Zemplar 5mcg/ml Inj, 2ml
It is used to treat or prevent high parathyroid hormone levels in certain patients.
Drug Class
Vitamin D Analog
Pharmacologic Class
Selective Vitamin D Receptor Activator (VDRA)
Pregnancy Category
Category C
FDA Approved
Dec 1998
DEA Schedule
Not Controlled
Overview
What is this medicine?
Paricalcitol is a man-made form of vitamin D that helps control the levels of parathyroid hormone (PTH) in your body. High PTH levels can be a problem for people with kidney disease. This medication helps lower PTH, which can improve bone health and other issues related to kidney disease.
How to Use This Medicine
To use this medication correctly, follow your doctor's instructions and carefully read all accompanying information. Adhere to the guidelines provided to ensure safe and effective use. This medication is administered via intravenous injection.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor promptly to receive guidance on the appropriate course of action.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor promptly to receive guidance on the appropriate course of action.
Lifestyle & Tips
- Follow your doctor's instructions regarding diet, especially limiting foods high in calcium and phosphorus.
- Do not take any other vitamin D supplements, calcium supplements, or antacids containing calcium without consulting your doctor.
- Attend all scheduled blood tests to monitor your calcium, phosphorus, and PTH levels.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial dose is based on baseline intact parathyroid hormone (iPTH) levels. Administered as an IV bolus 3 times per week, no more frequently than every other day. Initial dose (mcg) = baseline iPTH (pg/mL) / 80. Doses are adjusted based on serum iPTH, calcium, and phosphorus levels.
Dose Range:
0.04 - 0.1 mg
Condition-Specific Dosing:
Secondary Hyperparathyroidism in CKD Stage 5 (on dialysis):
Initial dose (mcg) = baseline iPTH (pg/mL) / 80. Administer 3 times per week. Dose adjustments are made in increments of 2 to 4 mcg based on iPTH, calcium, and phosphorus levels to maintain iPTH within target range (150-300 pg/mL) and prevent hypercalcemia/hyperphosphatemia. Maximum dose typically 32 mcg 3 times/week.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment beyond standard iPTH-guided dosing for CKD.
Moderate:
No specific adjustment beyond standard iPTH-guided dosing for CKD.
Severe:
Used in patients with CKD Stage 5 (on dialysis). Dosing is based on iPTH levels as described for adults.
Dialysis:
Administer after hemodialysis sessions.
Hepatic Impairment:
Mild:
No specific dose adjustment recommended.
Moderate:
No specific dose adjustment recommended, but caution advised due to potential for increased exposure.
Severe:
No specific dose adjustment recommended, but caution advised due to potential for increased exposure.
Pharmacology
Mechanism of Action
Paricalcitol is a synthetic analog of calcitriol, the active form of vitamin D. It selectively activates the vitamin D receptor (VDR) in various tissues, including the parathyroid glands. Activation of VDR in the parathyroid glands directly suppresses parathyroid hormone (PTH) synthesis and secretion, thereby reducing elevated PTH levels in patients with chronic kidney disease (CKD). Unlike calcitriol, paricalcitol has a more selective action on the parathyroid glands with less effect on intestinal calcium and phosphorus absorption at therapeutic doses, thus reducing the risk of hypercalcemia and hyperphosphatemia.
Pharmacokinetics
Absorption:
Bioavailability:
100% (IV administration)
Tmax:
Immediate (IV administration)
FoodEffect:
Not applicable (IV administration)
Distribution:
Vd:
Approximately 0.6 L/kg
ProteinBinding:
Greater than 99%
CnssPenetration:
Limited
Elimination:
HalfLife:
Approximately 4-7 hours (terminal half-life)
Clearance:
Not precisely quantified, but primarily hepatic/biliary clearance.
ExcretionRoute:
Approximately 70% via feces (biliary excretion) and 30% via urine.
Unchanged:
Less than 2% of the administered dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Immediate (PTH suppression begins shortly after administration)
PeakEffect:
Within hours for PTH suppression; sustained effect with regular dosing.
