A Placebo Controlled Trial Of L-Tryptophan In Post-Operative Delirium
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ClinicalTrials.gov Identifier: NCT00865202 |
Recruitment Status :
Completed
First Posted : March 19, 2009
Results First Posted : June 1, 2017
Last Update Posted : June 1, 2017
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Condition or disease | Intervention/treatment | Phase |
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Post-operative Delirium | Drug: L-tryptophan supplementation Drug: placebo | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 301 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | A Placebo Controlled Trial Of L-Tryptophan In Post-Operative Delirium |
Study Start Date : | December 2008 |
Actual Primary Completion Date : | December 2012 |
Actual Study Completion Date : | December 2012 |

Arm | Intervention/treatment |
---|---|
Experimental: L-Tryptophan
L-tryptophan supplementation (1 gram enterally three times per day) starting post-operatively and continuing for a maximum of 9 doses or the time of discharge from ICU (whichever occurs first)
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Drug: L-tryptophan supplementation
L-tryptophan 1 gram enterally TID for a maximum of nine doses or to be discontinued at the time of discharge from the ICU (whichever occurs first)
Other Name: L-tryptophan 1 gm PO TID starting the evening of surgery |
Placebo Comparator: Placebo
Similar appearing placebo administered post-operatively (1 enterally three times per day) for a total of nine doses or discharge from ICU (whichever occurs first)
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Drug: L-tryptophan supplementation
L-tryptophan 1 gram enterally TID for a maximum of nine doses or to be discontinued at the time of discharge from the ICU (whichever occurs first)
Other Name: L-tryptophan 1 gm PO TID starting the evening of surgery Drug: placebo Similar appearing placebo administered post-operatively (1 enterally TID) for a total of nine doses or discharge from ICU (whichever occurs first)
Other Name: Similar appearing placebo |
- Duration of Post-operative Delirium [ Time Frame: post-operatively daily in ICU until discharged from ICU ]
- Incidence of Post-operative Delirium [ Time Frame: post-operatively daily in ICU until discharged from ICU ]
The incidence and/or duration of excitatory (hyperactive and mixed) post-operative delirium, diagnosed by the Confusion Assessment Method-ICU (CAM-ICU) with the Richmond Agitation Sedation Score (RASS), will be reduced with enteral L-tryptophan supplementation (1 gm TID for the first 3 post-op days), compared to placebo, in older patients (≥ 60 years) undergoing operations requiring ICU admission.
The incidence and/or duration of all types of post-operative delirium, diagnosed by the CAM-ICU with the RASS, will be reduced with enteral L-tryptophan supplementation (1 gm TID for the first 3 post-op days), compared to placebo, in older patients (≥ 60 years) undergoing operations requiring ICU admission.
- Level of Post-operative Serum Tryptophan [ Time Frame: post-operative day number two blood draw ]
- Level of Post-operative Melatonin [ Time Frame: Blood draw on post-operative day number two ]
- Length of Post-operative ICU and Hospital Stay [ Time Frame: length of post-op hospital stay ]

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Ages Eligible for Study: | 60 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Included subjects will be 60 years and older undergoing an operation with a planned ICU admission post-operatively.
Exclusion Criteria:
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Medications that, when combined with tryptophan, increase the risk of serotonin syndrome. The classes of medications include:
- monoamine oxidase inhibitors
- selective serotonin reuptake inhibitors
- serotonin-norepinephrine reuptake inhibitors
- triptans
- opioids
- central nervous system stimulants
- bupropion
- St. John's Wort
- Patients who undergo an operation on their brain.
- Factors which prevent delirium assessment with the CAM-ICU: vision impairment or non-fluent English speakers.
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A lowered seizure threshold including:
- history of seizure disorder
- alcohol abuse defined by a high AUDIT score (>8 females and >13 males)
- benzodiazepine or barbiturate abuse within three months of the study
- OR a positive urine toxicology screen for alcohol, benzodiazepines or barbiturates.
- Significant liver disease (Child's class B or greater) or significant renal disease (Creatinine ≥2.0).
- History of Huntington's or Addison's disease. (As requested by the FDA)
- History of bipolar disorder or a psychotic disorder (such as a psychotic major depression, schizophrenia, schizoaffective disorder, or psychosis in Alzheimer's disease or other dementia). (As requested by the FDA)
- Women who are not post-menopausal. (As requested by the FDA)

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00865202
United States, Colorado | |
Denver Veterans Affairs Medical Center | |
Denver, Colorado, United States, 80220 |
Principal Investigator: | Thomas Robinson, MD | University of Colorado, Denver |
Responsible Party: | University of Colorado, Denver |
ClinicalTrials.gov Identifier: | NCT00865202 |
Other Study ID Numbers: |
08-0543 |
First Posted: | March 19, 2009 Key Record Dates |
Results First Posted: | June 1, 2017 |
Last Update Posted: | June 1, 2017 |
Last Verified: | May 2017 |
delirium surgery operation geriatric complication |
Delirium Confusion Neurobehavioral Manifestations Neurologic Manifestations Nervous System Diseases Neurocognitive Disorders |
Mental Disorders Tryptophan Antidepressive Agents, Second-Generation Antidepressive Agents Psychotropic Drugs |