Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Calcimimetics increase the sensitivity of parathyroid calcium-sensing receptors to extracellular calcium, thereby reducing PTH secretion. This multicenter, randomized, double-blind, placebo-controlled study assessed the ability of the oral calcimimetic cinacalcet HCl to achieve long-term reductions in serum calcium and PTH concentrations in patients with primary hyperparathyroidism (HPT). Patients (n = 78) were randomized to cinacalcet or placebo. Cinacalcet was titrated from 30-50 mg twice daily during a 12-wk dose-titration phase. Efficacy was assessed during 12-wk maintenance and 28-wk follow-up phases. The primary endpoint was the achievement of normocalcemia [serum calcium </= 10.3 mg/dl (2.57 mmol/liter)] with at least 0.5 mg/dl (0.12-mmol/liter) reduction from baseline. Plasma PTH, serum and urine biochemistry, biochemical measures of bone turnover, bone mineral density, and safety were also assessed. Seventy-three percent of cinacalcet-treated patients vs. only 5% of placebo-treated patients achieved the primary endpoint (P < 0.001). Fasting predose plasma PTH decreased 7.6% in cinacalcet patients but increased 7.7% in placebo patients (P < 0.01). Bone mineral density was unchanged by cinacalcet, but bone resorption and formation markers increased (P < 0.05). Adverse events were mild and similar between treatment groups. Cinacalcet rapidly normalizes serum calcium and reduces PTH in patients with primary HPT, and these effects are maintained with long-term treatment. Cinacalcet may be an effective, nonsurgical approach for management of primary HPT.
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PMID:Cinacalcet hydrochloride maintains long-term normocalcemia in patients with primary hyperparathyroidism. 1552 38

Cinacalcet HCl, an allosteric modulator of the calcium-sensing receptor (CaR), has recently been approved for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis, due to its suppressive effect on parathyroid hormone (PTH) secretion. Although cinacalcet's effects in patients with primary and secondary hyperparathyroidism have been reported, the crucial relationship between the effect of calcimimetics and CaR expression on the parathyroid glands requires better understanding. To investigate its suppressive effect on PTH secretion in primary hyperparathyroidism, in which hypercalcemia may already have stimulated considerable CaR activity, we investigated the effect of cinacalcet HCl on PTH-cyclin D1 transgenic mice (PC2 mice), a model of primary hyperparathyroidism with hypo-expression of CaR on their parathyroid glands. A single administration of 30 mg/kg body weight (BW) of cinacalcet HCl significantly suppressed serum calcium (Ca) levels 2 h after administration in 65- to 85-week-old PC2 mice with chronic biochemical hyperparathyroidism. The percentage reduction in serum PTH was significantly correlated with CaR hypo-expression in the parathyroid glands. In older PC2 mice (93-99 weeks old) with advanced hyperparathyroidism, serum Ca and PTH levels were not suppressed by 30 mg cinacalcet HCl/kg. However, serum Ca and PTH levels were significantly suppressed by 100 mg/kg of cinacalcet HCl, suggesting that higher doses of this compound could overcome severe hyperparathyroidism. To conclude, cinacalcet HCl demonstrated potency in a murine model of primary hyperparathyroidism in spite of any presumed endogenous CaR activation by hypercalcemia and hypo-expression of CaR in the parathyroid glands.
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PMID:Relationship between parathyroid calcium-sensing receptor expression and potency of the calcimimetic, cinacalcet, in suppressing parathyroid hormone secretion in an in vivo murine model of primary hyperparathyroidism. 1618 80

Cinacalcet is a new drug with antiparathyroid effects that belongs to the class of calcimimetics. It increases the sensitivity of the calcium-sensing receptor (CaSR) to calcium, thus inducing a decrease in plasma parathyroid (PTH) levels. In patients with uncontrolled secondary hyperparathyroidism due to uremia, cinacalcet has been shown to decrease the levels of PTH even in those optimally treated with calcium and 1-ahydroxylated vitamin D. Cinacalcet decreases plasma calcium and plasma PTH levels in patients with primary hyperparathyroidism or parathyroid cancer.
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PMID:[Cinacalcet--a new drug for the treatment of secondary hyperparathyroidism in patients with uraemia, parathyroid cancer or primary hyperparathyroidism]. 1639 59

