1.
Pharmacokinetic and Pharmacodynamic Properties of Cinacalcet (KRN1493) in Chinese Healthy Volunteers: A Randomized, Open-label, Single Ascending-dose and Multiple-dose, Parallel-group Study.
Liu, H, Wang, H, Liu, T, Jiang, J, Chen, X, Gao, F, Hu, P
Clinical therapeutics. 2016;(2):348-57
Abstract
PURPOSE The aim of this study was to assess the pharmacokinetic (PK) and pharmacodynamic (PD) properties and safety of single and multiple doses of cinacalcet in Chinese healthy volunteers (HVs) for the purposes of a New Drug Application package for the Chinese Food and Drug Administration. METHODS In this randomized, open-label, single ascending-dose and multiple-dose, parallel-group study, 42 Chinese HVs were randomized to receive a single oral dose of 25, 50, or 100 mg of cinacalcet and multiple doses of 50 mg of cinacalcet once daily for 7 days. Plasma cinacalcet concentrations were analyzed by HPLC-MS/MS. The PK parameters were assessed with noncompartmental analysis. Plasma intact parathyroid hormone, serum calcium, and phosphorus concentrations were measured for PD evaluation. The safety profile was also assessed. Adverse events (AEs) were noted during the study. FINDINGS Of the 42 randomized HVs, 41 completed the study per protocol; 1 prematurely discontinued the study because of AEs. Cinacalcet has nonlinear PK properties over a dose range of 25 to 100 mg after a single dose. Mean (SD) Cmax values were 7.68 (4.25), 17 (6.33), and 31.3 (16.42) ng/mL with single doses of 25, 50, and 100 mg of cinacalcet, respectively. Mean (SD) AUC0- last values were 58.4 (25.38), 187 (70.7), and 367 (180.03) hr∙ng/mL with single doses of 25, 50, and 100 mg of cinacalcet, respectively. Steady state was attained within 7 doses of successive daily administration of 50 mg of cinacalcet. At steady state, the mean (SD) Cmax and AUC0-last values were 20.6 (9.63) ng/mL and 297 (146.15) ng∙h/mL. The accumulation ratios of Cmax and AUC (AUCτ/AUC0-24) were 1.21 and 1.32. Plasma intact parathyroid hormone and serum calcium concentrations had similar patterns, both decreased after administration of cinacalcet, whether after single dose or multiple doses. A total of 52 AEs were reported in 20 HVs (47.6%). The most frequently reported AEs after single-dose and multiple-dose cinacalcet administration were hypocalcemia, numbness, dizziness, and muscle soreness. No serious AEs were reported. IMPLICATIONS Cinacalcet was well tolerated and effective after administration of a single oral dose up to 100 mg and multiple doses of 50 mg of cinacalcet once daily for 7 days. Cinacalcet has nonlinear PK properties over a dose range of 25 to 100 mg after a single dose. PK profiles after multiple doses were similar to those after a single dose with no accumulation. Cinacalcet had similar PK and safety profiles between Chinese and Western HVs at the same dose levels.
2.
Vitamin D, secondary hyperparathyroidism, and preeclampsia.
Scholl, TO, Chen, X, Stein, TP
The American journal of clinical nutrition. 2013;(3):787-93
-
-
Free full text
-
Abstract
BACKGROUND Secondary hyperparathyroidism, which is defined by a high concentration of intact parathyroid hormone when circulating 25-hydroxyvitamin D [25(OH)D] is low, is a functional indicator of vitamin D insufficiency and a sign of impaired calcium metabolism. Two large randomized controlled trials examined effects of calcium supplementation on preeclampsia but did not consider the vitamin D status of mothers. OBJECTIVE We examined the association of secondary hyperparathyroidism with risk of preeclampsia. DESIGN Circulating maternal 25-hydroxyvitamin D [25(OH)D] and intact parathyroid hormone were measured at entry to care (mean ± SD: 13.7 ± 5.7 wk) using prospective data from a cohort of 1141 low-income and minority gravidae. RESULTS Secondary hyperparathyroidism occurred in 6.3% of the cohort and 18.4% of women whose 25(OH)D concentrations were <20 ng/mL. Risk of preeclampsia was increased 2.86-fold (95% CI: 1.28-, 6.41-fold) early in gestation in these women. Gravidae with 25(OH)D concentrations <20 ng/mL who did not also have high parathyroid hormone and women with high parathyroid hormone whose 25(OH)D concentrations were >20 ng/mL were not at increased risk. Intact parathyroid hormone was related to higher systolic and diastolic blood pressures and arterial pressure at week 20 before clinical recognition of preeclampsia. Energy-adjusted intakes of total calcium and lactose and circulating 25(OH)D were correlated inversely with systolic blood pressure or arterial pressure and with parathyroid hormone. CONCLUSION Some women who are vitamin D insufficient develop secondary hyperparathyroidism, which is associated with increased risk of preeclampsia.
3.
Evaluation of anemia and serum iPTH, calcium, and phosphorus in patients with primary glomerulonephritis.
Li, Y, Zhang, W, Ren, H, Wang, W, Shi, H, Li, X, Chen, X, Shen, P, Wu, X, Xie, J, et al
Contributions to nephrology. 2013;:31-40
Abstract
Glomerulonephritis (GN) remains a major cause of morbidity and mortality in chronic kidney disease (CKD). Our study aimed to investigate the prevalence of anemia, abnormal serum intact parathyroid hormone (iPTH), calcium, and phosphorus in a Chinese patient population with primary GN. Medical histories and laboratory test results were collected from 2,924 patients with primary GN hospitalized in Ruijin Hospital of Shanghai between January 2003 and August 2009. The leading cause of CKD was primary glomerular diseases, which were responsible for up to 53.5% of all cases. IgA nephropathy was the most common cause, accounting for 38.7%, followed by focal segmental glomerulosclerosis (FSGS). The anemia rate of GN patients in early stages of CKD (stages 1-2 and 3) was 16-36%, and rapidly accelerated to 65.8 and 80.2% in advanced CKD stage 4 and stage 5, respectively. There was no significant decline observed in the level of serum calcium in patients with CKD stages 1-4 (p > 0.05). However, in patients with CKD stage 5 the prevalence of hypocalcaemia increased significantly (13.7%, p = 0.000). The prevalence of hyperphosphatemia did not significantly increase in patients with CKD stages 1-3 (p < 0.05), but was much higher in patients with CKD stages 4 and 5 (p = 0.001 and p = 0.021, respectively) and showed a negative correlation with renal function. Serum iPTH levels did not increase significantly in GN patients with CKD stages 1-2. The median iPTH levels were 54.7, 88.6, and 289.2 pg/ml (p = 0.000) for CKD stages 3-5, respectively, all of which showed negative correlation with renal function. The proportion of vitamin D insufficiency and deficiency increased to 29.3 and 11.2%, respectively, as the glomerular filtration rate fell below 15 ml/min/1.73 m(2). Primary glomerular disease remains the major cause of CKD in China, and complications such as anemia and metabolic bone disease are frequently present in GN patients.