Zemplar 2mcg Capsules
It is used to treat or prevent high parathyroid hormone levels in certain patients.
Drug Class
Vitamin D analog; Parathyroid hormone inhibitor
Pharmacologic Class
Selective Vitamin D Receptor Activator (VDRA)
Pregnancy Category
Category C
FDA Approved
Dec 2005
DEA Schedule
Not Controlled
Overview
What is this medicine?
Paricalcitol is a medicine that is a man-made form of vitamin D. It helps to control the levels of parathyroid hormone, calcium, and phosphorus in your body, especially if you have kidney disease and are on dialysis. This helps keep your bones healthy and prevents problems caused by too much parathyroid hormone.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. It's essential to continue taking this medication as directed by your doctor or healthcare provider, even if you're feeling well.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, consult with your pharmacist for guidance on the best disposal method. You may also want to explore local drug take-back programs.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Avoid taking two doses at the same time or taking extra doses. If you take this medication three times a week and miss a dose, contact your doctor for guidance on what to do next.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. It's essential to continue taking this medication as directed by your doctor or healthcare provider, even if you're feeling well.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so. Instead, consult with your pharmacist for guidance on the best disposal method. You may also want to explore local drug take-back programs.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Avoid taking two doses at the same time or taking extra doses. If you take this medication three times a week and miss a dose, contact your doctor for guidance on what to do next.
Lifestyle & Tips
- Follow your doctor's instructions regarding diet, especially limiting phosphorus and calcium intake.
- Do not take calcium supplements or calcium-containing antacids/phosphate binders unless specifically instructed by your doctor.
- Attend all scheduled blood tests to monitor calcium, phosphorus, and PTH levels.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Initial dose based on baseline intact parathyroid hormone (iPTH) levels: If iPTH ⤠500 pg/mL, 1 mcg daily or 2 mcg three times a week. If iPTH > 500 pg/mL, 2 mcg daily or 4 mcg three times a week. Dosing adjusted based on serum calcium, phosphorus, and iPTH levels.
Dose Range:
1 - 8 mg
Condition-Specific Dosing:
secondary hyperparathyroidism in CKD Stage 5:
Initial dose based on iPTH: ⤠500 pg/mL (1 mcg daily or 2 mcg 3x/week); > 500 pg/mL (2 mcg daily or 4 mcg 3x/week). Max dose 10 mcg daily or 20 mcg 3x/week.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (Zemplar injection is approved for pediatric use, but capsules are not)
Adolescent:
Not established (Zemplar injection is approved for pediatric use, but capsules are not)
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment beyond initial PTH-based dosing; monitor calcium and phosphorus closely.
Moderate:
No specific adjustment beyond initial PTH-based dosing; monitor calcium and phosphorus closely.
Severe:
Used in patients with CKD Stage 5; initial dosing is based on iPTH levels. Monitor calcium and phosphorus closely.
Dialysis:
Used in patients on dialysis; initial dosing is based on iPTH levels. Monitor calcium and phosphorus closely.
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 target tissues, including the parathyroid glands. This activation leads to a reduction in parathyroid hormone (PTH) synthesis and secretion without significantly elevating serum calcium or phosphorus levels at therapeutic doses, unlike non-selective vitamin D analogs. It also helps maintain calcium and phosphorus homeostasis.
Pharmacokinetics
Absorption:
Bioavailability:
72%
Tmax:
2-4 hours
FoodEffect:
High-fat meal decreases Cmax and AUC slightly, but not clinically significant; can be taken with or without food.
Distribution:
Vd:
3.1 L/kg
ProteinBinding:
>99%
CnssPenetration:
Limited
Elimination:
HalfLife:
15-30 hours
Clearance:
Not available (primarily hepatic/biliary)
ExcretionRoute:
Primarily biliary/fecal (~70%), with some renal excretion (~30%).
Unchanged:
<2%
Pharmacodynamics
OnsetOfAction:
Days to weeks (for PTH reduction)
PeakEffect:
Weeks to months (for stable PTH reduction)
DurationOfAction:
Dependent on half-life and continued dosing
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency 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
+ Nausea and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in vision
Abnormal heartbeat
Seizures
Frequent 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. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor for guidance:
Diarrhea
Nausea or vomiting
Dizziness or headache
Nasal or throat irritation
Sleep disturbances
Joint pain
Eye redness
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. 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.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency 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
+ Nausea and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache
+ Dizziness
+ Fainting
+ Changes in vision
Abnormal heartbeat
Seizures
Frequent 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. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor for guidance:
Diarrhea
Nausea or vomiting
Dizziness or headache
Nasal or throat irritation
Sleep disturbances
Joint pain
Eye redness
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects not mentioned here. 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:
- Nausea
- Vomiting
- Constipation
- Loss of appetite
- Unusual weakness or tiredness
- Muscle pain or weakness
- Bone pain
- Confusion
- Increased thirst or urination
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 allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including high calcium levels or high vitamin D levels, as these may affect your ability to take this medication safely.
* 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, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your other medications and health conditions.
Remember, do not start, stop, or change the dose of any medication without first consulting your doctor to ensure your safety.
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 allergic reaction you experienced, including any symptoms that occurred.
Certain health conditions, including high calcium levels or high vitamin D levels, as these may affect your ability to take this medication safely.
* 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, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your other medications and health conditions.
Remember, do not start, stop, or change the dose of any medication without first consulting your doctor to ensure your safety.
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 antacids or other products that contain aluminum, inform your doctor, as this may interact with your medication.
