CINACALCET HYDROCHLORIDE
| CINACALCET HYDROCHLORIDE (sin-a-kal'set) Sensipar Classifications: hormone; parathyroid hormone agent; calcium receptor agonist; Therapeutic: parathyroid hormone agent Pregnancy Category: C |
Availability
30 mg, 60 mg, 90 mg tablets
Action
Directly lowers parathyroid hormone (PTH) levels by increasing the sensitivity of calcium-sensing receptors on the parathyroid gland to extracellular calcium. The reduction in PTH causes decreased calcium and phosphate adsorption from bone, and thus decreased serum calcium and phosphate levels. The drug is a calcium receptor agonist, also known as a calcimimetic agent.
Therapeutic Effect
Lowers PTH production; this also decreases rate of bone turnover and bone fibrosis in chronic renal failure disease (CRFD).
Uses
Treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis; hypercalcemia in patients with parathyroid cancer.
Contraindications
Hypersensitivity to cinacalcet; pregnancy (category C), lactation, children <18 y.
Cautious Use
Moderate and severe hepatic impairment, hypocalcemia, history of seizures.
Route & Dosage
| Secondary Hyperparathyroidism Adult: PO Start with 30 mg once daily; may increase q2–4wk until target iPTH of 150–300 pg/mL (max: 300 mg/d) Parathyroid Cancer Adult: PO 30 mg twice daily; titrate q2–4wk as 60 mg b.i.d., 90 mg b.i.d., then 90 mg 3–4 times daily as needed to normalize calcium concentrations |
Administration
Oral- Give with food or shortly after a meal.
- Tablets should be swallowed whole and not divided, crushed, or chewed.
- Store at 15°–30° C (59°–86° F).
Adverse Effects (≥1%)
Body as a Whole: Dizziness, asthenia, non-cardiac chest pain, dialysis access infection. CV: Hypertension. GI: Nausea, vomiting, diarrhea, anorexia. Metabolic: Hypocalcemia. Musculoskeletal: Myalgia, adynamic bone disease (renal osteodystrophy).Interactions
Drug: May increase amoxapine, atomoxetine, carvedilol, metoprolol, propranolol, timolol, encainide, flecainide, mexiletine, propafenone, clozapine, codeine, cyclobenzaprine, fenfluramine, dexfenfluramine, dextromethorphan, donepezil, fluoxetine, haloperidol, hydrocodone, maprotiline, meperidine, methadone, methamphetamine, morphine, oxycodone, paroxetine, perphenazine, risperidone, thioridazine (use may be contraindicated with cinacalcet), tramadol, trazodone, tricyclic antidepressants, venlafaxine, zolpidem levels; cinacalcet levels may be increased by strong CYP3A4 inhibitors such as fluconazole, itraconazole, ketoconazole, miconazole, voriconazole, clarithromycin, erythromycin, dalfopristin; quinupristin, troleandomycin, verapamil, diltiazem, amiodarone, aprepitant, fluvoxamine, nefazodone, zafirlukast, zileuton. Food: Grapefruit juice may increase cinacalcet levels.Pharmacokinetics
Peak: 2–6 h. Distribution: 93–97% protein bound. Metabolism: In liver by CYP3A4. Elimination: 80% by kidneys, 15% in feces. Half-Life: 30–40 h.Nursing Implications
Assessment & Drug Effects
- Monitor for S&S of hypocalcemia (e.g., paresthesias, myalgias, cramping, tetany, convulsions).
- Withhold drug and notify physician for serum calcium <7.5 mg/dL or symptoms of hypocalcemia. Drug should not be resumed until serum calcium levels reach 8.0 mg/dL, and/or symptoms of hypocalcemia resolve.
- Lab tests: Serum calcium and phosphorus within 1 wk after and iPTH 1–4 wk after initiation of drug or dose adjustment; thereafter, monthly serum calcium and phosphorus (more often with a history of a seizure disorder), and iPTH every 1–3 mo.
- Closely monitor iPTH and serum calcium with concurrent administration of a strong CYP3A4 (e.g., ketoconazole, erythromycin, itraconazole).
Patient & Family Education
- Report promptly any of the following: seizure or convulsion; muscle spasms or cramping of the abdomen, back, legs, face; burning, numbness, pricking, tickling, or tingling of the face, lips, tongue, hands, or feet; changes in mental status.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug