Active Vitamin D Analogue (CKD-MBD / Secondary Hyperparathyroidism) Pregnancy: Safety in pregnancy not established; use only if benefits outweigh potential risk to the foetus. May breastfeed while taking calcitriol provided maternal and infant serum calcium are monitored.

Calcitriol

Brand names: Rocaltrol, Calcijex (IV)

Calcitriol is the active form of vitamin D (1,25-dihydroxycolecalciferol) used in renal practice to treat secondary hyperparathyroidism and hypocalcaemia of chronic kidney disease, where renal activation of vitamin D is impaired.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 0.25 mcg daily (initial); most patients respond to 0.5-1.0 mcg daily

Route: Oral

Frequency: Once daily (or 0.25 mcg every other day if calcium normal/only slightly reduced)

Max: Refractory osteodystrophy pulse therapy: maximum total cumulative dose of 12 mcg per week should not be exceeded

Renal osteodystrophy (variant of calcitriol; extracted from the same Calcitriol capsule SPC). Initial 0.25 mcg/day; in patients with normal or only slightly reduced calcium, 0.25 mcg every other day is sufficient. If no satisfactory response within 2-4 weeks, increase by 0.25 mcg at 2-4 week intervals, monitoring serum calcium at least twice weekly. Oral pulse therapy for osteodystrophy refractory to continuous therapy: initial 0.1 mcg/kg/week split into two or three equal doses given at the end of dialysis (max 12 mcg/week). Stop immediately if serum calcium rises 1 mg/100 ml (250 micromol/l) above normal or serum creatinine rises to 120 micromol/l, until normocalcaemia returns. Dose must be individually adjusted to biological response; ensure adequate calcium intake.

Dose adjustments

Renal

Intended for renal osteodystrophy in dialysis patients. In renal failure, caution due to danger of ectopic calcification; maintain plasma phosphate at normal level with phosphate-binding agents and low-phosphate diet. Discontinue if serum creatinine rises to 120 micromol/l until normocalcaemia returns.

Dose auto-extracted from clinician-entered (no bundle on file) — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to calcitriol (or drugs of the same class) or any excipient
All diseases associated with hypercalcaemia
Evidence of metastatic calcification
Evidence of vitamin D toxicity

Side effects

Hypercalcaemia (most commonly reported)
Headache; decreased appetite; abdominal pain, nausea, vomiting, constipation
Rash, erythema, pruritus, urticaria (hypersensitivity)
Cardiac arrhythmias; muscular weakness, sensory disturbance, somnolence
Polyuria, nocturia, urinary tract infection; blood creatinine increased

Interactions

Other vitamin D compounds/derivatives and vitamin-D-fortified foodstuffs should be withheld during treatment (risk of hypervitaminosis D)
Phosphate-binding agents may be needed to control serum phosphate in renal failure
Switching from long-acting vitamin D (ergocalciferol/colecalciferol) increases hypercalcaemia risk for several months
See SPC section 4.5 for dose adjustments related to drug interactions

Clinical monograph

How it works

It binds the vitamin D receptor to increase intestinal calcium and phosphate absorption and directly suppress parathyroid hormone secretion, correcting the mineral disturbance of renal failure.

Prescribing in practice

Hypercalcaemia is the main hazard, often compounded by hyperphosphataemia, so monitor calcium and phosphate closely and reduce or withhold if they rise.
Because it acts independently of renal hydroxylation it does not need that activation step, but this also means its calcaemic effect can be rapid and pronounced.
Avoid concurrent high-dose calcium or other vitamin D products, and use caution with thiazides and digoxin given the hypercalcaemia and arrhythmia risk.

Monitoring

Monitor serum calcium, phosphate and parathyroid hormone regularly, adjusting therapy to avoid hypercalcaemia and oversuppression.

Counselling the patient

Attend for regular blood tests to check your calcium level.
Report nausea, constipation, excessive thirst or confusion, which can signal a high calcium level.
Do not take other calcium or vitamin D supplements unless advised.

Evidence & guidelines

Active vitamin D therapy for CKD mineral and bone disorder is supported by KDIGO and NICE CKD guidance.

Reference: KDIGO CKD-MBD Clinical Practice Guideline Update 2017; KDIGO CKD Guideline 2024; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways