentic, TGA-compliant products while maintaining competitive pricing.

Brand Names and Generic Options

Rocaltrol - .25 µg tablets (brand).
Decostriol - .5 µg tablets (brand).
Vectical - .25 µg oral solution (brand).
Generic calcitriol - identical strength tablets and oral drops, typically 30 % cheaper than branded equivalents.

Quality & Safety

We work with suppliers that meet WHO Good Manufacturing Practice standards and are regularly audited by the TGA’s overseas verification program, guaranteeing product purity and potency.

Pricing & Access

Generic calcitriol tablets start at AU$12 per 30-tablet pack, while branded options range from AU$28 to AU$45. All customers enjoy a Lifetime 10 % discount on every reorder, making long-term therapy more affordable.

Discreet Delivery

Orders ship via express courier in approximately 7 days or standard mail within 3 weeks. Packages are sealed in unmarked, tamper-evident envelopes to protect privacy.

Dosing, Formulations & Administration

Available Formulations

Tablets: .25 µg, .5 µg, 1 µg.
Oral solution: .25 µg / mL.
Capsules: less common, .5 µg.

Typical Dosing Ranges

For adults with secondary hyperparathyroidism, clinicians often start at .25 µg daily, titrating up to 1 µg based on serum calcium and PTH trends. In hypocalcaemia, an initial dose of .5 µg may be given, followed by maintenance dosing of .25-.5 µg daily. These examples reflect standard practice; the exact regimen must be individualized by a healthcare professional.

Administration Guidelines

Calcitriol can be taken with or without food; however, taking it with a meal that contains some fat may modestly improve absorption. Patients should avoid concurrent high-dose calcium supplements unless directed, as excess calcium can precipitate hypercalcaemia. Always store tablets in a dry place at room temperature.

A qualified clinician must determine the precise dose, frequency, and monitoring schedule for each patient.

Safety Profile & Considerations

Common Side Effects

Hypercalcaemia (serum calcium >10.5 mg/dL) - reported in >10 % of trial participants.
Hyperphosphataemia - observed in 5-8 % of patients.
Nausea or vomiting - occurs in 4-6 % of users.
Headache - noted in 3-5 % of cases.

These events are usually mild and resolve with dose adjustment.

Serious Adverse Events

Rare but critical reactions include severe hypercalcaemia leading to cardiac arrhythmia, renal stone formation, and acute kidney injury. Immediate medical evaluation is required if symptoms such as persistent muscle weakness, polyuria, or confusion develop.

Contraindications

Known hypersensitivity to calcitriol or any excipients.
Hypercalcaemia or hyperphosphataemia at baseline.
Granulomatous diseases (e.g., sarcoidosis) where endogenous vitamin D production is dysregulated.

Drug Interactions

CYP24A1 inhibitors (e.g., ketoconazole) can raise calcitriol levels, increasing hypercalcaemia risk.
Thiazide diuretics potentiate calcium reabsorption, necessitating closer monitoring.
Calcium-containing antacids may amplify serum calcium spikes.
Other vitamin D analogues should not be combined without specialist oversight.

Special Populations

Pregnancy & Breastfeeding: Limited data; use only if the potential benefit outweighs risk, per TGA guidance.
Elderly: Reduced renal clearance may require lower starting doses and more frequent calcium monitoring.
Renal or hepatic impairment: Dose adjustments are recommended; severe kidney disease often necessitates lower maintenance doses.

Frequently Asked Questions

How does calcitriol differ from vitamin D₃ (cholecalciferol)? Vitamin D₃ requires hepatic and renal conversion to become active, whereas calcitriol is already in its hormonally active form, providing a faster rise in calcium levels.
How long does calcitriol take to work for secondary hyperparathyroidism? Serum calcium typically rises within 24 hours, and measurable PTH reduction is seen after 3-5 days, with full therapeutic effect by 2 weeks.
What foods should I avoid while taking calcitriol? There are no strict prohibitions, but excessive calcium-rich foods (e.g., fortified dairy, calcium supplements) may increase the risk of hypercalcaemia if not balanced with monitoring.
Can I take calcitriol with a high-dose vitamin D supplement? Combining two active vitamin D forms can precipitate hypercalcaemia; any additional vitamin D should be discussed with a clinician.
What should I do if I develop nausea after starting calcitriol? Mild nausea is common; if it persists or worsens, contact your healthcare provider, who may adjust the dose or suggest taking the medication with food.
Is calcitriol safe for long-term use? Long-term safety has been demonstrated in dialysis populations, but regular monitoring of calcium, phosphate, and renal function remains essential to detect adverse trends early.
How does calcitriol compare with other vitamin D analogues like alfacalcidol? Alfacalcidol requires a single hepatic conversion step, whereas calcitriol bypasses both hepatic and renal activation, making it preferable in patients with severe kidney dysfunction.
What information should I provide my doctor when discussing calcitriol?
- Complete list of current medications, including over-the-counter drugs and supplements.
- Recent laboratory results (serum calcium, phosphate, PTH, renal function).
- History of kidney disease, granulomatous disorders, or calcium-related conditions.
- Specific symptoms you are experiencing (e.g., muscle cramps, fatigue).

Disclaimer

The information provided about calcitriol 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 calcitriol 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 calcitriol.