DurationOfAction:
Related to half-life and continued PTH suppression, typically lasts for several days after a single dose, allowing for 3 times/week dosing.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high calcium levels, including:
+ Weakness
+ Confusion
+ Fatigue
+ Headache
+ Upset stomach and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in vision
Abnormal heartbeat
Seizures
Increased urination
Weight loss
Decreased appetite
Excessive thirst
Swelling
Vomiting blood or coffee ground-like material
Black, tarry, or bloody stools
Fever or chills
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Diarrhea
Upset stomach or vomiting
Dizziness or headache
Nose or throat irritation
Sleep disturbances
Joint pain
Eye redness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high calcium levels, including:
+ Weakness
+ Confusion
+ Fatigue
+ Headache
+ Upset stomach and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in vision
Abnormal heartbeat
Seizures
Increased urination
Weight loss
Decreased appetite
Excessive thirst
Swelling
Vomiting blood or coffee ground-like material
Black, tarry, or bloody stools
Fever or chills
Other Possible Side Effects
Like all medications, this drug can cause side effects. Many people experience no side effects or only mild ones. If you notice any of the following side effects or any other unusual symptoms, contact your doctor for advice:
Diarrhea
Upset stomach or vomiting
Dizziness or headache
Nose or throat irritation
Sleep disturbances
Joint pain
Eye redness
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Signs of too much calcium (hypercalcemia): Feeling sick to your stomach (nausea, vomiting), constipation, loss of appetite, feeling very tired or weak, muscle weakness, confusion, increased thirst, or urinating more often.
- Signs of too much phosphorus (hyperphosphatemia): Itching, bone pain, or joint pain.
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
Certain health conditions, including high calcium levels or high vitamin D levels.
* If you are breastfeeding, as you should not breastfeed while taking this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced.
Certain health conditions, including high calcium levels or high vitamin D levels.
* If you are breastfeeding, as you should not breastfeed while taking this medication.
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist. They will help determine if it is safe to take this medication with your other medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Regular blood tests will be necessary, as directed by your doctor, to monitor your condition. Be sure to discuss any concerns or questions with your doctor.
If you are currently taking other supplements that contain vitamin D, consult with your doctor to avoid excessive intake. Additionally, if you are using products that contain aluminum, such as certain antacids, inform your doctor to minimize potential interactions.
Consuming grapefruit or grapefruit juice regularly may interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of this medication, adhere to the dietary plan recommended by your doctor.
If you are pregnant or planning to become pregnant, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of continuing this medication during pregnancy to ensure the best possible outcome for you and your baby.
If you are currently taking other supplements that contain vitamin D, consult with your doctor to avoid excessive intake. Additionally, if you are using products that contain aluminum, such as certain antacids, inform your doctor to minimize potential interactions.
Consuming grapefruit or grapefruit juice regularly may interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of this medication, adhere to the dietary plan recommended by your doctor.
If you are pregnant or planning to become pregnant, notify your doctor immediately. You and your doctor will need to carefully weigh the benefits and risks of continuing this medication during pregnancy to ensure the best possible outcome for you and your baby.
Overdose Information
Overdose Symptoms:
- Hypercalcemia (severe nausea, vomiting, constipation, muscle weakness, confusion, coma)
- Hyperphosphatemia
- Hypercalciuria
What to Do:
Immediately contact your doctor or go to an emergency room. Treatment involves discontinuing paricalcitol, hydration, and potentially diuretics or corticosteroids. Call 1-800-222-1222 for Poison Control.
Drug Interactions
Major Interactions
- Ketoconazole (and other strong CYP3A4 inhibitors): May significantly increase paricalcitol exposure, increasing risk of hypercalcemia and hyperphosphatemia. Co-administration should be avoided or paricalcitol dose significantly reduced and calcium/phosphorus monitored closely.
- Digitalis glycosides: Hypercalcemia, a potential adverse effect of paricalcitol, can potentiate the toxicity of digitalis.
Moderate Interactions
- Calcium-containing phosphate binders: Increased risk of hypercalcemia and hyperphosphatemia.
- Other vitamin D analogs or vitamin D supplements: Increased risk of hypercalcemia and hyperphosphatemia.
- Thiazide diuretics: May increase the risk of hypercalcemia.
Monitoring
Baseline Monitoring
Serum intact Parathyroid Hormone (iPTH)
Rationale: To establish baseline and guide initial dosing.
Timing: Prior to initiation of therapy.
Serum Calcium
Rationale: To establish baseline and monitor for hypercalcemia.
Timing: Prior to initiation of therapy.
Serum Phosphorus
Rationale: To establish baseline and monitor for hyperphosphatemia.
