Usage
Calcium gluconate is prescribed for the treatment and prevention of hypocalcemia (low blood calcium levels). It is also used to treat conditions arising from calcium deficiency such as hypocalcemic tetany and hypoparathyroidism. Additionally, it is used in the management of hypermagnesemia (high blood magnesium levels) and hyperkalemia (high blood potassium levels), specifically for antagonizing cardiac toxicity in hyperkalemia. It can also be used in cardiac arrest due to hypermagnesemia, hyperkalemia or calcium channel blocker overdose and for hydrofluoric acid burns. Its pharmacological classification is as an electrolyte supplement and a mineral supplement. It works by directly providing a source of calcium to replenish depleted stores and restore normal physiological functions dependent on calcium.
Alternate Names
There are no widely used alternate names for calcium gluconate. Brand names vary depending on the manufacturer and region but commonly include names like Kalcium Glukonat and Calcium Sandoz.
How It Works
Pharmacodynamics: Calcium plays a vital role in numerous physiological processes including nerve impulse transmission, muscle contraction, blood coagulation, and bone formation. Calcium gluconate elevates serum calcium levels, correcting the deficit and alleviating symptoms of hypocalcemia like muscle spasms, tetany, and cardiac arrhythmias. In hyperkalemia, calcium stabilizes the cardiac cell membrane, protecting against the adverse effects of elevated potassium.
Pharmacokinetics:
- Absorption: Oral absorption is incomplete and variable, influenced by factors like vitamin D, pH, and dietary components. Intravenous administration delivers calcium directly into the bloodstream resulting in rapid action.
- Metabolism: Calcium is not metabolized in the conventional sense.
- Elimination: Primarily excreted by the kidneys. Some calcium is eliminated in feces and through sweat.
Mode of Action: Calcium exerts its effects by binding to various proteins, including calcium-binding proteins like calmodulin, which regulate numerous enzymes and cellular processes. It also acts on cell membrane ion channels, influencing membrane excitability and neurotransmitter release.
Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: No specific receptor binding, enzyme inhibition, or neurotransmitter modulation has been attributed to calcium gluconate as its action involves replenishing calcium, a ubiquitous ion crucial for numerous physiological functions.
Dosage
Standard Dosage
Adults:
- Hypocalcemia: IV bolus: 1-2 g (10-20 mL of a 10% solution) over 10-20 minutes. This may be repeated every 10-60 minutes until symptoms resolve. Continuous IV infusion: Initiate at 5.4 to 21.5 mg/kg/hour.
- Hyperkalemia with ECG changes: 1-3g IV over 2-5 minutes. Repeat dose every 5-10 minutes if ECG changes persist.
- Hypermagnesemia: 1-2g IV over 5-10 minutes.
Children:
- Hypocalcemia: IV bolus: 50-200 mg/kg/dose (0.5 to 2 mL/kg/dose of a 10% solution), diluted to 50 mg/mL, administered over 30-60 minutes. Maintenance: 0.5-1.5 mmol/kg/day of elemental calcium.
- Hyperkalemia: 20-50 mg/kg/dose over 5-10 minutes.
- Cardiac arrest: 60-100 mg/kg/dose every 10 minutes (max 3000mg/dose)
Special Cases:
- Elderly Patients: Similar to adult dosing, but monitor closely due to potential for age-related decline in renal function.
- Patients with Renal Impairment: Dose reduction may be necessary; monitor calcium levels closely.
- Patients with Hepatic Dysfunction: Dose adjustments are generally not needed.
- Patients with Comorbid Conditions: Consider underlying conditions and potential drug interactions when adjusting dosage.
Clinical Use Cases:
- Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use, Emergency Situations: Dosage adjusted based on the patient’s specific needs and clinical presentation of hypocalcemia. Monitor calcium levels closely and titrate the dose to effect.
Dosage Adjustments:
- Renal/Hepatic Dysfunction, Metabolic Disorders, or Genetic Polymorphisms: Specific guidelines for dose adjustments are based on the severity of dysfunction and clinical response.
