What are the clinical uses and dosages of L-alanyl L-glutamine (L-alanyl L-glutamine)?

Clinical Uses and Dosages of L-alanyl L-glutamine

Parenteral L-alanyl L-glutamine supplementation may be considered in patients who cannot be fed adequately enterally and therefore require exclusive parenteral nutrition, with a standard dosage of 0.5 g/kg/day. 1

Indications for L-alanyl L-glutamine

Parenteral Administration

• Parenteral L-alanyl L-glutamine is primarily indicated for patients who cannot be adequately fed enterally and require exclusive parenteral nutrition 1
• Particularly beneficial in critically ill ICU patients requiring parenteral nutrition, with doses ranging from 0.2 to 0.57 g/kg/day 1
• May improve outcomes in surgical patients, especially those undergoing gastrointestinal surgery, though evidence is mixed 1

Oral Administration

• Oral L-glutamine (not specifically the dipeptide form) is FDA-approved to reduce acute complications of sickle cell disease in adults and pediatric patients 5 years and older 2
• Currently, no clear recommendation can be given regarding oral glutamine supplementation in surgical patients 1

Dosage Guidelines

Parenteral Dosage

• Standard dosage: 0.5 g/kg/day of L-alanyl L-glutamine dipeptide 1
• For critically ill patients: 0.2-0.4 g/kg/day of L-glutamine (equivalent to 0.3-0.6 g/kg/day of alanyl-glutamine dipeptide) 1
• Typical range in clinical studies: 10-30 g glutamine/24 hours 1

Oral Dosage (for sickle cell disease)

• Weight-based dosing:
  • <30 kg: 5 g twice daily (10 g/day)
  • 30-65 kg: 10 g twice daily (20 g/day)

  • 65 kg: 15 g twice daily (30 g/day) 2

• Should be mixed with 8 oz (240 mL) of beverage or 4-6 oz of food before ingestion 2

Clinical Benefits and Evidence

Critical Care Benefits

• Reduced mortality risk in critically ill patients requiring parenteral nutrition (RR 0.67, CI 0.48-0.92) 1
• May improve 6-month survival in ICU patients treated for ≥9 days (66.7% with glutamine vs. 40% control) 3
• Helps maintain plasma glutamine levels, which are often depleted in critical illness 1

Surgical Patient Benefits

• May improve nitrogen balance and maintain intestinal permeability in postoperative patients 4
• Some studies show reduced hospital length of stay in surgical patients 4
• Potentially beneficial for intra- and postoperative glucose-insulin homeostasis and recovery of bowel function after colonic resection 1

Other Potential Benefits

• Functions as a nitrogen shuttle and contributes to production of other amino acids, glucose, nucleotides, protein, and glutathione 5
• Primary metabolic fuel for small intestine enterocytes, lymphocytes, macrophages, and fibroblasts 5
• May help maintain immune function in septic patients 6

Cautions and Contraindications

• High-dose parenteral glutamine is contraindicated in critically ill patients with acute kidney injury or chronic kidney disease 7
• A multicentre RCT showed high-dose glutamine administration in critically ill patients with organ dysfunction was associated with increased mortality 1
• No clear contraindications for oral L-glutamine are listed in FDA labeling 2
• Common adverse reactions (>10%) with oral L-glutamine include constipation, nausea, headache, abdominal pain, cough, pain in extremity, back pain, and chest pain 2

Clinical Decision Algorithm

1. Assess patient's ability to tolerate enteral nutrition

   • If enteral nutrition is adequate → glutamine supplementation generally not indicated 1
   • If enteral nutrition is inadequate or contraindicated → consider parenteral nutrition with glutamine

2. Evaluate patient for contraindications

   • Check for renal failure, hepatic failure, or shock → avoid high-dose glutamine if present 7
   • Assess for multi-organ dysfunction → use caution with glutamine supplementation 1

3. Determine appropriate route and dosage

   • For parenteral use: 0.5 g/kg/day in patients requiring exclusive PN 1
   • For oral use in sickle cell disease: weight-based dosing as per FDA guidelines 2

4. Monitor for efficacy and safety

   • Track clinical outcomes, nitrogen balance, and intestinal function 4
   • Monitor for adverse reactions, particularly in critically ill patients 2