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L-Tryptophan

L-Tryptophan, an essential amino acid, is being studied in clinical trials for its potential therapeutic effects on various medical conditions. This article explores the use of L-Tryptophan in clinical trials, focusing on its applications in post-operative delirium, celiac disease, and cancer imaging. These studies aim to evaluate the efficacy and safety of L-Tryptophan supplementation and its potential as a diagnostic tool in different medical contexts.

Table of Contents

What is L-Tryptophan?

L-Tryptophan is an essential amino acid, which means our bodies cannot produce it, and we must obtain it from our diet or supplements. It plays a crucial role in various bodily functions and is being studied for its potential therapeutic benefits in several medical conditions.[1]

Medical Uses of L-Tryptophan

Research is ongoing to explore the potential benefits of L-Tryptophan in various medical conditions. Some of the areas being investigated include:

  • Post-operative delirium in elderly patients
  • Celiac disease symptoms
  • Cancer imaging

L-Tryptophan and Post-Operative Delirium

Post-operative delirium is a common and serious complication in elderly patients after surgery. It can lead to confusion, disorientation, and other cognitive disturbances. Researchers are investigating whether L-Tryptophan supplementation can help reduce the duration and incidence of this condition.[1]

A study is being conducted to compare the effects of L-Tryptophan supplementation versus a placebo in elderly patients (60 years and older) who undergo surgery requiring ICU admission. The key points of this research include:

  • Patients receive either 1 gram of L-Tryptophan or a placebo three times a day.
  • The supplementation starts after surgery and continues for up to 9 doses or until discharge from the ICU.
  • Researchers are measuring the duration and incidence of post-operative delirium using specialized assessment tools.
  • They are also looking at levels of tryptophan and melatonin in the blood, as well as the length of ICU and hospital stays.

This research aims to determine if L-Tryptophan supplementation can help reduce the negative impacts of post-operative delirium in elderly patients.[1]

L-Tryptophan in Celiac Disease

Celiac disease is an autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. Some patients continue to experience symptoms even after following a strict gluten-free diet. Researchers are exploring whether L-Tryptophan supplementation could help alleviate these persistent symptoms.[2]

A study is being conducted to investigate the effects of L-Tryptophan in celiac disease patients who have ongoing symptoms despite following a gluten-free diet for over a year. Here are the key aspects of this research:

  • Participants receive either L-Tryptophan supplements or a placebo for 3 weeks.
  • The dosage is 1000 mg taken three times a day (total daily dose: 3000 mg).
  • Researchers are measuring changes in celiac-related symptoms using various questionnaires and scales.
  • They are also examining changes in the intestinal lining and certain biological markers related to celiac disease activity.

This study aims to determine if L-Tryptophan supplementation can help improve symptoms and quality of life for celiac disease patients who don’t fully respond to a gluten-free diet alone.[2]

L-Tryptophan in Cancer Imaging

Researchers are exploring the use of a modified form of L-Tryptophan in cancer imaging. This technique, called F-Tryptophan PET/CT, may help doctors better distinguish between tumor and non-tumor tissues in various types of cancer.[3]

A study is being conducted to evaluate this imaging technique in patients with different types of cancer, including:

  • Brain tumors (gliomas and metastatic brain tumors)
  • Breast cancer
  • Neuroendocrine tumors
  • Rectal cancer

The key points of this research include:

  • Patients receive a small amount of a radioactive form of L-Tryptophan before undergoing a PET/CT scan.
  • Researchers are measuring how the modified L-Tryptophan is taken up by tumor tissues compared to normal tissues.
  • They are also evaluating the safety of this imaging technique by measuring radiation doses to various organs.

This research aims to determine if F-Tryptophan PET/CT can provide more accurate imaging of tumors, which could potentially help in treatment planning and assessing response to therapy.[3]

Dosage and Administration

The dosage of L-Tryptophan varies depending on the condition being studied:

  • For post-operative delirium: 1 gram three times a day for up to 9 doses.[1]
  • For celiac disease: 1000 mg three times a day (total daily dose: 3000 mg) for 3 weeks.[2]
  • For cancer imaging: A single dose of a radioactive form of L-Tryptophan is given before the imaging procedure.[3]

It’s important to note that these dosages are being used in research studies and may not be appropriate for general use. Always consult with a healthcare provider before starting any new supplement regimen.

Potential Side Effects

As with any medication or supplement, L-Tryptophan may cause side effects. The ongoing studies are monitoring participants for any adverse reactions. If you’re considering L-Tryptophan supplementation, it’s crucial to discuss potential risks and benefits with your healthcare provider.

