CI

At a glance

ClinicalIndex Comparison Record
Phase 2Completed· 88 enrolled
Drug / intervention
N-acetylcysteine (NAC) +2 moredrug
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT04013555
NCT04013555Phase 2Completed

The Effects of Kynurenine Aminotransferase Inhibition in People With Schizophrenia

University of Maryland, Baltimore·interventional·Posted Jul 9, 2019·Updated Feb 11, 2026

In Brief

A Phase 2 clinical trial evaluating N-acetylcysteine (NAC), Placebo, and 1 other intervention for Schizophrenia and 2 related conditions. Completed, enrolled 88 participants across 1 site.

Detailed Summary

Kynurenic acid (KYNA) is a naturally occurring chemical in the brain. Studies with rodents indicate that levels of KYNA can impact levels of the neurotransmitters glutamate and dopamine. One way to reliably increase KYNA levels is by ingesting the amino acid tryptophan. Tryptophan is a normal part of the human diet. Tryptophan gets metabolized/changed to other chemicals in the body- including KYNA. By giving people 6 grams of tryptophan, the investigators will be able to increase the KYNA level in a controlled way. The investigators will then be able to study the effects of KYNA on neurotransmitters by using cognitive tests and magnetic resonance imaging techniques (measuring brain activity and brain chemistry using the MRI magnet). The overall goal of the study is to examine how the medication N-acetylcysteine (NAC), when added to tryptophan, affects various cognitive functions, such as verbal and visual memory. The investigators will also use magnetic resonance imaging (MRI) to examine how NAC affects brain activity and chemicals.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesUnited States
Collaborators--

Timeline

Phase 2CompletedFinished
2020202120222023202420252026
First PostedJul 9, 2019
Enrollment StartJan 20, 2020
Primary CompletionAug 14, 2024
TodayJul 2, 2026
Enrollment to primary: 4.6 yearsPosted 7.0 years ago

Interventions

N-acetylcysteine (NAC)drug

Flavored effervescent formulation

Placebodrug

Flavored effervescent formulation designed to mimic NAC

Tryptophandrug

Oral slurry form