1. Clinical Overview
Amino Acids (10% w/v) is a sterile, hypertonic, intravenous solution containing a balanced mixture of essential and non-essential L-amino acids, providing 10 grams of amino acids per 100 mL. It is a fundamental component of parenteral nutrition (PN) therapy, designed to provide the nitrogen source required for protein synthesis, tissue repair, and maintenance of positive nitrogen balance in patients unable to meet their nutritional needs via the enteral route. It serves as the building blocks for proteins, enzymes, hormones, and other vital biomolecules.
| Onset | Duration | Bioavailability |
|---|---|---|
| Immediate upon intravenous infusion; amino acids enter the systemic circulation and become available for cellular uptake and utilization. | Metabolic effects persist for several hours post-infusion, depending on the patient's metabolic rate, nutritional status, and concurrent energy supply (dextrose/lipids). | 100% (Intravenous administration). |
2. Mechanism of Action
Provides exogenous L-amino acids, which are the essential substrates for the synthesis of body proteins (structural, enzymatic, hormonal). By supplying nitrogen and carbon skeletons, it reverses catabolism, promotes anabolism, supports wound healing, and maintains immune function. It helps achieve positive nitrogen balance when combined with adequate energy.
3. Indications & Uses
- As a nitrogen source in Parenteral Nutrition for patients with non-functioning gastrointestinal tract (e.g., intestinal obstruction, ileus)
- Severe short bowel syndrome
- Major abdominal surgeries requiring prolonged bowel rest
- Severe acute pancreatitis (nil per os phase)
- High-output enterocutaneous fistulas
4. Dosage & Administration
Adult Dosage: Individualized based on nutritional assessment. Typical range: 0.8 to 1.5 grams of amino acids per kg of body weight per day. For a 70 kg patient: 56 to 105 g/day. The 10% solution provides 10 g/100 mL, so daily volume ranges from ~560 mL to 1050 mL, infused over 12-24 hours as part of a total parenteral nutrition (TPN) admixture.
Administration: FOR CENTRAL VENOUS ADMINISTRATION ONLY (standard 10% solution). Must be mixed with dextrose, lipids, electrolytes, vitamins, and trace elements in a TPN bag under aseptic conditions (preferably by pharmacy). Administer via an infusion pump at a constant rate over the prescribed period (usually 12-24 hours). Do not infuse rapidly. Use a dedicated line or a Y-site connection with proper filtration (1.2 micron filter recommended). Never administer directly; always as part of TPN.
5. Side Effects
Common side effects may include:
- Venous irritation or thrombophlebitis (if infused peripherally)
- Nausea
- Vomiting
- Fever (pyrogenic reaction)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Tetracyclines | May complex with calcium in TPN, leading to precipitation. Add separately. | Major |
| Warfarin | Vitamin K in TPN multivitamins can antagonize warfarin effect. Monitor INR closely. | Major |
| Insulin | Required to manage hyperglycemia from TPN dextrose. Dose must be adjusted based on TPN infusion rate. | Major |
| Phenytoin | TPN may decrease phenytoin serum levels. Administer phenytoin separately and monitor levels. | Moderate |
7. Patient Counselling
- Do report any pain, redness, or swelling at the IV site immediately.
- Do inform all healthcare providers that you are on TPN.
- Do maintain strict hygiene around the catheter site as taught.
- Don't tamper with the infusion pump or tubing.
- Don't skip scheduled blood tests.
8. Toxicology & Storage
Overdose: Symptoms of overdose are manifestations of metabolic complications: Severe metabolic acidosis, hyperammonemia (vomiting, lethargy, seizures), azotemia, hyperglycemia, hyperosmolar state, fluid overload leading to pulmonary edema, and electrolyte imbalances.
Storage: Store below 25°C. Do not freeze. Protect from light. The prepared TPN admixture is chemically stable for a limited time (usually 24-48 hours under refrigeration). Always check the pharmacy-prepared label for exact expiry. Use immediately after removal from refrigeration. Single-use only. Discard any unused portion.