Consuming grapefruit juice or eating grapefruit regularly may also interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of your treatment, follow the personalized diet plan recommended by your doctor.
If you are pregnant or planning to become pregnant, consult with your doctor to weigh the benefits and risks of using this medication during pregnancy.
When taking this medication, be aware of potential interactions with other substances. If you are also taking cholestyramine or mineral oil, take this medication at least 1 hour before or 4 to 6 hours after taking cholestyramine or mineral oil to minimize interactions.
If you are currently taking other supplements that contain vitamin D, consult with your doctor to avoid excessive intake. Additionally, if you are using antacids or other products that contain aluminum, inform your doctor, as this may interact with your medication.
Consuming grapefruit juice or eating grapefruit regularly may also interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of your treatment, follow the personalized diet plan recommended by your doctor.
If you are pregnant or planning to become pregnant, consult with your doctor to weigh the benefits and risks of using this medication during pregnancy.
When taking this medication, be aware of potential interactions with other substances. If you are also taking cholestyramine or mineral oil, take this medication at least 1 hour before or 4 to 6 hours after taking cholestyramine or mineral oil to minimize interactions.
Overdose Information
Overdose Symptoms:
- Hypercalcemia (high blood calcium levels): nausea, vomiting, constipation, anorexia, weakness, fatigue, confusion, muscle pain, bone pain, polyuria, polydipsia.
- Hyperphosphatemia (high blood phosphorus levels).
What to Do:
Discontinue paricalcitol, initiate a low-calcium diet, and manage fluid and electrolyte imbalances. Contact a poison control center (1-800-222-1222) or seek immediate medical attention.
Drug Interactions
Major Interactions
- Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin, ritonavir): Significantly increase paricalcitol exposure, requiring dose reduction.
Moderate Interactions
- Phosphate binders (calcium-containing): Increased risk of hypercalcemia.
- Calcium supplements: Increased risk of hypercalcemia.
- Magnesium-containing antacids: Increased risk of hypermagnesemia.
- Digitalis glycosides: Hypercalcemia may potentiate digitalis toxicity.
Monitoring
Baseline Monitoring
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.
Intact Parathyroid Hormone (iPTH)
Rationale: To establish baseline and guide initial dosing.
Timing: Prior to initiation of therapy.
Alkaline Phosphatase
Rationale: To assess bone turnover.
Timing: Prior to initiation of therapy.
Routine Monitoring
Serum Calcium
Frequency: At least twice weekly initially, then weekly for 4 weeks, then monthly.
Target: Normal range (e.g., 8.4-10.2 mg/dL)
Action Threshold: >10.5 mg/dL (consider dose reduction or interruption)
Serum Phosphorus
Frequency: At least twice weekly initially, then weekly for 4 weeks, then monthly.
Target: Normal range (e.g., 2.5-4.5 mg/dL)
Action Threshold: >5.5 mg/dL (consider dose reduction or interruption)
Intact Parathyroid Hormone (iPTH)
Frequency: Every 3 months (or more frequently during dose titration).
Target: 150-300 pg/mL (for CKD Stage 5)
Action Threshold: Outside target range (adjust dose)
Symptom Monitoring
- Symptoms of hypercalcemia (e.g., nausea, vomiting, constipation, anorexia, weakness, fatigue, confusion, muscle pain, bone pain, polyuria, polydipsia)
- Symptoms of hyperphosphatemia (e.g., pruritus, bone pain, vascular calcification)
Special Patient Groups
Pregnancy
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:
Limited human data; animal studies show developmental toxicity.
Second Trimester:
Limited human data; animal studies show developmental toxicity.
Third Trimester:
Limited human data; animal studies show developmental toxicity.
Lactation
It is not known whether paricalcitol is excreted in human milk. Caution should be exercised when paricalcitol is administered to a nursing woman. The decision to discontinue nursing or discontinue the drug should take into account the importance of the drug to the mother.
Infant Risk:
Risk is unknown. Monitor breastfed infants for signs of hypercalcemia (e.g., poor feeding, vomiting, constipation).
Pediatric Use
Safety and efficacy of Zemplar capsules have not been established in pediatric patients. Zemplar injection is approved for pediatric use.
Geriatric Use
No overall differences in safety or effectiveness have been observed between elderly and younger patients. Dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
Clinical Information
Clinical Pearls
- Strict monitoring of serum calcium and phosphorus is crucial, especially during dose initiation and titration, to prevent hypercalcemia and hyperphosphatemia.
- Paricalcitol is a selective VDRA, meaning it aims to suppress PTH with less impact on calcium and phosphorus levels compared to non-selective vitamin D analogs like calcitriol.
- Patients should be educated on the symptoms of hypercalcemia and instructed to report them immediately.
- Avoid concomitant use of high-dose calcium supplements or calcium-containing phosphate binders unless specifically directed by a physician and with very close monitoring.
- Capsules can be taken with or without food.
Alternative Therapies
- Calcitriol (Rocaltrol, Calcijex)
- Doxercalciferol (Hectorol)
- Cinacalcet (Sensipar) - a calcimimetic, not a VDRA, but used for similar indication
- Etelcalcetide (Parsabiv) - a calcimimetic, not a VDRA, but used for similar indication
Cost & Coverage
Average Cost:
Variable, check current pricing per 30 capsules
Generic Available:
Yes
Insurance Coverage:
Tier 2 or 3 (Specialty/Non-Preferred Brand, or Preferred Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.