Conversion of oral alfacalcidol to oral calcitriol in the treatment of secondary hyperparathyroidism in chronic hemodialysis patients.
OBJECTIVE
The optimal vitamin D3therapy for the treatment of secondary hyperparathyroidism (SHPT) in chronic hemodialysis patients is still controversial. Recent studies suggest that uremia in end-stage renal disease is associated with enzymatic hepatic dysfunction altering 25-hydroxylation of vitamin D3. The goal of our study was to compare the efficacy of calcitriol, the fully hydroxylated active form of vitamin D3, to alfacalcidol which needs 25-hydroxylation to be effective, for the treatment of SHPT in chronic hemodialysis patients.


METHODS
We retrospectively reviewed 45 chronic hemodialysis patients who were switched from oral alfacalcidol to oral calcitriol for the treatment of SHPT. Parathyroid hormone (PTH), serum calcium and serum phosphorus levels were compared pre- and post-conversion using paired Student's t tests.


RESULTS
The mean dose of active vitamin D3decreased from 3.50 mcg/week at baseline to 2.86 mcg (P < 0001) after the switch from alfacalcidol to calcitriol. PTH significantly decreased from 94.4 to 82.6 pmol/L (-11.8 pmol/L, P = 0.02). The mean corrected calcium increased from 2.17 to 2.25 mmol/L (+0.08 mmol/L, P < 0.001) without any clinically significant hypercalcemia, and phosphorus levels were stable. Results were similar in a subgroup of patients (n = 17) for whom the medication was administrated during the hemodialysis session, ensuring a complete compliance.


CONCLUSIONS
According to our study, calcitriol in equal dosage is more effective than alfacalcidol in lowering serum PTH level in chronic hemodialysis patients. This suggests that calcitriol may be the optimal active vitamin D3for the treatment of SHPT in chronic hemodialysis patients.
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Sandrine
S
Rauscher
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Jean-Philippe
JP
Lafrance
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Vincent
V
Pichette
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Robert Z
RZ
Bell
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Katherine
K
Desforges
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Laurence
L
Lepage
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Georges
G
Ouellet
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Denis
D
Ouimet
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Martine
M
Leblanc
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Caroline
C
Lamarche
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada.
Sarah
S
Bezzaoucha
Division of Nephrology, Maisonneuve-Rosemont HospitalUniversity of Montreal, 5415 Assomption Blvd, Montreal, QC, H1T 2M4, Canada. mvallee.hmr@ssss.gouv.qc.ca.
Michel
http://orcid.org/0000-0002-4856-5057
M
Vallee
D000328:Adult; D000368:Aged; D002117:Calcitriol / Q000008:administration & dosage / Q000493:pharmacokinetics; D002118:Calcium / Q000097:blood; D002170:Canada; D016903:Drug Monitoring / Q000379:methods; D057915:Drug Substitution / Q000379:methods*; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000493:pharmacokinetics; D006962:Hyperparathyroidism, Secondary / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D063868:Patient Outcome Assessment; D010758:Phosphorus / Q000097:blood; D006435:Renal Dialysis / Q000009:adverse effects* / Q000379:methods; D012189:Retrospective Studies
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D010758:Phosphorus; D002117:Calcitriol; D002118:Calcium; C008088:alfacalcidol
Mineral bone metabolism; Secondary hyperparathyroidism; Vitamin D3