Clinical studies have been performed to determine the effect of cinacalcet HCl (cinacalcet), an allosteric modulator of the calcium-sensing receptor (CaR), on primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism of uremia (SHPT). However, no in vitro studies on human parathyroid cells have been reported to date. In this study, the inhibitory effect of cinacalcet on PTH secretion was analyzed in primary cultured parathyroid cells obtained from patients. The investigation involved three PHPT and three SHPT patients subjected to therapeutic parathyroidectomy. Notably, all SHPT patients were resistant to intravenous vitamin D analogue therapy. Removed parathyroid tumors were used for immunohistochemistry and parathyroid cell primary culture. Immunohistochemical analyses revealed diminished expression of CaR and vitamin D receptor (VDR) in all parathyroid tumors. PTH secretion from cultured parathyroid cells of PHPT and SHPT patients was suppressed by extracellular Ca2+ and cinacalcet in a dose-dependent manner. Rates of suppression of PTH secretion in PHPT and SHPT by cinacalcet (1000 nmol/l) were 61% +/- 21% and 61% +/- 19%, respectively. Cinacalcet demonstrates significant potency in the suppression of PTH secretion in primary cultured human parathyroid cells in vitro, despite reduced levels of the target protein, CaR. Data from this in vitro analysis support the clinical application of cinacalcet in PHPT and SHPT therapy.
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PMID:Direct in vitro evidence of the suppressive effect of cinacalcet HCl on parathyroid hormone secretion in human parathyroid cells with pathologically reduced calcium-sensing receptor levels. 1681 24

Calcimimetics suppress the secretion of parathyroid hormone by sensitizing the parathyroid calcium receptor to serum calcium. Cinacalcet (Sensipar/Mimpara), Amgen Inc., Thousand Oaks, CA), the first-in-class calcimimetic agent approved for treatment of secondary hyperparathyroidism in dialysis patients, is, in association with higher dose of a calcium-based oral phosphate binder, a well-tolerated and effective alternative to standard treatments such as vitamin D derivatives in association with a non-calcium-based oral phosphate binder. Here, we present an overview of evidence in support of this assertion. We extend our discussion to encompass other indications for calcimimetics -- secondary hyperparathyroidism in predialysis chronic kidney disease patients, hypercalcemic hyperparathyroidism in renal transplant recipients, primary hyperparathyroidism, and hypercalcemia associated with parathyroid carcinoma -- as well as providing guidance on optimal usage of this drug.
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PMID:Drug Insight: renal indications of calcimimetics. 1693 53

Drugs for treating primary hyperparathyroidism can be divided into two main groups: (i) antiresorptive drugs that inhibit the increased bone turnover, which can be divided into estrogen-like compounds (estrogen, oral contraceptives and selective estrogen receptor modulators [SERMs]), bisphosphonates and calcitonin; and (ii) drugs that interfere with parathyroid hormone (PTH) secretion (currently only cinacalcet is available). No drugs that interfere with PTH action are currently available. Available studies suggest that all classes of drugs are able to lower serum calcium levels. However, calcitonin does so only temporarily. Estrogen-containing compounds (hormone replacement therapy) may be less attractive because of the potential risk of breast cancer, cardiovascular disease and deep vein thromboembolism. Oral contraceptives have not been shown to be able to prevent fractures in the general population, and no data are available on their effect in women with primary hyperparathyroidism. The only SERM marketed for hyperparathyroidism is raloxifene and this has not been associated with an increased risk of breast cancer and cardiovascular diseases, and has been shown to be able to prevent vertebral fractures in postmenopausal women with osteoporosis. Two small trials suggest that raloxifene may increase bone mineral density (BMD) and decrease serum calcium levels in patients with primary hyperparathyroidism. Bisphosphonates have been shown to decrease serum calcium and increase BMD in patients with primary hyperparathyroidism, but PTH levels may increase. Cinacalcet effectively induces a sustained decrease in serum calcium and PTH for up to 1 year. However, BMD does not seem to increase. No data on hard endpoints such as fractures, kidney stones, cardiovascular disease etc. are available for any of the drugs available for the treatment of primary hyperparathyroidism.
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PMID:Current pharmacological options for the management of primary hyperparathyroidism. 1713 3

