Ototoxicity: Symptoms, Diagnosis, Treatment Options and Prevention

Ototoxicity refers to damage to the inner ear caused by certain medications or chemicals. This damage can lead to issues, such as hearing loss, balance problems, or tinnitus (ringing in the ears). In some cases, the effects may be permanent.

In this article, we’ll cover everything you need to know about ototoxicity—from what it is, the common symptoms, how it’s diagnosed, available treatments, and how to prevent it. We’ll also share our answers to frequently asked questions about this topic.

• What is Ototoxicity?
• What are the Common Symptoms of Ototoxicity?
• What Medications Cause Ototoxicity?
• How is Ototoxicity Diagnosed?
• What are the Treatment Options for Ototoxicity?
• How to Prevent Ototoxicity
• FAQs about Ototoxicity

The word “ototoxicity” literally means “ear poisoning,” and it is sometimes referred to as drug-induced hearing loss. This condition occurs when certain medications or chemicals damage the inner ear, which controls hearing and balance.

These harmful substances can be found in medications or even in the environment (e.g. mercury, lead, or carbon monoxide). Patients receiving high-risk treatments, such as certain cancer or infection medications, should be closely monitored by hearing care professionals to catch any early signs of damage.

Ototoxicity can affect the cochlea (linked to hearing), the vestibular system (linked to balance), or both. Symptoms may occur suddenly or gradually, during or shortly after exposure to the ototoxic drug, and usually manifest in both ears.

Symptoms include:

• Tinnitus (ringing, buzzing, or hissing sounds in the ear)
• Hearing loss
• Oscillopsia, dizziness or vertigo
• Complications caused by hearing loss and/or imbalance (e.g. turning up the TV volume, frequent falls, etc.)

Several medications are known to cause ototoxicity, especially with prolonged use or high doses. Here are some common medication types associated with ototoxicity, but the list is non-exhaustive.

Ototoxicity is diagnosed through a combination of medical history, audiometry tests, and vestibular diagnostic tests. Early detection is key to reducing the risk of permanent damage, especially for patients undergoing treatment with high-risk medications.

Your doctor or hearing care professional will begin by asking questions about your current medications or recent treatments, symptoms, and overall health. This information helps determine whether ototoxicity is a likely cause of the symptoms.

Audiometry tests will be used to assess how well your ears and auditory system are functioning. Recommended tests may include Otoacoustic Emissions (OAE), Auditory Brainstem Response (ABR) and Extended High Frequency Pure Tone Audiometry test.

Vestibular tests, such as videonystagmography (VNG) or rotary chair testing, may be performed if dizziness or balance issues are present. This can help your doctor or hearing care professional localise the site of the lesion and determine the severity of the condition.

Treatment for ototoxicity focuses on preventing further damage, managing symptoms, and improving quality of life. Since ototoxicity can range from temporary to permanent and mild to severe, treatment plans vary depending on the cause, severity, and individual needs.

Your doctor or hearing care professional will recommend a treatment plan, but here’s a breakdown of the most common treatment options.

If a specific drug is causing ototoxicity, adjusting the medication is the first line of action when possible. Adjustments may include stopping the medication, substituting it, or reducing the dosage. While this doesn’t reverse the damage already caused, it helps prevent further damage.

Many ototoxic drugs are used for treating critical conditions such as cancer, so adjusting the medication may not be a viable option. In such instances, the following treatments may be recommended.

If the ototoxic drug has resulted in permanent hearing loss, hearing aids may be recommended to compensate for the loss of access to sounds. They work by amplifying sounds according to your hearing levels, giving you sufficient access to environmental sounds and speech for safety and ease of communication. 

Certain brands and models of hearing aids, such as Oticon, come with advanced technology and features that improve your overall listening experience. For example, Oticon’s BrainHearing technology reduces listening effort, while their 4D sensor technology (in Oticon Intent hearing aids) offers greater personalisation. Furthermore, most hearing aids come equipped with tinnitus masking features to help manage tinnitus symptoms.

Your hearing care professional will recommend the best hearing aid for you, depending on the degree of hearing loss, your symptoms and lifestyle needs.

In cases where ototoxicity has resulted in balance problems, Vestibular Rehabilitation Therapy (VRT) may be recommended. VRT is a form of physiotherapy designed to address the specific vestibular deficiency. It allows dizzy patients to habituate to their condition, thereby improving stability and confidence.

Preventing ototoxicity involves being proactive, especially if you’re taking medications known to affect hearing or balance. While not all cases can be completely avoided, there are steps you can take to lower your risk and catch potential problems early.

• Before starting on a new medication, ask your doctor if there’s any risk of hearing or balance side effects, and if there are safer alternatives.
• Before starting on a potentially ototoxic medication, take a baseline hearing test to have a clear starting point to track any changes during or after treatment.
• If you notice any changes in your hearing or balance, immediately inform your doctor.
• Take regular hearing tests to monitor changes in your hearing.
• Take medications only as directed and avoid changing doses without consulting your doctor.