Timing: Prior to initiation of therapy.
Serum Alkaline Phosphatase
Rationale: To assess bone turnover.
Timing: Prior to initiation of therapy.
Routine Monitoring
Serum Calcium
Frequency: At least twice weekly during initial dose titration, then weekly for 4 weeks, then monthly once stable.
Target: Within normal limits (e.g., 8.4-10.2 mg/dL), avoiding hypercalcemia.
Action Threshold: If corrected serum calcium > 10.5 mg/dL, reduce or interrupt paricalcitol dose.
Serum Phosphorus
Frequency: At least twice weekly during initial dose titration, then weekly for 4 weeks, then monthly once stable.
Target: Within normal limits (e.g., 2.5-4.5 mg/dL), avoiding hyperphosphatemia.
Action Threshold: If serum phosphorus > 5.5 mg/dL, reduce or interrupt paricalcitol dose and/or adjust phosphate binder regimen.
Serum intact Parathyroid Hormone (iPTH)
Frequency: Every 2-4 weeks during initial dose titration, then every 1-3 months once stable.
Target: 150-300 pg/mL (KDOQI guidelines for CKD Stage 5D).
Action Threshold: Adjust dose to maintain iPTH within target range; if iPTH falls below target, reduce or interrupt dose.
Symptom Monitoring
- Symptoms of hypercalcemia: Nausea, vomiting, constipation, anorexia, muscle weakness, fatigue, confusion, polyuria, polydipsia.
- Symptoms of hyperphosphatemia: Pruritus, bone pain, soft tissue calcification.
Special Patient Groups
Pregnancy
Category C. There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies have shown adverse effects on fetal development at doses higher than human therapeutic doses.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm based on animal data.
Second Trimester:
Potential for fetal harm based on animal data.
Third Trimester:
Potential for fetal harm based on animal data.
Lactation
It is not known whether paricalcitol is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from paricalcitol, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
Unknown; potential for hypercalcemia in infant.
Pediatric Use
Safety and efficacy have not been established in pediatric patients. Use is not recommended.
Geriatric Use
No overall differences in safety or effectiveness have been observed between elderly and younger patients. However, due to the higher likelihood of decreased renal, hepatic, or cardiac function, and concomitant disease or other drug therapy in elderly patients, dose selection should be cautious, and monitoring should be close.
Clinical Information
Clinical Pearls
- Administer paricalcitol injection after hemodialysis sessions to ensure accurate post-dialysis blood levels for monitoring.
- The goal of therapy is to maintain iPTH levels within the target range (e.g., 150-300 pg/mL for CKD Stage 5D) while avoiding hypercalcemia and hyperphosphatemia.
- Careful and frequent monitoring of serum calcium, phosphorus, and iPTH is crucial, especially during dose titration.
- Avoid concomitant use of calcium-containing phosphate binders, other vitamin D analogs, or large doses of calcium supplements unless specifically directed by a physician, due to increased risk of hypercalcemia/hyperphosphatemia.
- Patients should be advised to report any symptoms of hypercalcemia promptly.
Alternative Therapies
- Calcitriol (Rocaltrol, Calcijex)
- Doxercalciferol (Hectorol)
- Cinacalcet (Sensipar) - a calcimimetic, not a VDRA, but used for similar indication.
Cost & Coverage
Average Cost:
Varies significantly by dose and pharmacy per 2ml vial (5mcg/ml)
Generic Available:
Yes
Insurance Coverage:
Typically covered by Medicare Part D and most commercial insurance plans, often as a Tier 3 or specialty drug. Prior authorization may be required.
General Drug Facts
If your symptoms or health problems do not improve or worsen over time, it is essential to contact your doctor for further evaluation and guidance. To ensure safe use, never share your medication with others, and do not take medication prescribed for someone else. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion. Dispose of unused or expired medications properly. Unless instructed to do so by a healthcare professional or pharmacist, avoid flushing medications down the toilet or pouring them down the drain. If you are unsure about the proper disposal method, consult your pharmacist, as they can provide guidance on disposal procedures and potential drug take-back programs in your area. Some medications may come with an additional patient information leaflet; check with your pharmacist for more information. If you have any questions or concerns about your medication, discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide information about the medication taken, the amount, and the time it was taken to ensure prompt and effective treatment.