Parsabiv (Etelcalcetide)
Calcimimetic agent for secondary hyperparathyroidism in hemodialysis patients
Quick Facts About Parsabiv
Key Takeaways About Parsabiv
- Administered at dialysis: Parsabiv is given intravenously at the end of hemodialysis sessions by a healthcare professional, ensuring full treatment adherence
- Effective PTH reduction: Clinical trials demonstrated that Parsabiv significantly reduces PTH levels, with over 70% of patients achieving greater than 30% PTH reduction
- Monitor calcium closely: Hypocalcemia is a significant risk; serum calcium must be checked before starting and within one week of any dose change
- Do not combine with cinacalcet: Concurrent use with cinacalcet is contraindicated due to the risk of severe hypocalcemia
- Dose range 2.5–15 mg: The starting dose is 5 mg three times per week, with titration based on PTH and calcium levels
What Is Parsabiv and What Is It Used For?
Parsabiv (etelcalcetide) is a calcimimetic agent indicated for the treatment of secondary hyperparathyroidism (SHPT) in adults with chronic kidney disease (CKD) who are receiving hemodialysis. It lowers elevated parathyroid hormone (PTH) levels by activating the calcium-sensing receptor on parathyroid gland cells.
Secondary hyperparathyroidism is a common and serious complication of chronic kidney disease, particularly in patients requiring dialysis. When the kidneys lose their ability to adequately regulate calcium and phosphorus levels, the parathyroid glands respond by producing excessive amounts of parathyroid hormone. This hormonal excess triggers a cascade of metabolic disturbances that can affect multiple organ systems throughout the body.
The parathyroid glands are four small endocrine glands located behind the thyroid gland in the neck. Their primary function is to regulate calcium homeostasis by secreting PTH, which acts on bone, kidneys, and the intestines. In patients with CKD, the dysregulation of mineral metabolism leads to a condition known as CKD-Mineral and Bone Disorder (CKD-MBD), which encompasses abnormalities in calcium, phosphorus, PTH, and vitamin D metabolism.
Parsabiv contains the active substance etelcalcetide, a synthetic peptide that acts as a calcimimetic agent. Unlike cinacalcet, which is an oral calcimimetic, etelcalcetide is designed specifically for intravenous administration at the end of hemodialysis sessions. This route of administration ensures complete bioavailability and eliminates concerns about gastrointestinal absorption or patient adherence to daily oral medication.
The clinical significance of treating SHPT cannot be overstated. Uncontrolled SHPT leads to progressive bone demineralization, vascular and soft tissue calcification, cardiovascular complications, increased fracture risk, and ultimately increased morbidity and mortality. The KDIGO (Kidney Disease: Improving Global Outcomes) guidelines recommend maintaining PTH levels within a target range to minimize these complications.
Etelcalcetide binds to and activates the calcium-sensing receptor (CaSR) on the surface of chief cells in the parathyroid glands. By mimicking the action of calcium at these receptors, it signals the parathyroid glands to reduce PTH secretion. This mechanism is why drugs in this class are called "calcimimetics" – they mimic calcium's regulatory effect on the parathyroid gland without actually raising serum calcium levels.
What Should You Know Before Receiving Parsabiv?
Before starting Parsabiv, your healthcare provider must verify that your corrected serum calcium is not below the lower limit of normal. Parsabiv should not be used if you are allergic to etelcalcetide, and certain conditions such as heart failure, arrhythmias, or seizure history require special consideration.
Contraindications
Parsabiv must not be used in the following situations:
- Hypersensitivity: Known allergy to etelcalcetide or any of the excipients (sodium chloride, succinic acid, water for injections, hydrochloric acid, sodium hydroxide)
- Hypocalcemia: Corrected serum calcium below the lower limit of normal. Your physician will check calcium levels before initiating treatment
These contraindications are absolute, meaning that Parsabiv must not be administered under these circumstances regardless of the potential benefit of treating SHPT. The risk of worsening hypocalcemia in patients who already have low calcium levels can lead to life-threatening complications including cardiac arrhythmias and seizures.
