Drugs Affecting the Inner Ear

Abstract

Many drugs have a site of action within the inner ear. The list includes therapeutic, diagnostic and ototoxic agents. Therapeutic agents are most useful in cases of infections, endolymphatic hydrops, vascular insufficiency, vertigo of peripheral origin, autoimmune disease, otosclerosis (otospongiosis), sudden hearing loss and tinnitus. For infections, the most widely used anti-microbial agents are the penicillins and cephalosporins. There are no antiviral agents that have been proven useful for inner ear viral infections. However, steroids have been of some value for controlling some of the sequelae. Steroids have also been useful in conjunction with ampicillin in cases of syphilitic hearing loss. In cases of endolymphatic hydrops, the diuretics chlorthalidone, hydrochlorothiazide and acetazolamide have been useful. When diuretic and diet therapy cannot control endolymphatic hydrops, ototoxic drugs such as streptomycin have been used. In cases of vascular insufficiency within the inner ear, vasodilators such as carbon dioxide, papaverine, buphenine (nylidrin), naftidrofuryl (nafronyl) and thymoxamine have been recommended, but their true efficacy is questionable. Some success with betahistine has been achieved but the mechanism of this drug's action may be other than vasodilatation. Vertigo is best controlled with antihistamines and anticholinergics and with certain calcium channel blockers. Autoimmune inner ear disease appears to respond to a combination of steroids and cyclophosphamide. Although controversial, current pharmacotherapy for otosclerosis includes sodium fluoride. Sudden hearing loss is treated with a 'shotgun' combination of drugs and/or bed rest. There are as yet no drugs which can be used to routinely reduce tinnitus although some medications may help the patient tolerate the problem. Lignocaine (lidocaine) is useful in diagnosing, and very evanescently reducing, tinnitus. Glycerin (glycerol) is useful in diagnosing endolymphatic hydrops and may at times transiently reduce tinnitus. The drugs most noted for their ototoxicity are the aminoglycoside antibiotics, certain diuretics, non-steroidal anti-inflammatory agents, certain anticancer agents and some miscellaneous chemicals. Some new research drugs are in clinical trials for tinnitus, hearing loss and vertigo, and the rational search for new otopharmacotherapeutic agents is increasing.

Betahistine Increases Vestibular Blood Flow

“…Many pathologic conditions are proposed to contribute to various vestibulopathies, including the interruption of inner ear blood flow regulation. [1][2][3] Dysfunctional vestibular blood flow (VBF) is thought to contribute to such vestibular disorders as acute vestibular vertigo, Meniere's disease, and motion sickness. The literature reveals an assortment of treatment modalities for vestibular disorders of suspected vascular insufficiencies including administration of betahistine (BH).…”

The Association Between Dehydration and the Prognosis of Sudden Sensorineural Hearing Loss

“…Systemic or intratympanic steroid therapy is widely used for the treatment of SSNHL, as steroids are known to be efficacious regarding the inner ear in cases with hearing loss of viral, vascular, autoimmune, endolymphatic hydrops, and other etiologies ( 25 , 26 ). Steroids also exert mineralocorticoid effects, promoting the reabsorption of sodium and water.…”

A Case Report of Sudden Sensorineural Hearing Loss (SSNHL) After Administration of the COVID-19 Vaccine

“…5 The treatment regimen was started in our patient and previous reports as corticosteroids are known to have sites of action in the inner ear in viral, vascular, syphilitic, autoimmune, endolymphatic hydrops (Meniere's disease), and other etiologies of hearing loss. 25,26 Subsequently, intratympanic corticosteroids for salvage therapy were recommended as the patient had incomplete recovery from SSNHL 2 to 6 weeks after onset of symptoms. 17 Additional treatment options that could potentially have been explored was the use of the combination of hyperbaric oxygen therapy (HBOT) combined with corticosteroid therapy within 2 weeks of onset of SSNHL.…”