Acute Nicotine Gum and Tinnitus Loudness in Non-Smoking Adults

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.

Inclusion Criteria: * 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 Exclusion Criteria: * Current or recent tobacco or nicotine use * Pregnancy or breastfeeding * Unstable cardiovascular disease * Any condition precluding the psychoacoustic tasks