Warnings and Precautions
Before starting Parsabiv, inform your healthcare provider if you have or have ever had:
- Heart problems: Heart failure or cardiac arrhythmias (abnormal heart rhythm). Low calcium levels caused by Parsabiv can prolong the QT interval on an electrocardiogram (ECG), which may lead to dangerous arrhythmias
- Seizure history: A history of seizures or epilepsy. Hypocalcemia lowers the seizure threshold and may increase the risk of convulsions
Parsabiv lowers calcium levels in the blood. Contact your healthcare provider immediately if you experience muscle spasms, twitching or cramping, numbness or tingling in your fingers, toes, or around the mouth, seizures, confusion, or loss of consciousness. These may be signs of dangerously low calcium levels. Severe hypocalcemia can cause QT prolongation, ventricular arrhythmias, and cardiac arrest.
Very low PTH levels maintained over prolonged periods can lead to adynamic bone disease, a condition characterized by reduced bone turnover. This form of bone disease can only be definitively diagnosed through bone biopsy. Your healthcare provider will monitor your PTH levels throughout treatment and may reduce the Parsabiv dose if PTH levels fall too low, typically below approximately two times the lower limit of normal for the assay.
Pregnancy and Breastfeeding
Parsabiv has not been studied in pregnant women. It is unknown whether etelcalcetide can harm an unborn child. As a precautionary measure, Parsabiv should be avoided during pregnancy. Women of childbearing potential should discuss contraception with their healthcare provider.
It is not known whether etelcalcetide passes into breast milk. A decision must be made whether to discontinue breastfeeding or discontinue Parsabiv therapy, taking into account the benefit of breastfeeding for the child and the benefit of Parsabiv for the mother. Your healthcare provider will help you make this decision.
Children and Adolescents
The safety and efficacy of Parsabiv have not been established in children and adolescents under 18 years of age. No data are available in this population, and Parsabiv should not be used in pediatric patients until further studies are conducted.
Driving and Operating Machinery
Parsabiv has no or negligible direct effect on the ability to drive and use machines. However, certain symptoms of hypocalcemia, such as seizures, dizziness, or muscle spasms, can impair the ability to drive or operate machinery safely. Patients should be advised to exercise caution if they experience these symptoms.
Sodium Content
Parsabiv contains less than 1 mmol (23 mg) sodium per vial, meaning it is essentially sodium-free. This is relevant for patients on a sodium-restricted diet.
How Does Parsabiv Interact with Other Drugs?
Parsabiv must not be used together with cinacalcet. It should be used with caution alongside other medications that lower calcium levels, such as denosumab. Always inform your healthcare provider about all medications you are taking.
Drug interactions are an important consideration for patients receiving Parsabiv, as many hemodialysis patients take multiple medications simultaneously. The potential for pharmacodynamic interactions – where two drugs have additive or synergistic effects on the same physiological pathway – is of particular concern with calcimimetic agents.
Major Interactions
| Drug | Interaction | Clinical Significance |
|---|---|---|
| Cinacalcet (Sensipar/Mimpara) | Both are calcimimetic agents that reduce PTH and calcium; additive hypocalcemic effect | Contraindicated – do not use together. Discontinue cinacalcet before starting Parsabiv |
| Denosumab (Prolia/Xgeva) | Denosumab also lowers serum calcium; combined use increases hypocalcemia risk | Use with caution; intensify calcium monitoring if co-administered |
Minor Interactions and Considerations
While formal drug-drug interaction studies with Parsabiv are limited, clinicians should be aware of the following pharmacodynamic considerations in the context of hemodialysis patients:
| Drug / Class | Consideration | Recommendation |
|---|---|---|
| QT-prolonging drugs | Hypocalcemia from Parsabiv may potentiate QT prolongation | Monitor ECG and calcium levels closely |
| Calcium supplements | May be needed to manage Parsabiv-induced hypocalcemia | Adjust doses as directed by healthcare provider |
| Vitamin D analogues | Often co-prescribed; may help maintain calcium levels | Dose adjustments may be necessary during Parsabiv titration |
| Phosphate binders | Commonly used in dialysis patients; calcium-based binders contribute to calcium intake | Consider switching to or adding calcium-based binders if calcium levels drop |
Etelcalcetide is a peptide that is cleared primarily through hemodialysis. It does not undergo hepatic metabolism through cytochrome P450 enzymes, which reduces the likelihood of traditional pharmacokinetic drug interactions. However, as noted above, pharmacodynamic interactions with other calcium-lowering agents remain the primary concern.
What Is the Correct Dosage of Parsabiv?
