Calcium Acetate 667mg Tablets
It is used to lower high phosphate levels.
Drug Class
Phosphate binder
Pharmacologic Class
Calcium salt
Pregnancy Category
Category C
FDA Approved
Sep 1991
DEA Schedule
Not Controlled
Overview
What is this medicine?
Calcium acetate is a medication used by people with kidney disease who are on dialysis. It helps to lower high levels of phosphate in your blood. It works by binding to the phosphate in the food you eat, preventing your body from absorbing it. This bound phosphate is then passed out of your body in your stool.
How to Use This Medicine
Taking Your Medication Correctly
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor.
Carefully read all the information provided with your medication and follow the instructions closely.
Take your medication with meals to help your body absorb it properly.
Adhere to the diet plan recommended by your doctor to maximize the effectiveness of your medication.
Do not chew your medication, as this can affect its absorption and efficacy.
Storing and Disposing of Your Medication
To maintain the quality and safety of your medication:
Store it at room temperature in a dry place, away from the bathroom.
Keep all medications in a secure location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your doctor or pharmacist.
If you have questions about disposing of your medication, consult with your pharmacist. You may also want to explore local drug take-back programs for a safe and environmentally friendly way to dispose of your medication.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take it as soon as you remember, unless it is close to the time for your next scheduled dose.
If it is near the time for your next dose, skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses, as this can increase the risk of side effects.
To ensure you get the most benefit from your medication, follow these steps:
Take your medication exactly as directed by your doctor.
Carefully read all the information provided with your medication and follow the instructions closely.
Take your medication with meals to help your body absorb it properly.
Adhere to the diet plan recommended by your doctor to maximize the effectiveness of your medication.
Do not chew your medication, as this can affect its absorption and efficacy.
Storing and Disposing of Your Medication
To maintain the quality and safety of your medication:
Store it at room temperature in a dry place, away from the bathroom.
Keep all medications in a secure location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your doctor or pharmacist.
If you have questions about disposing of your medication, consult with your pharmacist. You may also want to explore local drug take-back programs for a safe and environmentally friendly way to dispose of your medication.
What to Do If You Miss a Dose
If you miss a dose of your medication:
Take it as soon as you remember, unless it is close to the time for your next scheduled dose.
If it is near the time for your next dose, skip the missed dose and resume your regular dosing schedule.
Do not take two doses at the same time or take extra doses, as this can increase the risk of side effects.
Lifestyle & Tips
- Take calcium acetate with each meal and snack that contains phosphate. It must be taken with food to work properly.
- Do not crush or chew the tablets unless specifically instructed by your doctor or pharmacist.
- Do not take calcium acetate at the same time as other medications like certain antibiotics (e.g., ciprofloxacin, doxycycline), thyroid hormones, or iron supplements. Separate doses by at least 1-2 hours, or as advised by your doctor.
- Follow your doctor's recommendations for a low-phosphate diet.
- Avoid taking other calcium-containing products (e.g., antacids, other calcium supplements) unless directed by your doctor, as this can lead to too much calcium in your blood.
