SPI-1005 for Prevention and Treatment of Tobramycin Induced Ototoxicity

Inclusion Criteria: * Cystic fibrosis patients about to receive IV tobramycin for acute pulmonary exacerbation. * Voluntarily consent to participate in the study. * Females of childbearing potential should be using and committed to continue using one of the following acceptable birth control methods: * Sexual abstinence (inactivity) for 14 days prior to screening through study completion; or IUD in place for at least 3 months prior to study through study completion; or Barrier method (condom or diaphragm) with spermicide for at least 14 days prior to screening through study completion; or Stable hormonal contraceptive for at least 3 months prior to study through study completion. * Ability to perform all behavioral tests as indicated. Exclusion Criteria: * Current use or within 60 days prior to study enrollment the following IV ototoxic medications: aminoglycoside antibiotics (gentamicin, tobramycin, amikacin, streptomycin); platinum-containing chemotherapies (cisplatin, carboplatin, oxaliplatin); or loop diuretic (furosemide). * History of idiopathic sensorineural hearing loss, otosclerosis, or vestibular schwannoma. * History of middle ear or inner ear surgery. * Current conductive hearing loss or middle ear effusion. * Significant cardiovascular, hepatic, renal, hematologic, endocrine, immunologic, or psychiatric disease. * History of hypersensitivity or idiosyncratic reaction to compounds related to ebselen. * Participation in another investigational drug or device study within 30 days prior to study enrollment. * Female patients who are pregnant or breastfeeding.