Aspect Post-operative Delirium Study Celiac Disease Study Cancer Imaging Study
Study Type Double-blinded, placebo-controlled trial Randomized, double-blind, placebo-controlled trial Pilot study
Participant Age 60 years and older 18 to 75 years Not specified
L-Tryptophan Dosage 1 gram enterally three times per day 1000 mg every 8 hours (3000 mg daily) 0.14mCi/kg/5MBq/kg injection (one-time)
Duration Maximum of 9 doses or until ICU discharge 3 weeks Single imaging session
Primary Outcome Duration of post-operative delirium Change in Celiac Symptom Index (CSI) score Difference in tracer uptake between tumor and non-tumor tissue
Key Secondary Outcomes Incidence of delirium, serum tryptophan levels, melatonin levels Quality of life, anxiety and depression, gastrointestinal symptoms Radiation doses to organs, overall radiation dose

FAQ

  • What is L-Tryptophan and why is it being studied in clinical trials? L-Tryptophan is an essential amino acid that plays a role in various bodily functions. It is being studied in clinical trials for its potential benefits in treating post-operative delirium, improving symptoms in celiac disease, and as a diagnostic tool in cancer imaging.
  • How is L-Tryptophan being used in post-operative delirium studies? In post-operative delirium studies, L-Tryptophan is being administered as a supplement to elderly patients (60 years and older) after surgery. The goal is to determine if L-Tryptophan supplementation can reduce the duration and incidence of post-operative delirium compared to a placebo.
  • What is the potential benefit of L-Tryptophan for celiac disease patients? L-Tryptophan is being studied in celiac disease patients who have persistent symptoms despite following a gluten-free diet. The research aims to evaluate if L-Tryptophan supplementation can improve celiac-related symptoms by activating the aryl hydrocarbon receptor (AhR) pathway, which is involved in maintaining gut integrity.
  • How is L-Tryptophan being used in cancer imaging? A modified form of L-Tryptophan, called 1-(2-[18F]FLUOROETHYL)-L-Tryptophan, is being used as a radioactive tracer in PET/CT imaging for various cancers. The goal is to improve the differentiation between tumor and non-tumor tissues, potentially helping in cancer diagnosis and treatment planning.
  • What are some of the outcome measures used in these L-Tryptophan clinical trials? The clinical trials use various outcome measures, including the duration and incidence of post-operative delirium, changes in celiac symptom scores, quality of life assessments, anxiety and depression scales, and measurements of tracer uptake in tumor tissues. Additionally, some studies evaluate changes in blood markers, intestinal health, and radiation dosimetry.

Ongoing Clinical Trials on L-Tryptophan

  • Study on Ketoanalogue Supplementation for Muscle Protection in Patients with Stage 4 and 5 Chronic Kidney Disease on a Low Protein Diet

    Recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    France

  • Study on the Effectiveness of Ketoanalogues in Preventing Muscle Loss in Patients with Nephrotic Syndrome

    Recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Poland

  • Ketosteril Added to Usual Nutrition for Patients Starting Incremental Haemodialysis with Incremental Haemodialysis

    Not yet recruiting

    1 1 1
    Investigated diseases:
    Investigated drugs:
    France

  • Study on the Impact of Acetylcysteine and Drug Combination on Kidney Function in Living Donor Kidney Transplant Patients

    Not yet recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Spain

Glossary

  • L-Tryptophan: An essential amino acid that the body cannot produce on its own and must be obtained through diet or supplements. It plays a role in various bodily functions and is being studied for its potential therapeutic effects.
  • Post-operative Delirium: A common complication in elderly patients after surgery, characterized by confusion, disorientation, and changes in behavior or mental state.
  • Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, causing various digestive symptoms and other health issues.
  • Gluten-Free Diet (GFD): A diet that excludes gluten, a protein found in wheat, barley, and rye, typically followed by people with celiac disease or gluten sensitivity.
  • Aryl Hydrocarbon Receptor (AhR): A nuclear transcription factor involved in activating genes responsible for maintaining gut integrity, which can be influenced by tryptophan metabolites.
  • PET/CT: Positron Emission Tomography/Computed Tomography, an imaging technique that combines PET and CT scans to provide detailed information about the body's structure and function.
  • Radiotracer: A substance containing a radioactive atom that can be detected by imaging equipment, used to track biological processes or highlight specific tissues in the body.
  • Biodistribution: The distribution of a substance, such as a drug or radiotracer, throughout the body's tissues and organs.
  • Radiation Dosimetry: The measurement and calculation of radiation doses absorbed by tissues and organs in the body.
  • Standardized Uptake Value (SUV): A measure used in PET imaging to quantify the concentration of a radiotracer in a specific tissue or organ.

References

  1. https://clinicaltrials.gov/study/NCT00865202
  2. https://clinicaltrials.gov/study/NCT05576038
  3. https://clinicaltrials.gov/study/NCT05556473