Calcitriol Therapy for ESRD Patients

Introduction to Calcitriol Therapy

The American Journal of Kidney Diseases recommends an initial calcitriol dosage of 0.5-1.0 μg administered intravenously three times weekly after dialysis sessions for ESRD patients with a PTH level of 974 pg/mL 1, 2
Patients treated with hemodialysis who have intact PTH levels >300 pg/mL should receive an active vitamin D sterol, such as calcitriol, to reduce PTH to a target range of 150-300 pg/mL 1

Intermittent intravenous administration of calcitriol is more effective than daily oral calcitriol in lowering serum PTH levels 1
For a patient with severe hyperparathyroidism (PTH 974 pg/mL), the intravenous route is preferred as it provides better pharmacokinetics and more rapid PTH reduction 3

Serum calcium and phosphorus should be monitored at least every 2 weeks for the first month after initiating therapy, then monthly thereafter 2
PTH levels should be measured monthly for at least 3 months, then every 3 months once target levels are achieved 2
Target PTH range for dialysis patients is 150-300 pg/mL 1
If PTH falls below target range (150 pg/mL), hold calcitriol until PTH rises above target, then resume at half the previous dose 2
If corrected calcium exceeds 9.5 mg/dL, hold calcitriol until calcium returns to <9.5 mg/dL, then resume at half the previous dose 1
If phosphorus rises to >4.6 mg/dL, hold calcitriol, increase phosphate binder dose until phosphorus falls to <4.6 mg/dL, then resume prior calcitriol dose 1

Avoid initiating calcitriol if serum calcium >9.5 mg/dL or phosphorus >4.6 mg/dL 4
Ensure adequate phosphate binder therapy before and during calcitriol treatment 1
Maintain dialysate calcium concentration at 2.5 mEq/L (1.25 mmol/L) 1