Available Forms & Alternatives
Available Strengths:
- Calcium Carb 1250mg/5ml Susp
- Calcium Chloride 10% Inj, 10ml
- Calcium Oyster Shell 500mg Tablets
- Calcium 500mg Tablets
- Calcium Acetate 667mg Capsules
- Calcium 600+d (400u) Tablets
- Calcium 600mg Tablets
- Calcium 600mg + D Tablets
- Calcium 500 W/vit D3 Tablets
- Calcium Citrate 250mg Tablets
- Calcium Antacid 500mg Chw Tablets
- Calcium Carb 500mg Chewtablets
- Calcium Acetate 667mg Tablets
- Calcium Carb 648mg Tablets
- Calcium 500mg W/ Vit D Chw Tablets
- Calcium Citrate W/ Vit D Tablets
- Calcium/d3 600mg-200iu Tablets
- Calcium 500mg Chewable Tablets
- Calcium Gluconate 10% Inj, 50ml
- Calcium Antacid 750mg Chw Tablets
- Calcium Citrate 200mg Tablets
- Calcium Citrate+d3 Tablets
- Calcium Gluconate 10% Inj, 10ml
- Calcium Glu/nacl 1gm/100ml Soln
- Cal Glu/nacl 2000mg/100ml Inj 100ml
- Cal Glu/nacl 1gm/50ml Inj, 50ml
- Calcium Gluc 100mg/ml Inj, 50ml
- Calcium Gluconate 10% Inj, 100ml
- Calcium Gluc 100mg/ml Inj, 100ml
- Calcium Gluc 100mg/ml Inj, 10ml
Dosing & Administration
Adult Dosing
Standard Dose:
Initial dose of 1334 mg (2 tablets) orally with each meal. Titrate dose to control serum phosphate levels.
Dose Range:
667 - 2000 mg
Condition-Specific Dosing:
hyperphosphatemia_ESRD:
Initial 1334 mg (2 tablets) with each meal. Most patients require 3-4 tablets with each meal. Total daily dose typically 4-9 tablets (2668-6003 mg) to achieve target phosphate levels. Maximum daily elemental calcium intake from all sources should not exceed 2000 mg.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established (used off-label, dose individualized based on serum phosphate and calcium levels)
Adolescent:
Not established (used off-label, dose individualized based on serum phosphate and calcium levels)
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment needed, primary use is in ESRD.
Moderate:
No specific adjustment needed, primary use is in ESRD.
Severe:
Primary indication is for hyperphosphatemia in patients with end-stage renal disease (ESRD). Dose titration based on serum phosphate and calcium levels.
Dialysis:
Used in patients on dialysis to control hyperphosphatemia. Monitor serum calcium and phosphate closely to avoid hypercalcemia.
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Pharmacology
Mechanism of Action
Calcium acetate is a phosphate binder. When taken with meals, it combines with dietary phosphate to form insoluble calcium phosphate, which is then excreted in the feces. This reduces the absorption of phosphate from the gastrointestinal tract, thereby lowering serum phosphate concentrations in patients with end-stage renal disease.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 20-30% of ingested calcium is absorbed, depending on dietary factors and vitamin D status. Acetate is absorbed and metabolized to bicarbonate.
Tmax:
Not directly applicable for phosphate binding; calcium absorption peaks within 1-2 hours.
FoodEffect:
Must be taken with meals to bind dietary phosphate effectively.
Distribution:
Vd:
Not specifically defined for calcium acetate as a whole; calcium ions distribute widely throughout the body, primarily in bone.
ProteinBinding:
Approximately 40% of serum calcium is protein-bound (primarily to albumin).
CnssPenetration:
Limited (calcium ions are tightly regulated in CNS, but can cross blood-brain barrier under certain conditions).
Elimination:
HalfLife:
Calcium has complex kinetics; no single half-life. Unabsorbed calcium and calcium phosphate complex are eliminated in feces. Absorbed calcium is primarily excreted renally.
Clearance:
Not directly applicable for calcium acetate; renal clearance of absorbed calcium varies with serum levels and renal function.
ExcretionRoute:
Fecal (unabsorbed calcium phosphate), Renal (absorbed calcium)
Unchanged:
Not applicable (calcium is an ion, acetate is metabolized)
Pharmacodynamics
OnsetOfAction:
Immediate (phosphate binding occurs as soon as it mixes with food in the GI tract)
PeakEffect:
Within hours of ingestion (related to meal digestion and phosphate binding)
DurationOfAction:
Duration of effect is limited to the presence of food in the GI tract; requires dosing with each meal.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Attention Immediately
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
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
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. Contact your doctor or seek medical help if you experience:
Upset stomach
Any other side effects that bother you or do not go away
Note: This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. For medical advice about side effects, contact 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, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
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
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. Contact your doctor or seek medical help if you experience:
Upset stomach
Any other side effects that bother you or do not go away
Note: This is not an exhaustive list of possible side effects. If you have questions or concerns, consult your doctor. For medical advice about side effects, contact 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:
- Symptoms of too much calcium in your blood (hypercalcemia): feeling sick to your stomach (nausea), throwing up (vomiting), constipation, loss of appetite, stomach pain, muscle weakness, feeling tired, confusion, increased thirst, increased urination.
