Study of Lamotrigine to Treat Ménière's Disease

Inclusion Criteria: * Male and female participants aged 18 years or older * Diagnosed with unilateral definite Ménière's disease according to the AAO-HNS 1995 criteria, confirmed by an ENT * Active vertigo: at least two Ménière's vertigo attacks (defined as lasting 20 minutes or longer and associated with tinnitus, ear fullness, or low frequency hearing loss and nausea/vomiting) every four weeks during the eight-week qualification period and at least two more Ménière's vertigo attacks during the lead-in phase prior to randomization * Documented unilateral lower frequency hearing loss defined as the four-tone average (arithmetic mean rounded to the nearest whole number) of the pure-tone thresholds at 0.25, 0.5, 1 and 2 kilohertz (kHz) more than or equal to 25 decibels (dB) of the worse audiogram during the six months before screening * Have tried diuretics for at least one month and discontinued treatment due to continued vertigo attacks * All other co-existing medical or psychiatric conditions are stable, and no greater than moderate severity * Willing to avoid pregnancy during the entirety of the study (abstinence or two forms of acceptable birth control, such as condoms and oral contraceptives) Exclusion Criteria: * Bilateral Ménière's disease * Current or past history of migraine * Any other neuro-otologic disease or major vestibular abnormality found during screening that could confound the evaluation of Ménière's symptoms * Previous intolerance or sensitivity to lamotrigine * On any prohibited medication within four weeks prior to the study * History of tympanostomy tubes with evidence of perforation or lack of closure * IT gentamicin injections or endolymphatic sac surgery within the last year * History of or current immunodeficiency disease, nephrolithiasis, hypertension, cardiac disease, arrhythmia, hypercholesterolemia, hemiplegic/basilar migraine, stroke, diabetes, vascular disease or kidney disease * Family history of unexplained deafness * Pregnant or breastfeeding * Current diseases or conditions that may be associated with an altered perception of processing stimuli * Current severe medical condition(s) that in the view of the investigator prohibits participation * Previously used the investigational drug * Current non-vertiginous dizziness (orthostatic or panic disorder) unless it could be clearly differentiated from Ménière's attacks by the participant