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Intratympanic gentamicin was originally introduced as a treatment option for Meniere's disease in 1957 but fell out of favor due to the high incidence of sensorineural hearing loss which resulted from the chemical destruction of the labyrinth. Gentamicin is typically the drug used (may also be streptomycin) and is extremely toxic to the organs of the inner ear. Despite this significant side effect, one of the biggest advantages of intratympanic delivery was that the body is not exposed to systemic side effects of the medication, including destruction of the vestibular system and auditory organs of the contralateral ear.

Intratympanic gentamicin has recently made a comeback as an effective treatment option for Meniere's disease due to the new system of administration, namely titration of the drug where the dose is given in low-dose installments and adjusted for maximum effect. Thus the destruction of the labyrinth is gradual and can be discontinued at any time. The result of this new protocol for delivery of gentamicin is that it achieves excellent control of vertigo with considerably lower incidence of hearing loss. In addition, hearing loss can be monitored so that treatment can be suspended at the first sign of hearing loss.

Candidates for intratympanic gentamicin include patients with the following conditions:

• Unilateral Meniere's disease
• Willing to risk increased hearing loss
• Severe, unremitting vertigo that has not responded to prior medical therapy

Initially, a tube is surgically placed through the tympanic membrane. For administration of the gentamicin, the patient lays down on their back on the treatment table with their head turned towards the good ear. The medication is injected through the tube and the patient remains lying down for 30 minutes during which time the medication is absorbed into the inner ear through the oval window membrane that separates the middle and inner ear. Any extra medication remaining in the ear canal is then aspirated. The ear must be kept dry for two weeks.

Follow up visits begin 3-4 weeks after the first injection. While most patients report varying degrees of relief from vertigo symptoms after one injection and do not need more, some patients may require repeated injections to achieve an acceptable reduction of symptoms. Patients are generally offered the injection 6-10 times before the treatment is considered a failure. All aspects of inner ear function, namely hearing (audiogram), balance, nystagmus, and motion intolerance must be monitored carefully and frequently at each follow-up appointment to detect any signs of complications. Gentamicin injections are discontinued at the first sign of:

• Hearing loss
• Control of vertigo
• Reduced vestibular function (loss of balance)

Complications of intratympanic gentamicin include:

• Bleeding
• Infection
• Eardrum perforation with need for later repair
• Hearing loss (up to 30% of patients)
• Worsening of word recognition (up to 30% of patients)
• Change or loss of sense of taste
• Persistent balance problems
• Facial paralysis (least likely to happen with this procedure compared to other surgical procedures for Meniere's)

Intratympanic gentamicin is the least invasive procedure for intractable vertigo. Some surgeons consider it as a procedure to be explored after unsuccessful endolymphatic sac surgery but before other ablative surgery, while other surgeons report that patients who have had prior endolymphatic sac surgery may not respond as well to intratympanic gentamicin as those who have not undergone that procedure possibly due to changes in the membranes of the inner ear. There are also surgeons who recommend intratympanic steroids (described above), which is a nondestructive treatment, before offering intratympanic gentamicin that ultimately is guaranteed to destroy some or all of the labyrinth.