[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Calcimimetics](https://durgical.com/en/pharmacology/classes/calcimimetics/) › Cinacalcet # Cinacalcet ## Calcimimetics? Calcimimetics An oral calcimimetic that lowers PTH and calcium in dialysis patients with secondary hyperparathyroidism and in parathyroid cancer. Updated Nov 1, 2026 ## Quick facts **Group** [Calcimimetics](https://durgical.com/en/pharmacology/classes/calcimimetics/) **Target** Calcium-sensing receptor (CaSR), a G-protein–coupled receptor of the parathyroid gland **Used for** Secondary hyperparathyroidism · Hypercalcaemia **Key effects** Nausea and vomiting · Diarrhoea · Dizziness **Monitor** Serum calcium within a week · Intact PTH · Phosphate **ATC** H05BX01 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ◎**Calcium-sensing receptor (CaSR), a G-protein–coupled receptor of the parathyroid gland**Cinacalcet ⓘ The figure shows cinacalcet itself in the transmembrane domain of the human calcium-sensing receptor (cryo-EM). **Target in 3D:** Calcium-sensing receptor (CaSR), a G-protein–coupled receptor of the parathyroid gland. PDB structure 8WPG (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/8WPG) · Drag to rotate · pinch to zoom Cinacalcet binds the transmembrane part of the calcium-sensing receptor on parathyroid chief cells and makes it more sensitive to extracellular calcium. The gland responds as if calcium were higher and secretes less PTH. Lower PTH reduces bone resorption and renal calcium reabsorption, so serum calcium and the calcium-phosphate product fall. - Cinacalcet binds the calcium-sensing receptor of the parathyroid - The receptor now responds to lower calcium - Chief cells release less PTH - PTH, calcium and the calcium-phosphate product fall ## Indications - Secondary hyperparathyroidism in adults with chronic kidney disease on dialysis [CKD-mineral and bone disorder (renal osteodystrophy) →](https://durgical.com/en/conditions/ckd-mineral-and-bone-disorder/) - Hypercalcaemia in parathyroid carcinoma - Hypercalcaemia in primary hyperparathyroidism when parathyroidectomy is not possible [Primary hyperparathyroidism →](https://durgical.com/en/conditions/primary-hyperparathyroidism/) ## Adverse effects ### Common - Nausea and vomiting - Diarrhoea - Dizziness - Weakness - Chest pain ### Serious (rare, important) - Hypocalcaemia: tingling, cramps, tetany, seizures - QT prolongation and ventricular arrhythmias with low calcium - Worsening heart failure and hypotension - Upper gastrointestinal bleeding - Adynamic bone disease if PTH falls too low ## Contraindications - Starting it when serum calcium is below the lower limit of normal ## Key interactions **Drugs metabolised by CYP2D6 with a narrow margin (flecainide, most tricyclic antidepressants, some beta-blockers)** Cinacalcet inhibits CYP2D6 strongly and raises their levels **Strong CYP3A4 inhibitors (ketoconazole)** Higher cinacalcet levels **Other drugs that lower calcium (e.g. denosumab)** More risk of hypocalcaemia ## What is monitored - Serum calcium within a week of starting or changing the dose, then regularly - Intact PTH, measured at least 12 hours after a dose - Phosphate - ECG/QT in people at risk - Signs of gastrointestinal bleeding; seizures in people with epilepsy ## Administration and safety - Oral tablet once a day, with food or shortly after a meal - Swallowed whole, not split, chewed or crushed - Not started if calcium is below normal; often combined with vitamin D sterols and phosphate binders ## Pregnancy and breastfeeding Human data are limited; it is used in pregnancy only if the benefit justifies the risk. ## Nursing care - Check calcium before the dose; hold and report if it is low - Teach signs of low calcium: tingling of lips or fingers, cramps, muscle spasms - Ask about seizures, heart failure and long QT before starting - Ask about vomiting blood or black stools - Review other drugs for CYP2D6 interactions ## Pharmacokinetics **Absorption** Oral; food, especially a high-fat meal, increases absorption **Metabolism** In the liver by CYP3A4, CYP2D6 and CYP1A2; it is itself a strong CYP2D6 inhibitor **Half-life** Terminal half-life of about 30 to 40 hours, allowing once-daily use ## Memory aid CINACALcet = «CINeA CALcium»: it makes the gland watch a calcium movie, so PTH goes quiet. ## Test yourself Think of the answer, then tap the question to see it. ## Why must cinacalcet be taken with food? Food, especially fat, increases its absorption; the label tells it to be taken with or shortly after a meal. ## When is intact PTH measured in a person on cinacalcet? At least 12 hours after a dose. ## A patient on cinacalcet also takes flecainide. What is the concern? Cinacalcet strongly inhibits CYP2D6, so flecainide levels rise and toxicity becomes more likely. ## What is the contraindication to starting cinacalcet? A serum calcium below the lower limit of normal. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/cinacalcet/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Connections ## Related drugs 2 - [Sevelamer](https://durgical.com/en/pharmacology/sevelamer/) - [Lanthanum carbonate](https://durgical.com/en/pharmacology/lanthanum-carbonate/) ## Related conditions 2 - [CKD-mineral and bone disorder (renal osteodystrophy)](https://durgical.com/en/conditions/ckd-mineral-and-bone-disorder/) - [Primary hyperparathyroidism](https://durgical.com/en/conditions/primary-hyperparathyroidism/) [← Back to the class: Calcimimetics](https://durgical.com/en/pharmacology/classes/calcimimetics/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - CINACALCET tablet](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=02b8c11b-99e8-4039-b6fa-a9c38d2f48fa) (DailyMed (U.S. National Library of Medicine), 2026); [Cinacalcet: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a605004.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=H05BX01) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/cinacalcet/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/cinacalcet/