Paricalcitol 4mcg Capsules
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
Pregnancy Category
C
FDA Approved
Dec 2000
DEA Schedule
Not Controlled
Overview
What is this medicine?
Paricalcitol is a form of vitamin D that helps control the levels of parathyroid hormone (PTH) in your body. It's used to treat a condition called secondary hyperparathyroidism, which often occurs in people with kidney disease. By lowering PTH, it helps keep your calcium and phosphorus levels balanced and protects your bones.
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
- Take paricalcitol exactly as prescribed by your doctor. Do not take more or less than directed.
- Do not take any other vitamin D supplements or calcium supplements unless specifically instructed by your doctor.
- Avoid aluminum-containing antacids (e.g., aluminum hydroxide) while taking paricalcitol, as they can increase aluminum levels and lead to toxicity.
- Follow any dietary restrictions recommended by your doctor or dietitian, especially regarding calcium and phosphorus intake.
- Attend all scheduled blood tests to monitor your calcium, phosphorus, and PTH levels. These tests are crucial for safe and effective treatment.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial dose based on baseline intact parathyroid hormone (iPTH) levels. For CKD Stage 3/4: If iPTH < 500 pg/mL, initial dose 1 mcg daily or 2 mcg three times weekly. If iPTH ≥ 500 pg/mL, initial dose 2 mcg daily or 4 mcg three times weekly. For CKD Stage 5 (dialysis): If iPTH ≤ 500 pg/mL, initial dose 1 mcg daily or 2 mcg three times weekly. If iPTH > 500 pg/mL, initial dose 2 mcg daily or 4 mcg three times weekly. Doses are adjusted in increments of 1-2 mcg every 2-4 weeks to maintain iPTH within target range (150-300 pg/mL for CKD Stage 5) while avoiding hypercalcemia and hyperphosphatemia.
Dose Range:
1 - 10 mg
Condition-Specific Dosing:
CKD Stage 3/4:
Initial dose 1-2 mcg daily or 2-4 mcg three times weekly, adjusted to target iPTH.
CKD Stage 5 (Dialysis):
Initial dose 1-2 mcg daily or 2-4 mcg three times weekly, adjusted to target iPTH (150-300 pg/mL).
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment beyond standard titration based on iPTH, calcium, and phosphorus levels.
Moderate:
No specific adjustment beyond standard titration based on iPTH, calcium, and phosphorus levels.
Severe:
No specific adjustment beyond standard titration based on iPTH, calcium, and phosphorus levels.
Dialysis:
Used in patients on dialysis; dosing is specific to CKD Stage 5 as described in adult dosing.
Hepatic Impairment:
Mild:
No specific adjustment recommended, but monitor calcium and phosphorus closely.
Moderate:
No specific adjustment recommended, but monitor calcium and phosphorus closely.
Severe:
No specific adjustment recommended, but monitor calcium and phosphorus closely.
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 the parathyroid glands, leading to a reduction in parathyroid hormone (PTH) synthesis and secretion. It also has effects on intestinal calcium absorption, bone remodeling, and renal calcium and phosphorus handling, but with less calcemic and phosphatemic activity compared to calcitriol at therapeutic doses.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 72% (capsules)
Tmax:
2-4 hours
FoodEffect:
No significant effect of food on absorption.
Distribution:
Vd:
Approximately 1.5 L/kg
ProteinBinding:
>99%
CnssPenetration:
Limited
Elimination:
HalfLife:
Approximately 15-30 hours (terminal half-life)
Clearance:
Not available
ExcretionRoute:
Primarily biliary/fecal (approximately 70%), with some renal excretion (approximately 30%).
Unchanged:
Less than 2% of the dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Reduction in PTH levels typically observed within days to weeks of initiating therapy.
PeakEffect:
Peak PTH reduction usually seen within 2-4 weeks of dose stabilization.
DurationOfAction:
Effects on PTH persist as long as therapy is continued; half-life suggests effects last for several days after a single dose.
