Cinacalcet

Indications

Cinacalcet is used for: Hyperparathyroidism, Hypercalcemia, Parathyroid carcinoma

Adult Dose

Secondary Hyperparathyroidism (HPT) Indicated for secondary HPT in patients with chronic kidney disease on dialysis Initial dose: 30 mg PO qDay May increase if needed by titrating at 2-4 week intervals through sequential doses of 60, 90, 120, or 180 mg qDay Hypercalcemia in Patients with Parathyroid Carcinoma Initial dose: 30 mg PO q12hr May increase if needed at 2-4 week intervals through sequential doses 60 mg q12hr, 90 mg q12hr, or 90 mg q6-8hr as necessary to normalize serum calcium levels Hypercalcemia With Primary Hyperparathyroidism (HPT) Indicated for severe hypercalcemia in patients with primary HPT who are unable to undergo parathyroidectomy Initial dose: 30 mg PO q12hr May increase if needed at 2-4 week intervals through sequential doses 60 mg q12hr, 90 mg q12hr, or 90 mg q6-8hr as necessary to normalize serum calcium levels

Child Dose

Renal Dose

Renal Impairment Dose adjustment not necessary

Administration

Should be taken with food. Take w/ food or shortly after food. Swallow whole, do not divide.

Contra Indications

Hypersensitivity.

Precautions

Moderate-to-severe hepatic impairment, CV diseases. Not indicated for chronic kidney disease patients who are not receiving dialysis. Do not initiate Cinacalcet in hypocalcaemic patients. For secondary hyperparathyroidism, measure serum calcium and phosphorus (prior to- and within 1 wk after initiation/dose adjustment; mthly during maintenance) and iPTH (prior to- and within 1-4 wk after initiation/dosage adjustment; every 1-3 mth during maintenance). iPTH levels should drawn at least 12 hr after Cinacalcet dosing. For parathyroid carcinoma and primary parathyroidism, measure serum calcium prior-to and within 1 wk after initiation/dose adjustment; and every 2-3 mth during maintenance. Vitamin D sterols, calcium-containing phosphate binder and/or adjustment of calcium contents of dialysis fluid can be used to raise serum calcium in the event of hypocalcaemia. Reduce dose or withhold therapy if hypocalcaemia persists; may reinstate treatment at the next lowest dose after calcium levels normalised. Significant reduction in serum calcium may lower seizure threshold. Adynamic bone disease may develop if iPTH level is suppressed to < 100 pg/mL. May decrease total and free testosterone levels. Safety and efficacy not established in patients ?18 yr. Pregnancy and lactation. Lactation: excretion in milk unknown/not recommended

Pregnancy-Lactation

Interactions

Cinacalcet is a strong CYP2D6 inhibitor and may increase serum concentrations of amitriptyline, nortriptyline and desipramine. Cinacalcet may decrease serum concentrations of tacrolimus. CYP3A4 inhibitors such as ketoconazole, erythromycin may increase plasma concentrations of Cinacalcet.

Adverse Effects

Side effects of Cinacalcet : >10% Secondary Parathyroidism Diarrhea (20%),Nausea (19%),Vomiting (15%),Myalgia (14%) 1-10% Secondary Parathyroidism Dizziness (8%),Hypertension (5%),Access infection (4%),Anorexia (4%),Asthenia (4%),Noncardiac chest pain (4%),Seizures 1.4% Frequency Not Defined Parathyroid CA Nausea/vomiting,Hypocalcemia Potentially Fatal: Hypersensitivity reaction including angioedema.

Mechanism of Action

Cinacalcet is a calcimimetic agent. It lowers parathyroid hormone (PTH) secretion by increasing the sensitivity of the calcium-sensing receptor of the parathyroid gland to activation by extracellular calcium. PTH reduction leads to concomitant decrease in serum calcium and phosphorus concentrations.