Amino Acid Formulations for Renal Failure

Pronunciation: a-MEE-noe AS-id
Class: Amino acid combinations

Trade Names

Aminosyn-RF 5.2%
- Injection, solution 5.2%

NephrAmine 5.4%
- Injection, solution 5.4%

Pharmacology

Administration of essential amino acids to uremic patients results in the utilization of retained urea in protein synthesis. As a result, BUN levels may decrease and many symptoms of azotemia may resolve.

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Indications and Usage

IV nutritional support for patients with uremia or those with potentially reversible acute renal failure.

Contraindications

Severe, uncorrected electrolyte and acid-base imbalance; hyperammonemia; decreased circulating blood volume; inborn errors of amino acid metabolism ( NephrAmine only); hypersensitivity to 1 or more amino acids in the solution ( NephrAmine only).

Dosage and Administration

IV 300 to 600 mL/day. Higher dosages may be administered cautiously if more nitrogen and calories are required in severely stressed patients in acute renal failure who cannot eat.

IV 250 to 500 mL/day.

IV 0.5 to 1 g of essential amino acids/kg per day will meet the requirements of the majority of children. Initial daily dosage should be low and increased slowly. Frequent laboratory and clinical monitoring is strongly recommended, especially in very young patients, to avoid clinically significant elevations of serum ammonia and plasma amino acid levels. Max dosage is 1 g/kg/day.

May include dextrose/insulin, fat emulsion, electrolyte supplementation, and vitamins.

General Advice

• Guide dosage by fluid, glucose, and nitrogen tolerances, as well as the patient's metabolic and clinical response.
• Hypertonic admixtures may be administered by continuous infusion through a central venous catheter with the tip located in the superior vena cava. Solutions administrated by peripheral vein should not exceed twice normal serum osmolarity (718 mOsmol/L).
• Administration time for a single bottle and set should never exceed 24 h.
• Incompatibilities: Potentially incompatible ions (calcium, phosphate) may be added to alternative infusion bottles to avoid precipitation.
• Initial infusion rates for central venous administration should be slow, generally 20 to 30 mL/h for the first 6 to 8 h. Increments of 10 mL/h for each hour are suggested to a max rate of 60 to 100 mL/h.

Storage/Stability

Store between 68° and 77°F. Avoid excessive heat. Protect from freezing. Protect from light until use.

Drug Interactions

None well documented.

Adverse Reactions

Cardiovascular

Venous thrombosis.

Local

Infection at the injection site.

Metabolic-Nutritional

Hyperammonemia; hypermethionemia; hypervolemia; metabolic, fluid, electrolyte, and acid-base imbalances; phosphorous deficiency.

Miscellaneous

Febrile response.

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Use with caution, especially in low-birth-weight infants. Frequently monitor glucose because of the risk of hyperglycemia. Elevated plasma amino acid levels (eg, hypermethionemia) and hyperammonemia may occur; consider amino acid formulations developed specifically for infants and children.

Elderly

Use with caution; more prone to fluid overload and electrolyte imbalance.

Renal Function

Amino acid injection does not replace dialysis and conventional supportive therapy in patients with renal failure. Monitor fluid balance to avoid circulatory overload, particularly in association with cardiac insufficiency.

Hepatic Function

May result in plasma amino acid imbalances, hyperammonemia, or CNS deterioration. Use with caution.

Special Risk Patients

Use solutions containing acetate ion with great care in patients with metabolic or respiratory alkalosis.

Sulfite Sensitivity

NephrAmine contains a sulfite that may cause allergic-type reactions, including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people.

Administration

Administer strongly hypertonic nutrient solutions through an indwelling IV catheter with the tip located in the superior vena cava. Abrupt cessation of hypertonic dextrose infusion may result in rebound hypoglycemia.

Aluminum toxicity

Parenteral products may contain aluminum that may be toxic. Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired. Premature neonates are particularly at risk.

BUN changes

BUN may increase, especially in patients with renal or hepatic impairment. Monitor levels and discontinue infusion or reduce nitrogen content if BUN levels continue to rise inappropriately.

Diabetes

Use special care when giving hypertonic glucose to diabetic or prediabetic and uremic patients. Insulin may be required to prevent severe hyperglycemia.

Electrolyte changes

Hypokalemia, hypophosphatemia, or hypomagnesemia may occur. Electrolyte replacement therapy may be necessary.

Essential fatty acid deficiency

Essential fatty acid deficiency (EFAD) may occur in patients on long-term TPN. The use of fat emulsion to provide 4% to 10% of total caloric intake as linoleic acid may prevent EFAD.

Exogenous calories

Provide exogenous calories concurrently with amino acids in patients receiving long-term total nutrition or if the patient has inadequate fat stores. Administration of amino acids without carbohydrates may result in the accumulation of ketone bodies in the blood.

Fluid/Solute overload

May occur and result in dilution of serum electrolyte concentrations, overhydration, congested states, or pulmonary edema.

Hyperammonemia

May be associated with mental retardation in infants. Monitor blood ammonia levels frequently.

Metabolic complications

These have included metabolic acidosis, hypophosphatemia, alkalosis, hyperglycemia and glycosuria, osmotic diuresis and dehydration, rebound hypoglycemia, elevated liver enzymes, hypo- and hypervitaminosis, electrolyte imbalances, and elevated plasma amino acid levels and hyperammonemia in infants and children. Monitor frequently, especially the first few days of therapy. Administration of glucose at a rate exceeding the patient's utilization may lead to hyperglycemia, coma, and death.

Myocardial infarction

In patients with MI, accompany amino acid infusion with dextrose.

Sepsis

The constant risk of sepsis is present during central venous nutrition.

Overdosage

Symptoms

None reported.

Patient Information

• Advise patient that medication will be prepared and administered by a health care provider in a hospital setting.

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