The recommended starting dose of Parsabiv is 5 mg administered intravenously three times per week at the end of hemodialysis. The dose can be titrated between 2.5 mg and 15 mg based on PTH response and calcium levels. Parsabiv is always administered by a healthcare professional.
Parsabiv dosing requires careful individualization based on each patient's PTH levels, calcium levels, and clinical response. Unlike many other medications, Parsabiv is not self-administered – it is given by healthcare professionals at the dialysis center, which ensures proper dosing and monitoring.
Adults
Standard Dosing Protocol
- Starting dose: 5 mg administered intravenously three times per week at the end of hemodialysis
- Administration route: Through the venous line of the dialysis circuit after rinsing
- Dose titration: May be increased in increments of 2.5 mg or 5 mg no more frequently than every 4 weeks, based on PTH and calcium response
- Maximum dose: 15 mg three times per week
- Minimum dose: 2.5 mg three times per week
| Clinical Scenario | PTH Level | Calcium Level | Action |
|---|---|---|---|
| PTH above target | Above target range | Within normal limits | Increase dose by 2.5–5 mg (max 15 mg) |
| PTH at target | Within target range | Within normal limits | Maintain current dose |
| PTH below target | Below target range | Within normal limits | Reduce dose or temporarily withhold |
| Hypocalcemia developing | Any level | Below normal, ≥7.5 mg/dL | Reduce dose; increase calcium and vitamin D supplements |
| Severe hypocalcemia | Any level | Below 7.5 mg/dL or symptoms present | Withhold Parsabiv; administer calcium; reassess |
Children
Parsabiv has not been studied in patients under 18 years of age. There are no dosing recommendations for pediatric patients. The safety and efficacy of etelcalcetide in children and adolescents have not been established.
Elderly
No dose adjustment is required based on age alone. However, elderly patients may be more susceptible to hypocalcemia and its cardiovascular consequences, including QT prolongation and cardiac arrhythmias. More frequent monitoring of serum calcium and cardiac status may be warranted in older patients. Clinical trial data included patients aged 65 years and older, and no overall differences in safety or efficacy were observed compared to younger patients.
Missed Dose
Since Parsabiv is administered by healthcare professionals at dialysis sessions, missed doses typically occur only when a patient misses a dialysis appointment. If a dose is missed, it should be given at the next scheduled dialysis session. Do not double the dose to make up for a missed one. If multiple doses are missed, the physician may need to reassess the dosing regimen and restart at a lower dose with calcium monitoring.
Overdose
In the event of overdose, hypocalcemia is the primary concern. Patients should be monitored for signs and symptoms of hypocalcemia, including muscle spasms, numbness, tingling, and cardiac arrhythmias. Treatment is supportive and includes intravenous calcium gluconate or calcium chloride as needed. Since etelcalcetide is removed by dialysis, hemodialysis can be used to reduce drug levels. There is no specific antidote for etelcalcetide overdose.
Many patients receiving Parsabiv will need supplemental calcium and vitamin D to prevent or treat hypocalcemia. Your healthcare provider will advise you on the appropriate type and dose of supplements. Calcium-based phosphate binders, active vitamin D analogues (such as calcitriol or paricalcitol), and calcium supplements may all be adjusted during Parsabiv therapy. The dialysate calcium concentration may also be increased to 3.0 mEq/L or higher.
What Are the Side Effects of Parsabiv?
The most common side effects of Parsabiv include nausea, vomiting, diarrhea, muscle spasms, and decreased blood calcium levels (hypocalcemia). Most gastrointestinal side effects are transient and tend to occur around the time of injection. Serious side effects include symptomatic hypocalcemia, which can cause cardiac complications.
Like all medicines, Parsabiv can cause side effects, although not everyone experiences them. The side effect profile of etelcalcetide has been well characterized through multiple phase III clinical trials involving over 1,000 patients. Understanding the frequency and nature of side effects helps patients and healthcare providers make informed treatment decisions.
The most clinically significant side effect is hypocalcemia (low blood calcium), which underlies many of the symptoms reported during treatment. Gastrointestinal symptoms – nausea, vomiting, and diarrhea – are the most frequently reported adverse effects and tend to be more common in the first few weeks of treatment. In clinical trials, these symptoms were generally mild to moderate in severity and often resolved without discontinuation of therapy.