- 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 symptoms you experienced.
If you have elevated calcium levels in your blood.
This medication may interact with other health conditions or medications. To ensure safe use, it is crucial to:
Inform your doctor and pharmacist about all medications you are taking, including prescription and over-the-counter drugs, natural products, and vitamins.
Discuss all your health problems with your doctor and pharmacist.
Verify that 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.
If you have elevated calcium levels in your blood.
This medication may interact with other health conditions or medications. To ensure safe use, it is crucial to:
Inform your doctor and pharmacist about all medications you are taking, including prescription and over-the-counter drugs, natural products, and vitamins.
Discuss all your health problems with your doctor and pharmacist.
Verify that 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.
To avoid interactions, do not take calcium supplements or products containing calcium, such as antacids, while taking this medication. Additionally, this drug may interfere with the absorption of other oral medications. If you are taking other medications by mouth, your doctor may advise you to take them at a different time than this medication to ensure proper absorption.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is crucial to discuss the potential benefits and risks of this medication with your doctor. This will help you make an informed decision about your treatment and the well-being of your baby.
To avoid interactions, do not take calcium supplements or products containing calcium, such as antacids, while taking this medication. Additionally, this drug may interfere with the absorption of other oral medications. If you are taking other medications by mouth, your doctor may advise you to take them at a different time than this medication to ensure proper absorption.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is crucial to discuss the potential benefits and risks of this medication with your doctor. This will help you make an informed decision about your treatment and the well-being of your baby.
Overdose Information
Overdose Symptoms:
- Severe hypercalcemia symptoms: severe constipation, persistent nausea/vomiting, severe abdominal pain, muscle weakness, bone pain, confusion, stupor, coma, kidney stones, cardiac arrhythmias.
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222.
Drug Interactions
Contraindicated Interactions
- Hypercalcemia (pre-existing)
Major Interactions
- Digoxin (increased risk of arrhythmias due to hypercalcemia)
- Tetracyclines (e.g., doxycycline, minocycline) - reduced absorption
- Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) - reduced absorption
- Bisphosphonates (e.g., alendronate, risedronate) - reduced absorption
- Thyroid hormones (e.g., levothyroxine) - reduced absorption
- Iron supplements (reduced absorption)
Moderate Interactions
- Calcium channel blockers (e.g., verapamil, diltiazem) - potential reduction in efficacy
- Thiazide diuretics (increased risk of hypercalcemia)
- Vitamin D analogs (e.g., calcitriol, paricalcitol) - increased risk of hypercalcemia
Minor Interactions
- Other calcium-containing products (e.g., antacids, other calcium supplements) - increased risk of hypercalcemia
Monitoring
Baseline Monitoring
Serum Calcium
Rationale: To establish baseline and guide initial dosing, and to identify pre-existing hypercalcemia.
Timing: Prior to initiation of therapy
Serum Phosphate
Rationale: To establish baseline and guide initial dosing, and to assess the severity of hyperphosphatemia.
Timing: Prior to initiation of therapy
Serum Parathyroid Hormone (PTH)
Rationale: To assess bone mineral disease and guide overall management of mineral and bone disorder in ESRD.
Timing: Prior to initiation of therapy
Serum Albumin
Rationale: To correct serum calcium levels for hypoalbuminemia.
