NCT04520178

Brief Summary

This study will assess how the serotonin precursor, 5-HTP, alter nervous system excitability and motor function in individuals with spinal cord injuries of differing chronicity and severity. Participants will visit the lab on 4 separate occasions where they will be administered four different drugs in a randomized, double-blinded, placebo-controlled crossover design.

Trial Health

80
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
30

participants targeted

Target at P25-P50 for phase_2

Timeline
8mo left

Started Jul 2020

Longer than P75 for phase_2

Geographic Reach
2 countries

2 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress90%
Jul 2020Dec 2026

Study Start

First participant enrolled

July 1, 2020

Completed
2 months until next milestone

First Submitted

Initial submission to the registry

August 17, 2020

Completed
3 days until next milestone

First Posted

Study publicly available on registry

August 20, 2020

Completed
5.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 30, 2026

Expected
6 months until next milestone

Study Completion

Last participant's last visit for all outcomes

December 30, 2026

Last Updated

August 27, 2025

Status Verified

August 1, 2025

Enrollment Period

6 years

First QC Date

August 17, 2020

Last Update Submit

August 20, 2025

Conditions

Spinal Cord Injuries

Outcome Measures

Primary Outcomes (4)

  • Change in motoneuron excitability

    F waves

    Pre drug-intake, 30minutes, 60minutes, 90minutes and 120minutes post drug-intake

  • Change in spinal excitability

    H reflex

    Pre drug-intake, 30minutes, 60minutes, 90minutes and 120minutes post drug-intake

  • Change in flexor reflex/spasms

    Cutaneomuscular reflex

    Pre drug-intake, 30minutes, 60minutes, 90minutes and 120minutes post drug-intake

  • Change in functional movement performance

    Leg cycling task

    Pre drug-intake, 120-150minutes post drug-intake

Secondary Outcomes (4)

  • Serum analysis of 5HIAA (UofL Cohort only)

    90-120minutes post drug-intake

  • Serum analysis of serotonin (UofL Cohort only)

    90-120minutes post drug-intake

  • Serum analysis of cortisol (UofL Cohort only)

    90-120minutes post drug-intake

  • Whole blood analysis of Serotonin (UofL Cohort only)

    90-120minutes post drug-intake

Study Arms (4)

Low-dose 5HTP

ACTIVE COMPARATOR

50mg 5-HTP in combination with 50mg carbidopa

Drug: 5-HydroxytryptophanDrug: Carbidopa

High-dose 5HTP

ACTIVE COMPARATOR

100mg 5-HTP in combination with 50mg carbidopa

Drug: 5-Hydroxytryptophan 100 MGDrug: Carbidopa

Carbidopa

SHAM COMPARATOR

50mg carbidopa only

Drug: Carbidopa

Placebo

PLACEBO COMPARATOR

Placebo comparator

Drug: Placebo

Interventions

5-Hydroxytryptophan 100 MGDRUG

100mg combined with 50mg carbidopa

High-dose 5HTP
5-HydroxytryptophanDRUG

50mg combined with 50mg carbidopa

Low-dose 5HTP
CarbidopaDRUG

50mg

CarbidopaHigh-dose 5HTPLow-dose 5HTP
PlaceboDRUG

Placebo

Placebo

Eligibility Criteria

Age18 Years - 65 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • participants must have suffered trauma to the spinal cord at least six months ago or longer

You may not qualify if:

  • individuals with damage to the nervous system other than to the spinal cord
  • pregnant and/or breastfeeding women
  • alcoholic participants
  • history of seizure/epilepsy
  • history of suicidal thoughts or behaviors
  • known or suspected allergy to the medication ingredients
  • cardiovascular disease including history of heart attack or heart rhythm irregularities
  • coronary artery disease
  • reduced liver function or disease
  • reduced kidney function or disease
  • lung disease
  • comatose or depressed states due to CNS depressants
  • endocrine dysfunction
  • blood dyscrasias or blood related disease
  • bone marrow depression
  • +21 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (2)

University of Louisville

Louisville, Kentucky, 40292, United States

COMPLETED

University of Alberta

Edmonton, Alberta, T6G-2E1, Canada

RECRUITING

MeSH Terms

Conditions

Spinal Cord Injuries

Interventions

5-HydroxytryptophanCarbidopa

Condition Hierarchy (Ancestors)

Spinal Cord DiseasesCentral Nervous System DiseasesNervous System DiseasesTrauma, Nervous SystemWounds and Injuries

Intervention Hierarchy (Ancestors)

TryptophanAmino Acids, AromaticAmino Acids, CyclicAmino AcidsAmino Acids, Peptides, and ProteinsMethyldopaDihydroxyphenylalanineCatecholaminesAminesOrganic ChemicalsHydrazinesCatecholsPhenolsBenzene DerivativesHydrocarbons, AromaticHydrocarbons, CyclicHydrocarbons

Study Officials

  • Jessica D'Amico, PhD

    University of Alberta

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Jessica D'Amico, PhD

CONTACT

780-735-7917damico1@ualberta.ca

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, OUTCOMES ASSESSOR
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 17, 2020

First Posted

August 20, 2020

Study Start

July 1, 2020

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

December 30, 2026

Last Updated

August 27, 2025

Record last verified: 2025-08

Locations

US(1)CA(1)