Cinacalcet HCl reduces iPTH, serum calcium, serum phosphorus, and the calcium-phosphorus product in patients with chronic kidney disease and secondary hyperparathyroidism who are receiving dialysis, and reduces elevated serum calcium associated with primary hyperparathyroidism and parathyroid carcinoma. Cinacalcet is administered orally, and thus concomitant administration with food may affect its bioavailability. The objective of this study was to examine the effect of fat and caloric intake on cinacalcet exposure. This phase 1, randomized, open-label, single-dose, 3-period, 3-treatment, 6-sequence crossover study enrolled 30 healthy subjects (19 men, 11 women) to receive a single oral dose of cinacalcet HCl (Sensipar/Mimpara; Amgen Inc. Thousand Oaks, CA) (90 mg) on 3 separate occasions: following a high-fat, high-caloric meal, a low-fat, low-caloric meal, and a 10-hour fast. Blood samples were obtained predose and up to 72 hours postdose for pharmacokinetic (AUCinfinity, Cmax) and safety evaluations. Twenty-nine subjects completed all the 3 treatment conditions. The mean (90% confidence intervals) AUCinfinity following high- and low-fat meals was increased by 68 (48 to 89)% and 50 (33 to 70)%, respectively, relative to fasting. The difference in mean AUCinfinity between high- and low-fat meals was small [12 (9.9-26)%]. The mean tmax of cinacalcet was prolonged in fasting subjects (6 h) in relation to high-fat (4 h) and low-fat (3.5 h) fed subjects. The mean t1/2beta was similar between treatment conditions. Adverse events (AE) were observed at a similar frequency across the treatment conditions [high fat (34%), low fat (23%), and fasting (31%)]; the type of AE did not differ among the treatment conditions. The most common treatment-related AEs were headache 6/30 (20%), nausea 5/30 (17%), and dyspepsia 4/30 (13%) subjects. Administration of cinacalcet with either high- or low-fat meals results in significant increases in exposure, relative to administration under fasting conditions. However, the small differences observed in exposure following the ingestion of the different types of meals suggest that although food has a significant effect, the type of food does not. The observed effect supports the labeling statement that cinacalcet be taken with food, or shortly after a meal.
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PMID:The pharmacokinetics of cinacalcet are unaffected following consumption of high- and low-fat meals. 1751 96

The successful use of cinacalcet in dialysis patients and in patients with primary hyperparathyroidism has prompted transplant physicians to use it to treat renal-transplant patients with persisting hyperparathyroidism. However, in the setting of kidney transplantation, many questions remain unanswered, i.e. the time of initiation of cinacalcet after transplantation, its dosage and the side effects on kidney function all remain unknown. Herein, we report on a kidney-transplant recipient with persisting hyperparathyroidism who developed hypercalciuria afterreceiving high doses of cinacalcet. Cinacalcet was started 3 months after transplantation at a once-daily dose of 60 mg. Thereafter, the dosage was increased progressively because of persistant hyperparathyroidism and hypercalcemia. At a dose of 90 mg b.i.d, hypercalciuria occurred. The latter disappeared after reduction of cinacalcet dosage. Cinacalcet might be responsible for urinary calcium excretion, either by reduction of tubular calcium reabsorption via the reduction of PTH level, or by its direct effect on the calcium sensor receptor located in the upper thick ascending limb of the loop of Henle. We conclude that cinacalcet should be used with caution in renal-transplant patients. Further investigations are required to determine the best way to use this drug in this setting.
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PMID:Hypercalciuria induced by a high dose of cinacalcet in a renal-transplant recipient. 1796 93