Side Effects
Common Side Effects
- Nausea
- Vomiting
- Constipation
- Bradycardia (with rapid administration)
- Local reactions at the injection site
Rare but Serious Side Effects
- Cardiac arrhythmias
- Syncope
- Tissue necrosis (with extravasation)
- Hypercalcemia
Long-Term Effects
Long-term effects are uncommon with appropriate use but can include nephrocalcinosis with excessive oral intake.
Adverse Drug Reactions (ADR)
Severe bradycardia or other cardiac arrhythmias, tissue necrosis with extravasation, and allergic reactions require immediate intervention.
Contraindications
- Hypercalcemia
- Ventricular fibrillation
- Hypersensitivity to calcium gluconate
- Severe renal failure
- Patients receiving cardiac glycosides (digoxin)
- Neonates receiving ceftriaxone
Drug Interactions
- Cardiac Glycosides: Calcium can enhance the effects of digoxin, potentially leading to toxicity.
- Thiazide Diuretics: May increase serum calcium levels.
- Bisphosphonates, Calcium Channel Blockers, Tetracycline Antibiotics: Calcium may decrease absorption of these drugs.
- Ceftriaxone: Co-administration with calcium in neonates can form precipitates.
Pregnancy and Breastfeeding
Calcium gluconate is generally considered safe during pregnancy and breastfeeding. However, large doses should be avoided.
Drug Profile Summary
- Mechanism of Action: Replenishes calcium stores, normalizes physiological processes, stabilizes cardiac membranes.
- Side Effects: Nausea, vomiting, constipation, bradycardia, local reactions. Rarely, arrhythmias and extravasation reactions.
- Contraindications: Hypercalcemia, ventricular fibrillation, digoxin therapy, ceftriaxone in neonates.
- Drug Interactions: Digoxin, thiazide diuretics, bisphosphonates, calcium channel blockers, tetracycline antibiotics, ceftriaxone.
- Pregnancy & Breastfeeding: Generally safe.
- Dosage: Adults: 1-2 g IV bolus. Children: 50-200 mg/kg IV.
- Monitoring Parameters: Serum calcium levels, ECG, heart rate, injection site.
Popular Combinations
Often used alongside other electrolytes based on the clinical context (e.g., potassium chloride, magnesium sulfate).
Precautions
- General Precautions: Evaluate renal function, cardiac function, and electrolyte levels before administering.
- Specific Populations: Monitor elderly patients and those with renal impairment closely.
- Lifestyle Considerations: No specific lifestyle considerations except advising patients about potential side effects.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Calcium Gluconate?
A: Adults: 1-2g IV; Children: 50-200 mg/kg IV. Dosing is adjusted according to the severity of hypocalcemia and specific clinical scenario.
Q2: How should Calcium Gluconate be administered?
A: Intravenously, either as a slow bolus or a continuous infusion. Never administer intramuscularly or subcutaneously.
Q3: What are the common side effects of Calcium Gluconate?
A: Nausea, vomiting, constipation, bradycardia, and local injection site reactions are the common side effects.
Q4: When is Calcium Gluconate contraindicated?
A: Contraindicated in hypercalcemia, ventricular fibrillation, patients on digoxin, and neonates receiving ceftriaxone.
Q5: How does Calcium Gluconate interact with other medications?
A: May interact with digoxin, thiazide diuretics, bisphosphonates, calcium channel blockers, tetracyclines, and ceftriaxone.
Q6: Can Calcium Gluconate be used during pregnancy and breastfeeding?
A: Generally considered safe, but avoid large doses. Consult with an obstetrician if necessary.
Q7: What are the signs of Calcium Gluconate overdose?
A: Symptoms of hypercalcemia, including nausea, vomiting, constipation, confusion, and cardiac arrhythmias.
Q8: What monitoring is necessary during Calcium Gluconate therapy?
A: Monitor serum calcium levels, ECG, heart rate, and the injection site for any adverse reactions.
A: Stop the infusion immediately and aspirate any remaining drug. Hyaluronidase injection and local heat or cold packs may be considered. Consult a plastic surgery specialist if the area of extravasation is large or if necrosis is observed.
Q10: What is the role of Calcium Gluconate in cardiac arrest?
A: Used in specific situations like hyperkalemia, hypermagnesemia, or calcium channel blocker overdose. It helps stabilize the cardiac membrane and potentially restore normal rhythm. It’s not routinely used in all cases of cardiac arrest.