Very Common
- Nausea
- Vomiting
- Diarrhea
- Muscle spasms
- Decreased blood calcium (hypocalcemia) without symptoms
Common
- High potassium levels in the blood (hyperkalemia)
- Low phosphate levels in the blood (hypophosphatemia)
- Headache
- Numbness or tingling sensation (paresthesia)
- Worsening heart failure
- QT prolongation on ECG
- Low blood pressure (hypotension)
- Muscle pain (myalgia)
Uncommon
- Seizures (convulsions)
Frequency Not Known
- Allergic reactions (including anaphylaxis)
Contact your healthcare provider or seek emergency medical attention if you experience: numbness or tingling around the mouth or in your arms and legs, severe muscle pain or cramps, seizures or convulsions, unusually rapid or pounding heartbeat, chest pain, difficulty breathing, severe dizziness or fainting, or signs of a severe allergic reaction (swelling of face, lips, tongue, or throat; difficulty breathing; rash or hives).
In the pivotal phase III clinical trials, the discontinuation rate due to adverse events was approximately 8-10% in the etelcalcetide group compared to 6-8% in the placebo group. The most common reasons for discontinuation were hypocalcemia and gastrointestinal adverse events. Notably, in head-to-head comparison studies with cinacalcet, etelcalcetide demonstrated a similar overall safety profile but with less frequent gastrointestinal side effects on a per-dose basis.
Healthcare providers managing patients on Parsabiv should regularly monitor serum calcium levels (within 1 week of initiation or dose adjustment, and then at regular intervals), PTH levels (every 1 to 4 weeks), and phosphorus levels. Symptoms of hypocalcemia should be actively queried at each dialysis session, and patients should be educated about the signs and symptoms to watch for between sessions.
How Should Parsabiv Be Stored?
Parsabiv should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light. Once removed from refrigeration, it may be kept for up to 7 days in the carton, or up to 4 hours outside the carton if protected from direct sunlight.
Proper storage of Parsabiv is essential to maintain the drug's stability and efficacy. As a biological peptide product, etelcalcetide is sensitive to temperature fluctuations and light exposure. The following storage conditions should be observed:
- Refrigerated storage: Store at 2°C to 8°C (36°F to 46°F) in the original outer carton to protect from light
- Out of refrigerator (in carton): Stable for a total of up to 7 days when kept in the original carton. No special temperature requirements
- Out of carton: Stable for up to 4 hours when protected from direct sunlight
- Single use only: Each vial is for single use. Discard any unused portion
- Visual inspection: Do not use if the solution contains particles or if the color has changed. The solution should be clear and colorless
- Expiry date: Do not use after the expiration date printed on the carton (EXP). The expiry date refers to the last day of that month
Keep all medicines out of the sight and reach of children. Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures help protect the environment.
What Does Parsabiv Contain?
Parsabiv contains etelcalcetide as the active substance at a concentration of 5 mg/mL. It is available in three vial sizes: 2.5 mg (0.5 mL), 5 mg (1 mL), and 10 mg (2 mL). Inactive ingredients include sodium chloride, succinic acid, water for injections, hydrochloric acid, and sodium hydroxide.
Active Substance
The active ingredient is etelcalcetide, a synthetic D-amino acid peptide consisting of a linear chain of seven amino acids linked via a disulfide bond to an L-cysteine residue. This unique molecular structure allows it to bind to the calcium-sensing receptor on parathyroid cells with high specificity and affinity.
| Strength | Volume per Vial | Concentration |
|---|---|---|
| 2.5 mg | 0.5 mL | 5 mg/mL |
| 5 mg | 1 mL | 5 mg/mL |
| 10 mg | 2 mL | 5 mg/mL |
Inactive Ingredients (Excipients)
- Sodium chloride: Used as a tonicity agent to make the solution isotonic
- Succinic acid: Buffer to maintain pH stability
- Water for injections: Solvent
- Hydrochloric acid: pH adjustment
- Sodium hydroxide: pH adjustment
Appearance and Packaging
Parsabiv is a clear, colorless solution for injection in a single-use glass vial. It is available in pack sizes of 1, 6, 12, and 42 vials. Not all pack sizes may be marketed in all countries.
Frequently Asked Questions About Parsabiv
Parsabiv (etelcalcetide) is used to treat secondary hyperparathyroidism (SHPT) in adult patients with chronic kidney disease who are on hemodialysis. It works by lowering parathyroid hormone (PTH) levels, which helps control calcium and phosphorus metabolism. Uncontrolled SHPT can lead to bone disease, vascular calcification, and cardiovascular complications.
