Adults 18 to 65, any sex, with COVID-19 or Olfactory Disorder. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Clinical Global Impression of Improvement Scale (CGI-I)Primary· After the 8 week FD phase and four week post-tapper
The primary outcome measure was the treatment response rate following the 8-week FD phase as determined by the CGI-I. The CGI-I is a modified 7-point Likert scale of -perceived change.
Response options include: (1) much better, (2) somewhat better, (3) slightly better), (4) neither better nor worse, (5) slightly worse, (6) somewhat worse, (7) much worse. The response rate was defined as the number of participants self-reporting at least "slightly better" divided by the number of participants in each treatment group. Th
Fixed Dose Period
Group
Value
95% CI
Gabapentin
8
Placebo
20
4 week post tapper
Group
Value
95% CI
Gabapentin
7
Placebo
12
University of Pennsylvania Smell Identification Test (UPSIT)Secondary· Baseline, after completion of eight-week fixed-dose period, and 4 weeks after completion of taper-down period
Forty different odors are presented in this test.
Scoring: Forced choice of 4 responses to identify each smell. Anosmia: score 6-18; severe microsmia: score 19-25, moderate microsmia: 26-30 in women and 26-29 in men; mild microsmia: 31-34 in women and 30-33 in men; and normosmia: score \> 34 in women and \>33 in men.
The total UPSIT score can range from 0 to 40 and scores. The MCID in UPSIT score is 4.
Scores are interpreted as the level of absolute smell function (i.e., normosmia, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia), using the age- and sex-related normative clas
Baseline
Group
Value
95% CI
Gabapentin
23
10 – 31
Placebo
24
7 – 34
Fixed Dose
Group
Value
95% CI
Gabapentin
25
12 – 34
Placebo
25
15 – 34
Post-taper
Group
Value
95% CI
Gabapentin
26
7 – 33
Placebo
25
9 – 35
Olfactory Dysfunction Outcomes Rating (ODOR)Secondary· Baseline, after completion of eight-week fixed-dose period, and 4 weeks after completion of taper-down period
The ODOR questionnaire is a validated 28-item patient-reported outcome measure which assesses the physical, functional, and emotional consequences of OD.
The ODOR is a 28-item instrument with each item scored as either no difficulty or very rarely bothered (0) to complete difficulty or very frequently bothered (4) with a total instrument score range of 0 to 112 points. Higher scores indicate higher degree of dysfunction and limitation. the MCID is 15 points.
Baseline
Group
Value
95% CI
Gabapentin
23
10 – 31
Placebo
54.5
30 – 96
Fixed Dose
Group
Value
95% CI
Gabapentin
25.5
15 – 34
Placebo
49.9
8 – 96
Post Taper
Group
Value
95% CI
Gabapentin
25
9 – 35
Placebo
45
8 – 85
NASAL-7Secondary· Baseline, after completion of eight-week fixed-dose period, and 4 weeks after completion of taper-down period
NASAL-7 is a simple diagnostic tool for olfactory dysfunction that is based on commonly found household items and can be used by adults who suspect olfactory dysfunction. The NASAL-7 was developed by Dr. Piccirillo and colleagues in the Clinical Outcomes Research Office. The NASAL-7, contains 7 household items with each item scored as 0 for 'Cannot Smell', 1 for 'Smells Less Strong/Different Than Normal', and 2 for 'Smells Normal', for a total possible score ranging from 0-14. The following four categories of olfactory function were defined based on NASAL-7 score: anosmia (score 0-4), severe d
Baseline
Group
Value
95% CI
Gabapentin
6
Placebo
10
Gabapentin
8
Placebo
12
Gabapentin
2
Placebo
3
Gabapentin
2
Placebo
1
Fixed Dose
Group
Value
95% CI
Gabapentin
4
Placebo
7
Gabapentin
5
Placebo
9
Gabapentin
4
Placebo
6
Gabapentin
5
Placebo
4
Post taper
Group
Value
95% CI
Gabapentin
5
Placebo
7
Gabapentin
6
Placebo
6
Gabapentin
2
Placebo
5
Gabapentin
3
Placebo
7
CGI-Severity of SmellSecondary· 8-week Fixed-Dose period, and 4 weeks after completion of Taper-Down phase
CGI-Severity. The CGI-Severity scale ranges from 1 to 7, where 1 is normal function and 7 is complete anosmia. This assessment will provide subjective data on patients' baseline olfactory function prior to beginning the trial, after 8-week Fixed-Dose period, and 4 weeks after completion of Taper-Down phase
Assessments of the Secondary Outcome Measures of Study Groups: Baseline
Group
Value
95% CI
Gabapentin
4
Placebo
4
Gabapentin
12
Placebo
16
Gabapentin
1
Placebo
4
Gabapentin
1
Placebo
1
Fixed Dose
Group
Value
95% CI
Gabapentin
3
Placebo
5
Gabapentin
4
Placebo
13
Gabapentin
8
Placebo
4
Gabapentin
3
Placebo
3
Post taper
Group
Value
95% CI
Gabapentin
2
Placebo
3
Gabapentin
7
Placebo
13
Gabapentin
5
Placebo
6
Gabapentin
2
Placebo
2
CGI-S of ParosmiaSecondary· 8-week Fixed-Dose period, and 4 weeks after completion of Taper-Down phase
Clinical Global Impression-Severity Scale for Parosmics (CGI-P). The CGI-P Scale is a global rating of parosmia and the single global rating ranges from 1-5, where 1 is No Distortion, 2 is Mild Distortion, 3 is Moderate Distortion, 4 is Mostly Distorted, and 5 is Complete Distortion. The response on the CGI-P will provide information on the patient's perceived severity of the distortion of their smell.
