AMINOSYN 3.5% M
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMINOSYN 3.5% M (AMINOSYN 3.5% M).
Aminosyn 3.5% M is a crystalline amino acid solution providing essential and nonessential amino acids for protein synthesis, tissue repair, and maintenance of nitrogen balance. It acts as a substrate for anabolic processes and helps correct negative nitrogen balance.
| Metabolism | Amino acids are primarily metabolized in the liver via transamination, deamination, and urea cycle; some amino acids are also metabolized in other tissues. No specific CYP450 metabolism. |
| Excretion | Amino acids in Aminosyn 3.5% M are primarily eliminated via metabolism (utilization for protein synthesis, energy, and other metabolic pathways). Minimal amounts are excreted unchanged in urine (less than 5% of infused amino acids) via glomerular filtration. There is no significant biliary or fecal elimination. |
| Half-life | The terminal elimination half-life of infused amino acids is typically 0.5-2 hours in patients with normal renal and metabolic function, reflecting rapid uptake and metabolism by tissues. In hepatic or renal impairment, half-life may be prolonged due to decreased clearance. |
| Protein binding | Amino acids are not significantly bound to plasma proteins (< 5% bound). |
| Volume of Distribution | The volume of distribution for individual amino acids ranges from 0.2 to 0.4 L/kg, approximating extracellular fluid volume. This reflects distribution into total body water, with most amino acids rapidly taken up by cells. |
| Bioavailability | Intravenous: 100% (complete bioavailability). Not available for oral or other routes as it is an IV solution. |
| Onset of Action | Intravenous infusion: Onset of action is immediate upon infusion, as amino acids become available for metabolic processes within minutes. Clinical effects on nitrogen balance and protein synthesis require hours to days of continuous infusion. |
| Duration of Action | Intravenous infusion: Duration of action is dependent on infusion rate and metabolic demand. Amino acids are cleared rapidly from plasma (half-life ~30-60 minutes), so effects on plasma concentrations subside within 2-4 hours after infusion stops. Sustained improvement in nitrogen balance requires continuous or intermittent administration. |
Intravenous infusion; typical adult dose: 1 to 1.5 g amino acids/kg/day (equivalent to 28.6 to 42.9 mL/kg/day of 3.5% solution). Administer via central or peripheral line at a rate not exceeding 0.5 g amino acids/kg/hour.
| Dosage form | INJECTABLE |
| Renal impairment | GFR < 30 mL/min: reduce dose to 0.5-0.8 g amino acids/kg/day; monitor BUN and serum electrolytes. GFR 30-60 mL/min: use 0.8-1.0 g/kg/day. Not recommended in patients requiring dialysis without specific adjustment. |
| Liver impairment | Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50% and monitor ammonia. Child-Pugh Class C: contraindicated due to risk of hepatic encephalopathy; use alternative branched-chain amino acid formulations. |
| Pediatric use | Weight-based dosing: 1-2 g amino acids/kg/day (28.6-57.1 mL/kg/day of 3.5% solution). For infants, consider 2-3 g/kg/day; titrate based on nitrogen balance and growth parameters. Administer via central line with gradual rate escalation. |
| Geriatric use | Initiate at 0.8 g amino acids/kg/day (22.9 mL/kg/day) and titrate slowly; monitor for fluid overload and renal function. Use with caution due to age-related decline in GFR; maximum dose 1.2 g/kg/day. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMINOSYN 3.5% M (AMINOSYN 3.5% M).
| Breastfeeding | Amino acids are normal components of breast milk. No M/P ratio available. Excretion into milk is not expected to be clinically significant. Use with caution in nursing mothers. |
| Teratogenic Risk | Aminosyn 3.5% M (amino acids) is used as a component of parenteral nutrition. No teratogenic effects are expected at standard doses. There are no adequate studies in pregnant women; use only if clearly needed. Fetal risk cannot be ruled out but likely low due to endogenous amino acids. |
| Fetal Monitoring |
■ FDA Black Box Warning
Not available.
| Serious Effects |
["Patients with inborn errors of amino acid metabolism (e.g., maple syrup urine disease, phenylketonuria).","Severe electrolyte or acid-base imbalance.","Uncorrected metabolic instability (e.g., severe uremia, anuria).","Hypersensitivity to any component."]
| Precautions | ["Must be used under close medical supervision.","Monitor for signs of fluid overload, electrolyte imbalances, and metabolic complications (e.g., hyperglycemia, hyperammonemia).","Risk of infection (catheter-related sepsis) from IV administration.","Use with caution in patients with renal insufficiency, hepatic impairment, or metabolic disorders (e.g., phenylketonuria)."] |
| Food/Dietary | No oral food intake is required; amino acid infusion may affect protein metabolism. Avoid concurrent use of nephrotoxic drugs. |
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| Monitor electrolytes, acid-base balance, blood glucose, liver and renal function, serum ammonia, and nutritional status. Fetal monitoring as per routine prenatal care. |
| Fertility Effects | No known adverse effects on fertility. Essential for normal reproductive function. |
| Clinical Pearls | Aminosyn 3.5% M is a peripheral parenteral nutrition (PPN) solution; monitor for signs of phlebitis due to hypertonicity. Use within 24 hours of opening; discard any unused portion. Do not add medications without checking compatibility. Assess renal function prior to use; adjust in renal impairment. |
| Patient Advice | This solution is given through a vein to provide nutrition when you cannot eat. · Report any pain, redness, or swelling at the IV site immediately. · You may experience low blood sugar if infusion stops suddenly; nausea or vomiting may occur. · Adhere to scheduled blood tests to monitor electrolytes and kidney function. |