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 medical attention immediately:
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
+ Feeling tired
+ Headache
+ Upset stomach and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Abnormal heartbeat
Seizures
Frequent urination
Weight loss
Decreased appetite
Unusual 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. Although 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 unusual symptoms that bother you or persist, contact your doctor for guidance:
Diarrhea
Upset stomach or vomiting
Dizziness or headache
Nose or throat irritation
Trouble sleeping
Joint pain
Eye redness
Reporting Side Effects
This list is not exhaustive, and you may experience other 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 medical attention immediately:
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
+ Feeling tired
+ Headache
+ Upset stomach and vomiting
+ Constipation
+ Bone pain
Signs of high or low blood pressure, such as:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Abnormal heartbeat
Seizures
Frequent urination
Weight loss
Decreased appetite
Unusual 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. Although 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 unusual symptoms that bother you or persist, contact your doctor for guidance:
Diarrhea
Upset stomach or vomiting
Dizziness or headache
Nose or throat irritation
Trouble sleeping
Joint pain
Eye redness
Reporting Side Effects
This list is not exhaustive, and you may experience other 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:
- Early signs of hypercalcemia (too much calcium): Weakness, headache, nausea, vomiting, constipation, dry mouth, metallic taste, muscle pain, bone pain.
- Later signs of hypercalcemia: Confusion, drowsiness, loss of appetite, increased thirst, increased urination, weight loss, irregular heartbeat.
- Contact your doctor immediately if you experience any of these symptoms.
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 safely take this medication.
If you are breastfeeding, as you should not breastfeed while taking this medication.
This medication may interact with other medications or health conditions. Therefore, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
Your complete medical history, including any health problems you have
Before starting, stopping, or changing the dose of any medication, including this one, you must consult with your doctor to ensure your safety. It is your responsibility to verify that it is safe to take this medication with all your other medications and health conditions.
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 safely take this medication.
If you are breastfeeding, as you should not breastfeed while taking this medication.
This medication may interact with other medications or health conditions. Therefore, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
Your complete medical history, including any health problems you have
Before starting, stopping, or changing the dose of any medication, including this one, you must consult with your doctor to ensure your safety. It is your responsibility to verify that it is safe to take this medication with all your other medications and health conditions.
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 to minimize potential interactions.
Consuming grapefruit juice or eating grapefruit regularly may interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of this drug, adhere to the 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 drug at least 1 hour before or 4 to 6 hours after taking cholestyramine or mineral oil to ensure optimal absorption.
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 to minimize potential interactions.
Consuming grapefruit juice or eating grapefruit regularly may interact with this medication, so it is crucial to discuss this with your doctor. To maximize the effectiveness of this drug, adhere to the 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 drug at least 1 hour before or 4 to 6 hours after taking cholestyramine or mineral oil to ensure optimal absorption.
Overdose Information
Overdose Symptoms:
- Acute overdose: Hypercalcemia (nausea, vomiting, anorexia, constipation, weakness, fatigue, confusion, polyuria, polydipsia, headache), hyperphosphatemia.
- Chronic overdose: Generalized vascular calcification, nephrocalcinosis, and other soft tissue calcification.
What to Do:
Discontinue paricalcitol immediately. Institute a low-calcium diet. Hydrate the patient. If severe, consider loop diuretics, corticosteroids, calcitonin, or bisphosphonates. Dialysis may be considered in severe cases. Call 1-800-222-1222 (Poison Control) for further guidance.
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 monitored closely.
- Digitalis (Digoxin): Hypercalcemia, a potential side effect of paricalcitol, can potentiate the cardiotoxic effects of digitalis.
Moderate Interactions
- Calcium-containing phosphate binders: Increased risk of hypercalcemia.
- Thiazide diuretics: Increased risk of hypercalcemia.
- Other vitamin D analogs: Additive effects and increased risk of hypercalcemia and hyperphosphatemia.