Assessments of Secondary Outcome Measures of Study Groups: Baseline
Group
Value
95% CI
Gabapentin
7
Placebo
6
Gabapentin
9
Placebo
8
Gabapentin
2
Placebo
7
Gabapentin
0
Placebo
4
Fixed Dose
Group
Value
95% CI
Gabapentin
2
Placebo
3
Gabapentin
6
Placebo
6
Gabapentin
4
Placebo
9
Gabapentin
5
Placebo
7
Post tapper
Group
Value
95% CI
Gabapentin
2
Placebo
2
Gabapentin
5
Placebo
9
Gabapentin
6
Placebo
9
Gabapentin
2
Placebo
4
Adverse events — posted to ClinicalTrials.gov
Time frame: If tolerated, all participants will complete the Titration period (≤ 4 weeks), Fixed-Dose period (8 weeks), and Taper-Down period (2 weeks) for maximum 14 weeks of active participation. In addition, there will be a 4-week, post-Taper completion follow-up for maximum total of 18-week trial duration.
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
This study will investigate the efficacy of oral gabapentin in olfactory improvement following Covid-19- associated olfactory dysfunction. This is a randomized, double-blinded, placebo-controlled trial.
Publications & conference data
3 peer-reviewed publications reference this trial (live from Europe PMC):
NCT07183709 — Safety and Immunogenicity Trial of PepGNP-COVID19 Vaccine in Adults
· Phase 1
· active not recruiting
NCT07300839 — A Study to Learn About a COVID-19 Vaccine in Healthy Adults 50 Through 64 Years of Age
· Phase 3
· active not recruiting
NCT07221162 — A Safety and Immunogenicity Trial of Boost-2867 Vaccine, Via Intranasal and Intramuscular Routes
· Phase 1
· recruiting
NCT07215520 — Safety and Tolerability of a Newcastle Disease Virus-Based Mucosal COVID-19 Vaccine in Previously Vaccinated Adults
· Phase 2
· recruiting
NCT07222384 — A Study to Learn About BNT162b2 (LP.8.1)-Adapted Vaccine Against SARS-CoV-2 in Children 5 Through 11 Years of Age That A
· Phase 3
· active not recruiting
Other Washington University School of Medicine trials
Trials by the same sponsor.
NCT05521997 — Glutaminase Inhibition and Chemoradiation in Advanced Cervical Cancer
· Phase 2
· not yet recruiting
NCT07101666 — Total Neoadjuvant Therapy With Short Course Radiation Therapy in Gastric Cancer
· Phase 2
· not yet recruiting
NCT07200089 — Recombinant Human IL-7 (NT-I7) in Relapsed/Refractory Multiple Myeloma Following BCMA CAR-T Therapy (Cilta-cel)
· Phase 1
· not yet recruiting
NCT07313592 — Whole Genome Sequencing (ChromoSeq®) for Acute Lymphoblastic Leukemia (ALL) Patients
· not yet recruiting
NCT07419464 — 5-Fluorouracil Response and Optimization STudy (The FROST Trial)
· Phase 2
· not yet recruiting
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Washington University School of Medicine
Last refreshed: 4 March 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT05184192.