Usage
Dibasic calcium phosphate is prescribed to prevent or treat hypocalcemia in individuals with insufficient dietary calcium intake. It’s used to manage conditions arising from low calcium levels, such as osteoporosis, osteomalacia/rickets, hypoparathyroidism, and latent tetany. It’s also prescribed for individuals with increased calcium needs like pregnant or breastfeeding women, postmenopausal women, and patients on medications like phenytoin, phenobarbital, or prednisone. It is classified as a mineral supplement, specifically a calcium supplement. It provides a source of calcium and phosphate, which are essential for bone health and various physiological processes. Its mechanism of action involves providing a readily available source of calcium to increase serum calcium levels, thus supporting normal nerve, muscle, and cellular function, as well as bone mineralization.
Alternate Names
- Dicalcium phosphate
- Calcium monohydrogen phosphate
- Calcium hydrogen phosphate
- Dicalcium orthophosphate, dihydrate
- Calcium phosphate dibasic dihydrate
- Calcium phosphate, dibasic
Brand names vary depending on the manufacturer and formulation. Examples include those combined with Vitamin D and/or Magnesium.
How It Works
Pharmacodynamics: Dibasic calcium phosphate elevates serum calcium levels, restoring normal neuromuscular function and bone mineralization. Calcium is crucial for nerve impulse transmission, muscle contraction, blood clotting, and enzyme activity. Phosphate, a component of ATP, plays a vital role in energy storage and transfer.
Pharmacokinetics:
- Absorption: Calcium absorption occurs primarily in the duodenum and jejunum and is enhanced by acidic environments and vitamin D. Absorption can be hindered by factors like high-fiber diets, phytic acid, oxalic acid, and certain medications.
- Distribution: Absorbed calcium is distributed throughout the body, primarily to bones and teeth (99%). The remaining calcium resides in extracellular fluid, intracellular compartments, and blood.
- Metabolism: Calcium itself is not metabolized. However, its homeostasis is regulated by vitamin D, parathyroid hormone, and calcitonin.
- Elimination: Primarily excreted through the kidneys and to a lesser extent through feces.
Mode of Action: Dibasic calcium phosphate directly provides calcium ions that participate in various biological processes, including bone mineralization, neuromuscular function, and enzymatic reactions. It does not have specific receptor binding, enzyme inhibition, or neurotransmitter modulation properties.
Dosage
Standard Dosage
Adults:
The typical adult dose ranges from 1-2 grams of elemental calcium per day, divided into multiple doses for optimal absorption. The exact dosage and formulation will depend on the specific calcium supplement used and the individual’s needs.
Children:
Pediatric dosing varies according to age and health status. Recommended dietary allowances should be followed, with supplementation only under the guidance of a healthcare professional.
Special Cases:
- Elderly Patients: May require dose adjustments based on renal function and potential drug interactions.
- Patients with Renal Impairment: Close monitoring of calcium and phosphate levels is essential due to impaired excretion. Dosage adjustments may be necessary.
- Patients with Hepatic Dysfunction: No specific dosage adjustments are typically required.
- Patients with Comorbid Conditions: Considerations include underlying metabolic or endocrine disorders that may affect calcium metabolism.
Clinical Use Cases
Dibasic calcium phosphate is not typically used for specific clinical procedures like intubation, surgical procedures, mechanical ventilation, or ICU use. It’s primarily used for long-term management of hypocalcemia and related conditions.
Dosage Adjustments
Dosage adjustments are based on serum calcium and phosphate levels, renal function, and potential drug interactions.
Side Effects
Common Side Effects:
- Constipation
- Bloating
- Gas
- Upset stomach
Rare but Serious Side Effects:
- Hypercalcemia (high blood calcium levels)
- Kidney stones
Long-Term Effects:
- Milk-alkali syndrome (rare, but possible with chronic high doses)
Adverse Drug Reactions (ADR):
- Allergic reactions (rare)
Contraindications
- Hypercalcemia
- Severe renal impairment
- Kidney stones
- Hypoparathyroidism (certain types)
Drug Interactions
- Bisphosphonates: Reduced absorption of bisphosphonates
- Tetracycline antibiotics: Reduced absorption of tetracyclines
- Quinolone antibiotics: Reduced absorption of quinolones
- Levothyroxine: Reduced absorption of levothyroxine
- Thiazide diuretics: May increase risk of hypercalcemia
- Digoxin: May enhance digoxin toxicity in the presence of hypercalcemia
Pregnancy and Breastfeeding
Dibasic calcium phosphate is generally considered safe during pregnancy and breastfeeding when taken within the recommended dietary allowances. Higher doses should be used only if clearly needed and under medical supervision.
Drug Profile Summary
- Mechanism of Action: Provides calcium to increase serum calcium levels, supporting normal physiological functions.
- Side Effects: Constipation, bloating, gas, upset stomach; rarely hypercalcemia and kidney stones.
- Contraindications: Hypercalcemia, severe renal impairment, kidney stones.
- Drug Interactions: Bisphosphonates, tetracyclines, quinolones, levothyroxine, thiazide diuretics, digoxin.
- Pregnancy & Breastfeeding: Generally safe within recommended dietary allowances.
- Dosage: Varies based on age and indication; typically 1-2 grams elemental calcium daily in divided doses.
- Monitoring Parameters: Serum calcium and phosphate levels, renal function.
Popular Combinations
- Vitamin D: Enhances calcium absorption.
- Magnesium: Supports bone health and may improve calcium absorption.
Precautions
- Monitor serum calcium and phosphate levels, especially in patients with renal impairment.
- Ensure adequate hydration.
- Assess dietary calcium intake to adjust supplementation accordingly.
- Caution in patients with history of kidney stones.
- Monitor for signs of hypercalcemia.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dibasic Calcium Phosphate?
A: The standard adult dosage is 1-2 grams of elemental calcium per day, divided into multiple doses. Pediatric and special population dosing should be determined based on individual needs and under medical supervision.
Q2: What are the primary uses of Dibasic Calcium Phosphate?
A: It’s primarily used to treat and prevent hypocalcemia and related conditions like osteoporosis, rickets/osteomalacia, and hypoparathyroidism.
Q3: What are the common side effects of Dibasic Calcium Phosphate?
A: Common side effects are gastrointestinal and include constipation, gas, bloating, and upset stomach.
Q4: What are the serious side effects of Dibasic Calcium Phosphate?
A: Though rare, serious side effects include hypercalcemia and kidney stones.
Q5: Are there any contraindications to using Dibasic Calcium Phosphate?
A: Yes, contraindications include hypercalcemia, severe renal impairment, and kidney stones.
Q6: Does Dibasic Calcium Phosphate interact with other medications?
A: Yes, it can interact with medications such as bisphosphonates, tetracyclines, quinolones, levothyroxine, thiazide diuretics, and digoxin.
Q7: Can Dibasic Calcium Phosphate be taken during pregnancy and breastfeeding?
A: Generally safe within recommended dietary allowances. Consult a physician for appropriate dosing.
Q8: What are the long-term effects of taking Dibasic Calcium Phosphate?
A: Long-term high doses might lead to milk-alkali syndrome, although it is rare.
Q9: How should Dibasic Calcium Phosphate be taken?
A: Take with food for better absorption. Divide the daily dose into multiple administrations for doses greater than 600 mg elemental calcium.
Q10: Should any lab values be monitored during treatment?
A: Serum calcium and phosphate levels should be monitored, especially in patients with renal impairment.
This information is current as of February 16, 2025. Medical knowledge is constantly evolving, so it is essential to consult up-to-date resources and guidelines for the most current information.
