While life-saving, many cancer chemotherapy drugs come with serious side effects. These include hearing-related side effects such as hearing loss, tinnitus (ringing in your ears), and balance problems. While sometimes these side effects are temporary and get better after treatment ends, often they’re permanent.
If you’re about to undergo cancer treatment—here’s what you need to know.
Oncologists have known the risk for decades when using certain chemotherapy drugs. However, in the past few years, doctors have become more sensitive to the effects of specific cancer treatments.
Many successful chemo drugs are ototoxic, which means “poisoning of the ears.” Some drugs destroy the tiny hairs in the cochlea, which transcend sound. Other drugs attack structures of the ear, such as the cochlea, or block sounds to the auditory nerve.
One chemo drug commonly known to be poisonous to the ears is Cisplatin. Many chemo patients have a compromised immune system and use other common medications known to be dangerous such as the “mycin” family, including Neomycin, Tabromycin, Erythromycin, and Vancomycin.
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as Ibuprofen and Naproxen can damage the ears, although if they are discontinued, the effects are usually reversible.
Cancer treatment typically relies on a trio of treatment options: radiation, surgery, and chemotherapy, often performed in conjunction—for instance, a person may have surgery followed by a course of radiation and chemotherapy.
All three cancer treatment options have the potential to damage hearing, depending on the location of cancer.
Radiation
During radiation treatment, high-energy waves or particles destroy or damage cancer cells. However, if radiation is needed anywhere in the head and neck, it can potentially lead to two types of hearing loss:
Conductive hearing loss, a type of hearing loss that happens when the sound doesn’t make its way to the inner ear, may occur. This is due to ear canal narrowing, eardrum thickening, or other ear changes caused by radiation, according to a 2019 article published in the Journal of Neurologic Surgery. According to the article, a condition called otitis media with effusion (OME), where fluid collects in the middle ear, occurs in nearly half of the people who have radiation therapy in the head and neck.
Sensorineural hearing loss, which arises with damage to the inner ear or auditory nerve, can also occur due to radiation. According to the journal article, higher doses of radiation are more likely to cause hearing loss. People under age three and over 50 are at a higher risk for this type of hearing loss, as are people being treated with chemotherapy cisplatin (more on that in a moment). This type of hearing loss is permanent.
Chemotherapy and Hearing Loss
Chemotherapy refers to the use of powerful chemicals that are capable of killing cancer cells. In some cases, chemotherapy drugs can be “ototoxic,” which means they harm hearing.
About half of all patients who receive the chemotherapy drug cisplatin develop hearing-related side effects, including hearing loss, tinnitus, and vertigo. This is known as ototoxicity.
Platinum-Based Chemotherapy (Cisplatin)
This is especially the case for chemotherapy, known as platinum-based therapy (chemo meds containing platinum). According to a review article in Cancer Chemotherapy and Pharmacology, the most ototoxic platinum-based chemotherapy is Cisplatin. According to the National Cancer Center, this medication treats bladder, testicular, and ovarian cancer. Hearing loss, tinnitus, and imbalance are common in patients who receive platinum-based chemotherapy and can cause debilitating effects.
Hearing-related side effects to this medication appear fairly common: Permanent hearing loss occurs in about half of all patients who take Cisplatin, ASHA notes. In addition, it usually causes high-frequency hearing loss.
Scientists are still working to understand why cisplatin damages hearing—it may be because it quickly enters the inner ear (while other drugs are blocked) but doesn’t seem to exit it, according to ASHA. Once in the inner ear, the medications may cause damage to hair cells, which are vital to the hearing process.
The Vital Role Of The Pharmacist
If you’ve experienced or are concerned that a cancer drug is ototoxic and threatens to harm your hearing, your pharmacist can provide exact start dates and the dates of increased dosage. Once a timeline has been established when the drug was dispensed (or increased), and the ear-related side effect, the audiologist, and pharmacist are in a unique position to work together in helping the patient understand and manage their hearing loss. They can then present the information to the prescribing physician for possible medical management.
Audiometric Testing And Monitoring
An audiological evaluation is usually scheduled before administering any known ototoxic chemotherapy drug. Follow-up protocols already exist from the American Academy of Audiology (AAA).
An audiologist will evaluate hearing and help differentiate between certain types of losses—some of which could be medically or surgically correctable. However, the medication could aggravate the condition if there is pre-existing hearing loss. Therefore, information from the pharmacist is critical to determine if the tinnitus is an adverse event or if the hearing loss is getting worse.
Audiologists will have an ototoxic drug monitoring protocol based on current research.
Summary
Monitoring Hearing Loss After Chemotherapy
Talking to your doctor about any treatment’s potential risks and benefits is essential to feel informed and confident about your plan.
If you begin treatment with an ototoxic medication, it’s essential to continually monitor your hearing health and look for signs of hearing loss. Before starting treatment, schedule a hearing test to establish a baseline of your hearing and balance systems. Then, during treatment, it’s a good idea to schedule periodic hearing tests to stay on top of any changes to your hearing that may be happening slowly and subtly.
Be sure to look out for any noticeable changes to your hearing. Symptoms of early hearing loss include the inability to understand specific sounds, missing parts of conversations, trouble hearing in crowds, and hearing ringing in your ears. With the hearing loss that appears to be due to the prescribed drugs for cancer treatment, you should consult your pharmacist, audiologist, and physician to make the best possible decision for your health and hearing.
REFERENCES
Cancer Treatment Centers of America
Miracle-Ear
Cure Today
Healthy Hearing
Hearing Tracker