Primary hyperparathyroidism (HPT) is the leading cause of hypercalcemia in the outpatient setting, and it is treated primarily by parathyroidectomy. There are few nonsurgical treatment options for patients who do not wish to have surgery, who have failed surgery, or who have contraindications to surgery. Cinacalcet increases the sensitivity of parathyroid calcium-sensing receptors to extracellular calcium, thereby reducing serum calcium levels. We conducted a retrospective chart review from 2004 to 2006 to investigate the efficacy of cinacalcet in reducing serum total calcium, ionized calcium, and parathyroid hormone (PTH) in patients with primary HPT. Patients were started on cinacalcet if they met at least one indication for parathyroidectomy, which includes T score less than -2.5 standard deviations from the mean, serum calcium 1 mg/dL above the upper limit of normal, 24-hour urine calcium above 400 mg/dL, age less than 50 years, or a creatinine clearance that is 30% below age- and sex-matched controls. The primary outcome was normalization of serum calcium. A total of 18 patients with primary HPT were started on cinacalcet: 16 men and 2 women with a mean age of 70 years. Mean baseline serum calcium was 10.60 +/- .53 mg/dL; ionized serum calcium, 1.45 +/- .07 mmol/L; and serum PTH, 141 +/- 78 pg/mL. After treatment with cinacalcet, the mean serum calcium decreased to 9.46 +/- .34 mg/dL, ionized calcium decreased to 1.26 +/- .06 mmol/L, and PTH decreased to 108 +/- 64.5 pg/mL. Ninety-four percent of the patients on cinacalcet had normal total serum calcium, 81% had normal serum ionized calcium, whereas only 25% had a normal serum PTH level. Cinacalcet normalizes serum calcium in most patients while only modestly reducing serum PTH levels.
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PMID:Cinacalcet for the treatment of primary hyperparathyroidism. 1832 54

Cinacalcet is a type II calcimimetic agent which is an allosteric modulator of the calcium-sensing receptor (CaR) located on the surface of the parathyroid cells. Cinacalcet increases the sensitivity of CaR via binding to the transmembrane region of CaR. Increasing sensitivity of CaR causes reduced secretion of parathyroid hormone (PTH) and suppression of serum calcium levels. Cinacalcet has recently been approved by Federal Drug Administration (FDA) for the treatment of patients with secondary hyperparathyroidism on maintenance dialysis and hypercalcemia in patients with parathyroid cancer. It is used also in Europe for both indications. Several controlled studies have shown that cinacalcet is effective in normalizing serum calcium levels also in primary hyperparathyroidism. Cinacalcet is metabolized primarily in the liver by N-dealkylation leading to carboxylic acid and oxidation of naphthalene ring to form dihydrodiols. The safety and optimal dosage of the drug in hypercalcemic patients with liver impairment remains unclear. We present a patient with Child-Pugh B class primary biliary cirrhosis who presented with moderate hypercalcemia and was diagnosed as primary hyperparathyroidism. As she refused having parathyroid surgery for her parathyroid adenoma at first, her hypercalcemia was treated successfully with 30 mg/day cinacalcet for 6 months. Cinacalcet was discontinued after 6 months. Her calcium level increased gradually. As she accepted surgery this time, her parathyroid adenoma was removed by minimally invasive parathyroidectomy. Parathyroid adenoma was confirmed pathologically. Her calcium levels maintained within the normal ranges after surgery.
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PMID:Hypercalcemia of primary hyperparathyroidism was treated by cinacalcet in a patient with liver cirrhosis. 1856 Oct 96


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