Monitoring
Baseline Monitoring
Serum Calcium
Rationale: To establish baseline and identify pre-existing hypercalcemia.
Timing: Prior to initiation of therapy.
Serum Phosphorus
Rationale: To establish baseline and identify pre-existing 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.
Calcium x Phosphorus Product
Rationale: To assess risk of ectopic calcification.
Timing: Prior to initiation of therapy.
Routine Monitoring
Serum Calcium
Frequency: At least weekly during dose titration, then monthly once stable.
Target: 8.4-10.2 mg/dL (normal range), avoid hypercalcemia (>10.5 mg/dL)
Action Threshold: If >10.5 mg/dL or persistently elevated, reduce or interrupt paricalcitol dose.
Serum Phosphorus
Frequency: At least weekly during dose titration, then monthly once stable.
Target: 2.5-4.5 mg/dL (normal range), avoid hyperphosphatemia (>5.5 mg/dL)
Action Threshold: If >5.5 mg/dL or persistently elevated, reduce or interrupt paricalcitol dose and/or adjust phosphate binder regimen.
Intact Parathyroid Hormone (iPTH)
Frequency: Every 2-4 weeks during dose titration, then every 1-3 months once stable.
Target: CKD Stage 5: 150-300 pg/mL (KDOQI guidelines)
Action Threshold: Adjust dose to maintain target range; if iPTH falls below target or rises above, adjust dose accordingly.
Calcium x Phosphorus Product
Frequency: At least weekly during dose titration, then monthly once stable.
Target: <55 mg²/dL²
Action Threshold: If >55 mg²/dL², reduce or interrupt paricalcitol dose and/or adjust calcium/phosphate intake/binders.
Symptom Monitoring
- Symptoms of hypercalcemia: Nausea, vomiting, constipation, anorexia, weakness, fatigue, headache, confusion, muscle pain, bone pain, polyuria, polydipsia.
- Symptoms of hyperphosphatemia: Pruritus, bone pain, soft tissue calcification (late sign).
Special Patient Groups
Pregnancy
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.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm based on animal studies (skeletal abnormalities, reduced fetal weight at high doses).
Second Trimester:
Potential for fetal harm based on animal studies.
Third Trimester:
Potential for fetal harm based on animal studies.
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:
Risk unknown. Potential for hypercalcemia in the infant if excreted in milk.
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 potential for age-related decreases in renal function, monitor calcium and phosphorus levels closely.
Clinical Information
Clinical Pearls
- Paricalcitol is a selective VDR activator, meaning it has a more favorable profile regarding hypercalcemia and hyperphosphatemia compared to non-selective vitamin D analogs like calcitriol, especially at therapeutic doses.
- Close and frequent monitoring of serum calcium, phosphorus, and iPTH is critical, especially during dose titration, to prevent hypercalcemia and hyperphosphatemia and to ensure optimal PTH control.
- The calcium x phosphorus product should be maintained below 55 mg²/dL² to minimize the risk of ectopic calcification.
- Patients should be educated on the symptoms of hypercalcemia and instructed to report them immediately.
- Ensure patients are not taking other vitamin D supplements or calcium supplements unless specifically prescribed and monitored by their physician.
Alternative Therapies
- Calcitriol (Rocaltrol, Calcijex): Non-selective vitamin D analog.
- Doxercalciferol (Hectorol): Prodrug of 1α,25-dihydroxyvitamin D2.
- Cinacalcet (Sensipar): Calcimimetic, directly lowers PTH by increasing sensitivity of calcium-sensing receptor on parathyroid gland.
- Etelcalcetide (Parsabiv): Intravenous calcimimetic.
Cost & Coverage
Average Cost:
Varies widely, typically $300-$1000+ per 30 capsules (4mcg)
Generic Available:
Yes
Insurance Coverage:
Tier 2 or 3 (Brand), Tier 1 (Generic) - Varies by plan
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea 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 emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.