Amino Acid + Calcium

Approved (Labeled Uses):

• Total parenteral nutrition (TPN): providing both protein (amino acids) and calcium supplementation when enteral feeding is contraindicated.
• Correction or prevention of hypocalcemia in patients receiving prolonged parenteral nutrition, especially neonates and infants.

Clinically Accepted Off‑Label Uses:

• Critically ill adults or children in catabolic states (trauma, burns, sepsis, major surgery) who require both protein and calcium support.
• Malabsorption syndromes with high risk of calcium depletion + negative nitrogen balance.
• Premature or very low birth weight neonates requiring combined intravenous protein and calcium as part of early nutrition.
• Patients with renal impairment on dialysis who need adjusted amino acid plus calcium dosing under monitoring.

Amino Acid Component (by weight):

• Adults: typical protein dosing: 0.8–2.0 g/kg/day, structured by stress level (see previous amino acid-only profile).

Calcium Component:

• Adults: 10–15 mEq (200–300 mg elemental calcium) per liter of TPN; typical daily total ~10–20 mEq/day depending on plasma and bone status.
• Pediatric/Neonatal:
• Extremely low birth weight infants: up to 2–3 mEq/kg/day (40–60 mg Ca/kg/day).
• Term infants: ~1.5–2 mEq/kg/day.
• Older infants/children: adjusted to body weight and age-specific calcium requirements (~1000 mg/day older children).

Special Populations:

• Renal impairment: lower calcium dosing (e.g. 5–10 mEq/day) if risk of hypercalcemia or vascular calcification; monitor serum calcium and phosphate.
• Hepatic impairment: standard amino acid dosing with calcium phased per liver function; calcium metabolism less altered but monitor albumin and ionized Ca.

Administration & Rate:

• Infused intravenously as part of a combined TPN admixture (dextrose, amino acids, lipids, electrolytes).
• Calcium salts typically added as calcium gluconate (less irritant than chloride).
• Infuse gradually; avoid rapid infusion of calcium to minimize risk of arrhythmia or precipitation (mixed only with appropriate phosphorus and bicarbonate levels).

Dose Adjustments:

• Adjust according to serum electrolytes, renal clearance, acid-base balance, and urine output.
• Adequate vitamin D, phosphate, and magnesium levels are required for calcium utilization and to prevent precipitation.

The amino acid component supplies essential substrates for protein synthesis, reducing catabolism and promoting tissue repair and nitrogen balance. The calcium component supports vital physiological functions by maintaining extracellular calcium concentrations, enabling neuromuscular transmission, enzymatic activity (cofactor role), and skeletal mineralization. Together in one infusion, they address both protein malnutrition and calcium deficiency especially during prolonged parenteral nutrition where oral intake is insufficient.

• Absorption: Both amino acids and calcium are delivered directly into the bloodstream.
• Distribution: Amino acids rapidly distribute into intracellular and extracellular water compartments; calcium distributes in plasma (ionized and protein-bound) and extracellular fluid, with tight homeostatic regulation.
• Metabolism: Amino acids are used for protein synthesis or catabolized via transamination/deamination; calcium is not metabolized but plays roles in signaling pathways and bone matrix deposition.
• Excretion: Free nitrogen excreted as urea via kidneys; excess amino acids may appear in urine. Calcium is excreted predominantly by kidneys; serum excretion adjusts according to parathyroid and vitamin D regulation.
• Onset & Half-Life: Amino acid effects align with infusion rate; individual amino acid half-lives vary. Ionized calcium half-life is minutes (regulatory balance), but total body calcium turn-over is slower over days to weeks.

Pregnancy:

• No formal pregnancy category; considered nutritional support and electrolyte replacement when needed. Calcium needs increase in the second and third trimesters, especially if maternal intake is inadequate. Benefits outweigh theoretical risk when properly monitored.

Lactation:

• Amino acids and calcium are normal constituents of breast milk. Parenteral provision of these nutrients is not expected to cause harm to breastfed infants when used appropriately. Monitor maternal serum calcium and ensure electrolytes are balanced. If mother has metabolic or renal dysfunction, caution is advised.

• Primary Class: Nutritional support electrolyte mixture.
• Subclass: Parenteral amino acid solution combined with calcium salt, component of total parenteral nutrition electrolyte strategy.

• Hypersensitivity to any component—amino acids or calcium salts (e.g., calcium gluconate).
• Hypercalcemia or known high serum calcium levels.
• Conditions with risk of calcium-phosphate precipitation (high phosphate without adequate balance).
• Inborn errors of amino acid metabolism (e.g. MSUD), unless specialized formulation available.
• Severe renal failure without capability to monitor and adjust for calcium excretion.

• High-Risk Groups: Premature neonates, renal or hepatic disease, elderly, cardiac compromised, those at risk for calcium overload.
• Major Risks: Hypercalcemia (leading to arrhythmias, soft tissue calcification), electrolyte precipitation, line complications, infection risk.
• Monitoring: Frequent checks of ionized calcium, serum phosphorus, magnesium, renal function, fluid balance, electrolytes, and acid-base status.
• Warning Signs: Arrhythmias (bradycardia, tachycardia), muscle weakness or cramps, nausea/vomiting, altered mental status, infusion site pain or precipitates in the bag.

Common:

• Local phlebitis or irritation at infusion site.
• Mild nausea or flushing (especially if infused too rapidly).
• Electrolyte shifts: hyper- or hypocalcemia if adjustments are delayed.

Serious / Rare:

• Hypercalcemia, potentially causing cardiac arrhythmias, calcific vascular or soft tissue deposition.
• Calcium-phosphate precipitation in the infusion line or TPN bag (riskful if mismatched additives).
• Catheter-related infection or thrombosis.
• Hypersensitivity to calcium salts (rare)—e.g., rash, bronchospasm.

Onset usually during or shortly after infusion; severity depends on rate and dosage; careful rate control minimizes risk.

• Drug–drug: Vitamin D analogs increase calcium absorption and may contribute to hypercalcemia if co-administered without adjustment.
• Electrolyte interactions: High phosphate doses risk precipitation with calcium; simultaneous magnesium depletion impairs calcium utilization.
• Drug–food: Not applicable (intravenous route).
• Alcohol: Not relevant to IV combination.
• Enzyme systems: No classic CYP450 interactions; metabolism and electrolyte handling are hormonal and renal pathways.

• No regulatory changes in approved labeling.
• Nutritional guidelines increasingly recommend early combined amino acid and calcium administration in ICU, neonatal, and surgical settings to prevent both protein and mineral deficiencies.
• Clinical protocols stress strict calcium-phosphate ratio control to avoid precipitation and ensure bioavailability.
• In neonatal care, earlier provision of calcium (alongside amino acids) within the first hours of life is now standard to support bone mineralization and nitrogen balance.

• Store unopened solutions at 20 °C to 25 °C, away from excessive heat or direct sunlight.
• Do not freeze; discard if cloudy, crystallized, or precipitates visible.
• Prepared TPN mixtures containing amino acids and calcium should be refrigerated at 2 °C–8 °C and used within 24 hours; discard if past that time.
• Before infusion, warm to room temperature gradually; gently mix to avoid precipitation (do not shake vigorously).
• Prepare mixtures using aseptic technique; inspect lines and bags for clarity and absence of particulate matter.