AMINOSYN 8.5%
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMINOSYN 8.5% (AMINOSYN 8.5%).
Aminosyn 8.5% is a crystalline amino acid solution that provides a source of nitrogen and essential/non-essential amino acids for protein synthesis, tissue repair, and maintenance of nitrogen balance. It serves as a substrate for metabolic pathways, including gluconeogenesis and ketogenesis, and supports immune function and enzyme production.
| Metabolism | Amino acids are metabolized primarily in the liver via transamination, deamination, and oxidation. The carbon skeletons enter the Krebs cycle or are converted to glucose or ketone bodies. Nitrogen is incorporated into urea via the urea cycle and excreted renally. |
| Excretion | Renal elimination of infused amino acids as urea, ammonia, and other nitrogenous waste products; minimal biliary/fecal excretion (<2%) |
| Half-life | Variable; amino acids have rapid distribution and metabolic half-lives of minutes to hours; terminal half-life of infused amino acid mixtures is approximately 1–2 hours for most components in patients with normal hepatic function |
| Protein binding | Minimal to none (<5%) for free amino acids; no significant binding to plasma proteins |
| Volume of Distribution | 0.2–0.4 L/kg, approximating extracellular fluid volume; distributes primarily into lean body mass and total body water |
| Bioavailability | Intravenous: 100% (only route of administration); not available orally or via other routes |
| Onset of Action | Intravenous: immediate onset of metabolic utilization upon infusion; nitrogen balance improvement observed within 24–48 hours of continuous infusion |
| Duration of Action | Duration of metabolic effects persists for 4–6 hours post-infusion; continuous infusion is typically required to maintain positive nitrogen balance in catabolic patients |
Intravenous infusion: 1.0-1.5 g amino acids/kg/day (11.8-17.6 mL/kg/day of 8.5% solution) via central line; rate not to exceed 0.1 g amino acids/kg/hour.
| Dosage form | INJECTABLE |
| Renal impairment | GFR <50 mL/min: restrict to 0.5-0.8 g/kg/day; monitor BUN. GFR <25 mL/min: consider essential amino acid formulations only (not standard Aminosyn). |
| Liver impairment | Child-Pugh B or C: reduce dose by 50% or use branched-chain amino acid enriched formula; avoid in decompensated cirrhosis with encephalopathy. |
| Pediatric use | Neonates: 2-3 g/kg/day IV; infants/children: 1-2.5 g/kg/day IV. Use 8.5% solution; adjust for fluid restriction. Rate typically 0.1-0.15 g amino acids/kg/hour. |
| Geriatric use | Start at lower end of adult range (0.8-1.0 g/kg/day); monitor renal function; limit infusion rate to ≤0.08 g/kg/hour to avoid fluid overload. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMINOSYN 8.5% (AMINOSYN 8.5%).
| Breastfeeding | There is no information on the excretion of Aminosyn 8.5% into human milk. The M/P ratio is unknown. After intravenous administration, amino acids are normally present in breast milk; supplemental amino acids are unlikely to pose a risk to the infant. Caution is recommended, but it is generally considered compatible with breastfeeding when clinically indicated. |
| Teratogenic Risk | Aminosyn 8.5% (crystalline amino acid solution) is not known to be teratogenic in humans. There are no adequate and well-controlled studies in pregnant women. In general, intravenous amino acid solutions are considered low risk for teratogenicity when used appropriately for maternal nutritional support. However, risks may be associated with the underlying maternal condition requiring parenteral nutrition. |
■ FDA Black Box Warning
None
| Serious Effects |
["Severe hepatic failure with hyperammonemia","Inborn errors of amino acid metabolism (e.g., phenylketonuria, maple syrup urine disease)","Severe azotemia with oliguria or anuria not responsive to dialysis","Hypersensitivity to any component of the solution"]
| Precautions | ["Risk of hyperammonemia, especially in patients with hepatic insufficiency or urea cycle disorders","Electrolyte imbalances (e.g., hyperkalemia, hypophosphatemia) requiring monitoring","Fluid overload in patients with renal or cardiac impairment","Metabolic acidosis, particularly with excessive chloride content","Vein irritation, phlebitis, or thrombosis at infusion site","Aluminum toxicity with prolonged use, especially in renal impairment"] |
| Food/Dietary | No direct food interactions as Aminosyn is administered intravenously. However, enteral intake should be coordinated with parenteral nutrition to avoid overfeeding. In patients transitioning to oral intake, monitor for signs of refeeding syndrome, especially if malnourished. |
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| Fetal Monitoring | Monitor maternal electrolytes, serum amino acids, blood glucose, renal function, liver function, fluid balance, and acid-base status. In pregnancy, fetal monitoring may include ultrasound for growth and amniotic fluid assessment, and fetal heart rate monitoring if maternal complications arise. Monitor for signs of hyperammonemia, metabolic acidosis, or volume overload. |
| Fertility Effects | No specific studies on fertility effects with Aminosyn 8.5%. In general, adequate nutrition may improve fertility in malnourished women. There is no evidence of adverse effects on fertility at therapeutic doses. |
| Clinical Pearls | Aminosyn 8.5% is a crystalline amino acid solution used for parenteral nutrition. It must be administered via central venous access due to high osmolarity (approximately 850 mOsm/L). Monitor serum electrolytes, renal function, and acid-base balance regularly. Avoid rapid infusion to prevent hyperosmolar syndrome. Check for incompatibility with lipid emulsions and other additives; use a dedicated line or y-site with caution. In patients with hepatic or renal impairment, adjust dosage to avoid nitrogenous waste accumulation. |
| Patient Advice | This medication is given through a central vein to provide nutrition when you cannot eat. · Report any signs of infection at the infusion site, such as redness, swelling, or pain. · Tell your healthcare provider if you experience nausea, vomiting, headache, or difficulty breathing. · Do not stop or adjust the infusion rate without consulting your doctor. · Regular blood tests are needed to monitor your kidney function and electrolyte levels. |