title: Efficacy and tolerability of intravenous paricalcitol in calcitriol-resistant hemodialysis patients with secondary hyperparathyroidism: 12-month prospective study.
abstract: OBJECTIVE
  Data are limited regarding the use of paricalcitol in calcitriol-resistant patients with secondary hyperparathyroidism (SHPT). We aimed to evaluate the effects of paricalcitol in calcitriol-resistant hemodialysis patients with SHPT.
  
  
  METHODS
  This is a 12-month, open-label, prospective study. Forty patients with calcitriol-resistant and/or calcitriol-intolerant SHPT were included. After a washout period, all patients converted to paricalcitol with a 1:3 conversion ratio. Serum calcium and phosphorus were monitored monthly, while serum intact parathyroid hormone (iPTH) once in every 3 months. Paricalcitol dose was reduced or discontinued in case of hypercalcemia and/or hyperphosphatemia. Pre- and posttreatment electrolyte and iPTH values were compared with Student's t-test and Wilcoxon signed-rank test, respectively.
  
  
  RESULTS
  Forty patients completed the study. Mean initiation dose of paricalcitol was 23 ± 7 μg/week. Mean serum calcium was 8.9 ± 0.8 mg/dL at baseline and 9.4 ± 0.7 mg/dL at study end (p = 0.07). Mean monthly serum phosphorus levels stayed stable. Paricalcitol was effective in reducing iPTH levels when compared with pretreatment values (747.9 ± 497.2 pg/mL, 307.3 ± 417.1 pg/mL, respectively; p < 0.001). Thirty-two patients had to discontinue intravenous (IV) paricalcitol at some time during their treatment. Main reasons for discontinuation were as follows: hyperphosphatemia (58%), hypercalcemia (25%), and iPTH < 150 pg/mL (17%).
  
  
  CONCLUSIONS
  Paricalcitol was found to be effective in reducing iPTH levels in calcitriol-resistant patients with SHPT despite relatively frequent drug discontinuation rates.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Meram School of Medicine, Selcuk University, Meram, Konya, Turkey.
authors.forename: Halil Zeki
authors.initials: HZ
authors.lastname: Tonbul
authors.forename: Yalcin
authors.initials: Y
authors.lastname: Solak
authors.forename: Huseyin
authors.initials: H
authors.lastname: Atalay
authors.forename: Kultigin
authors.initials: K
authors.lastname: Turkmen
authors.forename: Lutfullah
authors.initials: L
authors.lastname: Altintepe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002117:Calcitriol / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000187:drug effects*; D004361:Drug Tolerance; D004872:Ergocalciferols / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000209:etiology / Q000628:therapy*; D007275:Injections, Intravenous; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D050071:Bone Density Conservation Agents; D004872:Ergocalciferols; D010281:Parathyroid Hormone; C084656:paricalcitol; D002117:Calcitriol