Acute Nicotine Gum and Tinnitus Loudness in Non-Smoking Adults

NCT07772089 | Completed Phase 1 FDA Drug

• 2 other identifiers: IRB-25-0430SEED Grant 2026
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

This study tested whether a single dose of nicotine gum can reduce the loudness of tinnitus (ringing in the ears) in non-smoking adults with chronic tinnitus. Nicotine acts on brain nicotinic acetylcholine receptors that regulate the balance of excitation and inhibition in auditory and attention networks, and may temporarily quiet the phantom sound while improving the ability to focus on relevant sounds. Using a double-blind, placebo-controlled, within-subject crossover design, each participant attended two sessions and received a single 4 mg dose of nicotine polacrilex gum at one session and a flavor-matched placebo gum at the other, in random order. The primary measure was the within-session change in a psychoacoustic match of tinnitus loudness; auditory selective attention was a secondary measure.

Conditions

Tinnitus; Chronic Subjective Tinnitus

Keywords

Tinnitus; Nicotine; Nicotinic acetylcholine receptor; Selective attention; Nicotine polacrilex gum

Outcome Measures

Primary Outcomes (1)

• Within-session change in psychoacoustic tinnitus loudness match (nicotine vs placebo)

  Tinnitus loudness was matched to the participant's tinnitus pitch by a method-of-adjustment procedure and expressed in dB sensation level. The pre-to-post change was compared between the nicotine and placebo sessions.

  Baseline (pre-administration) and up to 2 hours after gum administration

Secondary Outcomes (1)

• Auditory selective attention after administration (Coordinate Response Measure percent correct), nicotine vs placeb

  Up to 2 hours after gum administration

Other Outcomes (3)

• Tinnitus Handicap Inventory (THI) score

  Baseline (first session, before administration)

• Tinnitus Functional Index (TFI) score

  Baseline (first session, before administration)

• Pure-tone audiometry (0.25-12 kHz)

  Baseline (first session, before administration)

Study Arms (2)

Nicotine gum (4 mg)

EXPERIMENTAL

Single 4 mg dose of nicotine polacrilex gum, chewed for 20 minutes at 1 Hz using the standardized administration protocol.

Drug: Nicotine polacrilex gum 4 mg

Placebo gum

PLACEBO COMPARATOR

Flavor-, color-, shape-, and texture-matched placebo gum, chewed under the identical protocol.

Other: Placebo gum

Interventions

Nicotine polacrilex gum 4 mg DRUG

A single 4 mg dose (one 4 mg piece) of mint nicotine polacrilex gum, chewed continuously for 20 minutes at one chew per second with saliva retained.

Also known as: Nicorette

Nicotine gum (4 mg)

Placebo gum OTHER

Flavor-matched sugar-free mint gum (Trident) matched to the nicotine gum in shape, flavor, color, and texture, chewed under the identical protocol.

Placebo gum

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Non-smoking adult, defined as fewer than 100 cigarettes in a lifetime and none in the past year, with a Fagerstrom Test for Nicotine Dependence score of 2 or less and a negative urinary cotinine test
• Chronic subjective tinnitus of at least 6 months' duration

You may not qualify if:

• Current or recent tobacco or nicotine use
• Pregnancy or breastfeeding
• Unstable cardiovascular disease
• Any condition precluding the psychoacoustic tasks

Sponsors & Collaborators

• San Diego State University: lead

Study Sites (1)

San Diego State University

San Diego, California, 92182, United States

Location

MeSH Terms

Conditions

Tinnitus

Interventions

Nicotine Chewing Gum

Condition Hierarchy (Ancestors)

Hearing Disorders; Ear Diseases; Otorhinolaryngologic Diseases; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Chewing Gum; Plant Gums; Biopolymers; Polymers; Macromolecular Substances; Polysaccharides; Carbohydrates; Tobacco Use Cessation Devices; Therapeutics; Candy; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Xianhui Wang

  San Diego State University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Participants and the assessors who administered the outcome measures were masked to session assignment. Masking was supported by a flavor-, color-, shape-, and texture-matched placebo gum, independent gum preparation, and a blindfold during administration.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Single-dose, two-period crossover: each participant received a single 4 mg dose of nicotine polacrilex gum in one session and a flavor-matched placebo gum in the other, in randomized order, with at least 72 hours between sessions.

Study Record Dates

• First Submitted: August 12, 2026
• First Posted: August 19, 2026
• Study Start: March 25, 2026
• Primary Completion: August 3, 2026
• Study Completion: August 3, 2026
• Last Updated: September 4, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: Beginning with publication of the primary results article; available indefinitely thereafter.
• Access Criteria: Open access. The data will be publicly available without restriction, to any user and for any purpose, without investigator support and without a data access agreement or proposal approval.

Locations

US (1)