AMINOSYN II 3.5% IN PLASTIC CONTAINER
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMINOSYN II 3.5% IN PLASTIC CONTAINER (AMINOSYN II 3.5% IN PLASTIC CONTAINER).
Aminosyn II 3.5% is a crystalline amino acid solution that provides essential and nonessential amino acids for protein synthesis and maintenance of nitrogen balance. The amino acids serve as substrates for protein synthesis, and their metabolism yields nitrogen for ureagenesis and carbon skeletons for gluconeogenesis or oxidation.
| Metabolism | Amino acids are metabolized primarily in the liver via deamination, transamination, and decarboxylation. Nitrogen is converted to urea via the urea cycle. Carbon skeletons are utilized in gluconeogenesis, the Krebs cycle, or fatty acid synthesis. |
| Excretion | Aminosyn II 3.5% is a crystalline amino acid solution. The amino acids are metabolized and utilized for protein synthesis. Excess nitrogen is converted to urea in the liver and excreted renally as urea. Approximately 80-90% of infused amino acids are incorporated into proteins or metabolized; the remainder is excreted in urine as urea and other nitrogenous wastes. Fecal excretion is negligible (less than 2%) as amino acids are not significantly eliminated in bile. In patients with renal impairment, urea excretion is decreased, leading to azotemia. |
| Half-life | The terminal elimination half-life of infused amino acids is not typically defined as a single value because they are rapidly cleared from plasma for protein synthesis and metabolic processes. For labeled amino acids, the plasma clearance half-life ranges from 10-30 minutes. Clinically, the half-life is short; continuous infusion is required to maintain plasma amino acid levels. In patients with hepatic or renal dysfunction, half-life may be prolonged. |
| Protein binding | Amino acids are not significantly bound to plasma proteins (less than 5% binding). They exist free in plasma and are transported into cells via specific transporters. |
| Volume of Distribution | Aminosyn II 3.5% is a mixture of amino acids with varying distribution volumes. Collectively, the apparent volume of distribution (Vd) for total amino acids is approximately 0.2-0.4 L/kg, reflecting distribution into extracellular fluid and rapid cellular uptake. Individual amino acids may have different Vd values. |
| Bioavailability | Intravenous: 100% bioavailability as it is administered directly into the bloodstream. No oral or other routes are applicable for this formulation. |
| Onset of Action | Intravenous infusion: Onset of protein-sparing effect and positive nitrogen balance occurs within 24-48 hours of continuous infusion, based on reduced urinary nitrogen excretion and improved nitrogen balance. |
| Duration of Action | Intravenous infusion: The effects on nitrogen balance and protein synthesis persist as long as the infusion continues. After discontinuation, the metabolic effects wane over 24-48 hours. Plasma amino acid levels return to baseline within hours after stopping infusion. |
Intravenous infusion of 3.5% amino acid solution at a rate of 1-2 mL/kg/hour (equivalent to 0.035-0.07 g amino acids/kg/hour) for protein supplementation, not to exceed 0.2 g nitrogen/kg/day. Dosage individualized based on metabolic needs and clinical response.
| Dosage form | INJECTABLE |
| Renal impairment | For GFR 30-50 mL/min: reduce dose by 25%; GFR 15-29 mL/min: reduce dose by 50%; GFR <15 mL/min or dialysis: avoid use due to risk of azotemia and accumulation of amino acids. |
| Liver impairment | Child-Pugh class A: no adjustment; Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: contraindicated due to risk of hepatic encephalopathy and ammonia accumulation. |
| Pediatric use | Neonates and infants: 0.5-1 g amino acids/kg/day initially, titrate upward to 2-3 g/kg/day as tolerated; children: 1-2 g/kg/day. Administer as continuous IV infusion at a rate not exceeding 0.1 g amino acids/kg/hour. |
| Geriatric use | Initiate at lower end of adult dosing (1 mL/kg/hour) and titrate slowly due to decreased renal function and higher risk of fluid overload; monitor nitrogen balance and renal function closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMINOSYN II 3.5% IN PLASTIC CONTAINER (AMINOSYN II 3.5% IN PLASTIC CONTAINER).
| Breastfeeding | Excretion into breast milk unknown. Considered compatible with breastfeeding due to endogenous nature of amino acids. M/P ratio not determined. |
| Teratogenic Risk | No teratogenic risk identified for standard amino acid solution. Pregnancy category C: use only if clearly needed. No fetal risks reported in first, second, or third trimester. |
| Fetal Monitoring |
■ FDA Black Box Warning
Not for use in patients with hepatic coma or metabolic disorders involving impaired nitrogen utilization. Risk of hyperammonemia, especially in patients with hepatic insufficiency or inborn errors of amino acid metabolism.
| Serious Effects |
["Hepatic coma or severe hepatic insufficiency","Inborn errors of amino acid metabolism","Severe renal failure without dialysis","Hypersensitivity to any component"]
| Precautions | Administer only to patients with normal renal function and adequate urine output. Monitor serum electrolytes, blood urea nitrogen, ammonia, and acid-base balance. Use with caution in patients with heart failure, renal impairment, or on diuretics due to risk of fluid overload. Risk of hyperglycemia or hypoglycemia; adjust insulin accordingly. Do not administer simultaneously with blood through the same infusion set due to risk of agglutination. |
| Food/Dietary | No dietary restrictions when administered parenterally; however, oral nutrition may be contraindicated in patients requiring parenteral nutrition. Monitor serum glucose if patient is also receiving enteral nutrition. |
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| Monitor maternal fluid and electrolyte balance, renal function, and signs of volume overload. No specific fetal monitoring required. |
| Fertility Effects | No known adverse effects on fertility or reproductive function. |
| Clinical Pearls | Aminosyn II 3.5% is a crystalline amino acid solution used for parenteral nutrition; monitor serum electrolytes, BUN, and ammonia levels; avoid rapid infusion to prevent hyperammonemia; contraindicated in patients with hepatic coma or metabolic acidosis; use with caution in renal insufficiency; do not administer simultaneously with blood through same infusion set due to risk of pseudoagglutination. |
| Patient Advice | This medication is a protein supplement given intravenously to provide essential amino acids when you cannot eat or absorb nutrients normally. · Report any signs of allergic reaction such as rash, itching, or difficulty breathing immediately. · Inform your healthcare provider if you experience headaches, confusion, nausea, or vomiting, as these may indicate high ammonia levels. · The solution should appear clear; do not use if discolored or containing particles. · Regular blood tests will be needed to monitor your kidney and liver function, as well as electrolyte levels. |