Parsabiv is administered as an intravenous (IV) injection by a healthcare professional at the end of each hemodialysis session, typically three times per week. It is given through the venous line of the dialysis circuit. You do not need to self-inject this medication – it is always given at your dialysis center.
No, Parsabiv and cinacalcet (Sensipar/Mimpara) should not be used together. Both medications are calcimimetic agents that lower calcium and PTH levels. Using them concurrently significantly increases the risk of severe hypocalcemia (dangerously low calcium levels). If you are switching from cinacalcet to Parsabiv, your physician will stop cinacalcet before starting Parsabiv.
If you experience symptoms such as muscle cramps, tingling or numbness in your fingers, toes, or around your mouth, unusual tiredness, confusion, or rapid heartbeat between dialysis sessions, contact your healthcare provider promptly. These could be signs of low calcium levels (hypocalcemia), which may require medical attention. Do not wait until your next scheduled dialysis session if symptoms are severe.
Both Parsabiv and cinacalcet are calcimimetic agents used to treat secondary hyperparathyroidism, but they differ in important ways. Parsabiv is given intravenously at the dialysis center (three times per week), while cinacalcet is a daily oral pill taken at home. Clinical trials have shown Parsabiv to be non-inferior and potentially superior to cinacalcet in achieving PTH reduction targets. Parsabiv also has the advantage of guaranteed adherence since it is given by healthcare professionals during dialysis.
Regular blood monitoring is essential during Parsabiv treatment. Serum calcium should be measured before initiation and within 1 week of starting treatment or changing the dose, then periodically. PTH levels are typically checked every 1 to 4 weeks. Phosphorus levels are also monitored. These tests help your healthcare team adjust your dose and ensure the medication is working safely and effectively.
References
This article is based on the following peer-reviewed sources and international guidelines:
- European Medicines Agency (EMA). Parsabiv (etelcalcetide) – Summary of Product Characteristics. Available at: EMA Parsabiv EPAR.
- U.S. Food and Drug Administration (FDA). Parsabiv (etelcalcetide) Prescribing Information. Amgen Inc., 2017.
- Block GA, Bushinsky DA, Cheng S, et al. Effect of Etelcalcetide vs Cinacalcet on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: A Randomized Clinical Trial. JAMA. 2017;317(2):156-164. doi:10.1001/jama.2016.19468.
- Block GA, Bushinsky DA, Cunningham J, et al. Effect of Etelcalcetide vs Placebo on Serum Parathyroid Hormone in Patients Receiving Hemodialysis With Secondary Hyperparathyroidism: Two Randomized Clinical Trials. JAMA. 2017;317(2):146-155. doi:10.1001/jama.2016.19456.
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD-MBD Update Work Group. KDIGO 2024 Clinical Practice Guideline Update for the Prevention, Diagnosis, Evaluation, and Treatment of Chronic Kidney Disease–Mineral and Bone Disorder (CKD-MBD). Kidney International Supplements. 2024.
- World Health Organization (WHO). Model List of Essential Medicines, 23rd List. Geneva: WHO; 2023.
- Hanudel MR, Laster M, Salusky IB. Non-calcemic actions of calcimimetics in chronic kidney disease. Nephrology Dialysis Transplantation. 2022;37(1):12-19.
- British National Formulary (BNF). Etelcalcetide. Available at: bnf.nice.org.uk. Accessed January 2026.
About Our Medical Editorial Team
This article was written, reviewed, and fact-checked by the iMedic Medical Editorial Team, which consists of licensed specialist physicians with expertise in nephrology, clinical pharmacology, and endocrinology. Our team follows the GRADE evidence framework and adheres to international guidelines from KDIGO, EMA, FDA, and WHO.
Medical Writing
Board-certified physicians with specialization in nephrology and clinical pharmacology. All content is based on peer-reviewed research and official prescribing information.
Medical Review
Independent review by the iMedic Medical Review Board, ensuring accuracy, completeness, and adherence to KDIGO, EMA, and FDA guidelines.
All medical content on iMedic is evidence-based (Level 1A), independently funded with no pharmaceutical sponsorship, and regularly updated to reflect the latest clinical guidelines. Read more about our editorial standards and medical team.