Article by Hearing Partners, contributed by Jennifer Lee, Senior Clinical Audiologist at Hearing Partners
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, weโll cover everything you need to know about ototoxicityโfrom what it is, the common symptoms, how itโs diagnosed, available treatments, and how to prevent it. Weโll also share our answers to frequently asked questions about this topic.
What is 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.
What are the Common Symptoms of Ototoxicity?
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.)
What Medications Cause Ototoxicity?
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.
| Type of medication | Examples | Remarks |
|---|---|---|
| Over-the-counter (OTC) pain relievers | Typically only causes ototoxicity in high doses | |
| Certain antibiotics | ||
| Chemotherapy drugs | ||
| Some antimalarial and antifungal agents | Typically only causes ototoxicity after long-term usage | |
| Loop diuretics |
How is Ototoxicity Diagnosed?
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.
Medical history
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
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 diagnostic tests
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.
Suspect that you might be suffering from ototoxicity?
Early detection is crucial in preventing further damage. Speak to our hearing care professionals today about your symptoms.
What are the Treatment Options for Ototoxicity?
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 hereโs a breakdown of the most common treatment options.
Medication adjustments
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 doesnโt 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.
Hearing aids
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.ย
Certain brands and models of hearing aids, such as Oticon, come with advanced technology and features that improve your overall listening experience. For example, Oticonโs 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.
Balance therapy
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.
How to Prevent Ototoxicity
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 thereโs 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.
FAQs about Ototoxicity
Are children at risk of ototoxicity?
Yes, children can be at risk of ototoxicity, especially if theyโre taking medications for chronic infections or undergoing cancer treatment. Look for signs or symptoms that could signal hearing or balance issues, and see a doctor immediately if you suspect they could be suffering from ototoxicity.
How quickly does ototoxicity start?
Ototoxicity can start quickly or develop gradually, depending on several factors, including the type of medication, dosage, duration of exposure, and individual susceptibility. Symptoms can manifest within days, weeks or even months. Hence, monitoring your hearing health and balance through regular meetings with your doctor or hearing care professional is important for early detection.
Can over-the-counter medications cause ototoxicity?
Yes, some over-the-counter (OTC) medications like Aspirin can cause ototoxicity, especially when taken in high doses or over a long period of time. Itโs important to follow the dosage recommendations when using OTC medications.
Can ototoxicity be reversed?
No, the effects of ototoxicity are often irreversible. Thus, regular monitoring and early detection are essential in protecting your hearing and balance health.
Jennifer is a Senior Clinical Audiologist and the Team Lead at Hearing Partners. She has a Master of Science in Audiology from the National University of Singapore (NUS) and is experienced in diagnostic assessments for hearing and balance, aural rehabilitation, and paediatric hearing and CAPD assessment.