Timing: Prior to initiation of therapy
Routine Monitoring
Serum Calcium
Frequency: Weekly initially, then monthly or as clinically indicated
Target: Typically 8.4-9.5 mg/dL (corrected for albumin)
Action Threshold: If >10.2 mg/dL (corrected), consider dose reduction or discontinuation of calcium acetate and other calcium-containing products. Investigate cause of hypercalcemia.
Serum Phosphate
Frequency: Weekly initially, then monthly or as clinically indicated
Target: Typically 2.5-4.5 mg/dL (KDOQI guidelines)
Action Threshold: If above target, consider dose increase of calcium acetate or addition of other phosphate binders. If below target, consider dose reduction.
Serum Parathyroid Hormone (PTH)
Frequency: Every 3-6 months or as clinically indicated
Target: Typically 2-9 times the upper limit of normal for the assay (KDOQI guidelines)
Action Threshold: If persistently high or low, adjust phosphate binder, vitamin D analog, or calcimimetic therapy as appropriate.
Symptom Monitoring
- Symptoms of hypercalcemia: nausea, vomiting, constipation, anorexia, abdominal pain, muscle weakness, fatigue, confusion, lethargy, polyuria, polydipsia, cardiac arrhythmias.
- Symptoms of hypophosphatemia (rare with appropriate dosing): muscle weakness, bone pain.
Special Patient Groups
Pregnancy
Category C. Calcium acetate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Close monitoring of maternal serum calcium levels is essential to avoid hypercalcemia, which can be harmful to both mother and fetus.
Trimester-Specific Risks:
First Trimester:
Risk of hypercalcemia to mother and potential fetal effects.
Second Trimester:
Risk of hypercalcemia to mother and potential fetal effects.
Third Trimester:
Risk of hypercalcemia to mother and potential fetal effects, including fetal hypercalcemia, which can lead to neonatal hypocalcemia, tetany, and seizures.
Lactation
L3 (Moderately Safe). Calcium is naturally present in breast milk. While calcium acetate is used to manage hyperphosphatemia, excessive maternal calcium intake could theoretically increase calcium levels in breast milk. Use with caution. Monitor the breastfed infant for signs of hypercalcemia (e.g., constipation, poor feeding, lethargy).
Infant Risk:
Low to moderate risk. Monitor for signs of hypercalcemia in the infant.
Pediatric Use
Safety and efficacy have not been established in pediatric patients. However, it is used off-label in children with hyperphosphatemia, with dosing individualized based on serum phosphate and calcium levels. Close monitoring of calcium and phosphate is crucial due to potential for hypercalcemia and impact on bone development.
Geriatric Use
No specific dose adjustments are typically required for elderly patients. However, geriatric patients may be more susceptible to hypercalcemia due to age-related decreases in renal function or concomitant use of other medications (e.g., thiazide diuretics, vitamin D analogs). Monitor serum calcium levels closely.
Clinical Information
Clinical Pearls
- Always instruct patients to take calcium acetate *with* meals and snacks to ensure effective phosphate binding.
- Emphasize the importance of regular blood tests (calcium and phosphate) to ensure the dose is appropriate and to prevent hypercalcemia.
- Advise patients to report any symptoms of hypercalcemia immediately, such as constipation, nausea, or confusion.
- Remind patients about potential drug interactions, especially with antibiotics (fluoroquinolones, tetracyclines), thyroid hormones, and iron supplements, and to separate administration times.
- Calcium acetate can cause constipation; advise patients on dietary fiber and fluid intake, or discuss stool softeners if needed.
Alternative Therapies
- Sevelamer carbonate (Renvela, Renagel)
- Lanthanum carbonate (Fosrenol)
- Sucroferric oxyhydroxide (Velphoro)
- Ferric citrate (Auryxia)
- Aluminum hydroxide (less common due to toxicity concerns)
Cost & Coverage
Average Cost:
Varies widely, typically $30-$150 per 90 tablets (generic)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (generic), Tier 3 or higher (brand)
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 this 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, including the amount taken and the time it happened, to facilitate prompt and effective treatment.