Cisplatin, a commonly used chemotherapy for solid tumors can cause side-effects of hearing loss in patients, that can be permanent. A recent study tested the interaction of Cisplatin chemotherapy with caffeine consumption in a rat model and found that caffeine use during Cisplatin treatment worsened Cisplatin induced hearing loss. Cancer patients on Cisplatin chemotherapy should be cautioned against the use of caffeine.
Cisplatin is a highly effective, commonly used chemotherapy to treat solid tumors. However, Cisplatin chemotherapy unfortunately also leads to severe side-effects including hearing loss and kidney toxicity. Unlike some side-effects that reverse once the treatment is stopped, the hearing loss can be permanent and can have a significant impact on the quality of life of the cancer survivor. Before we understand how Cisplatin causes the hearing loss (ototoxicity), we need to understand the anatomy of the ear.
The parts of the ear that most people are familiar with is the outer ear and ear drum but other key parts include the ossicles in the middle ear, cochlea, and basilar membrane, part of the inner ear. Essentially, sound is just produced by a vibration of objects and these vibrations are transmitted by the ear drum from the air to the ossicles and cochlea inside the ear. The cochlea is responsible for breaking down all of the different pitches that make up sound and it does this through the basilar membrane which is located inside the cochlea. So when new sounds are transmitted from the ear drum, hair cells in the basilar membrane will wiggle based on their specific frequencies which will lead to the activation of neural signals leading to the brain. Hence, people wearing hearing aids are only amplifying the sound going into the ear but are unable to replace the damaged cells inside the cochlea.
Cisplatin can enter cells in the cochlea and is retained there for months and years. Cisplatin can cause damage to the cells in the basilar membrane and cause inflammation and death of the hair cells, thus resulting in permanent hearing loss. (Rybak LP et al, Semin Hear., 2019) Cells in Cochlea have adenosine receptors that when activated, can protect from damage to these cells and the corresponding hearing loss. In a recently published study in 2019, scientists have found that commonly used substances such as caffeine, found in coffee and various energy and carbonated drinks, that can inhibit these adenosine receptors, when consumed during Cisplatin chemotherapy treatment, has the potential to worsen the hearing loss side-effect.
Caffeine & Cisplatin chemotherapy-induced Hearing Loss
In this study done by researchers from Southern Illinois University in the United States, tested the hypothesis that caffeine can exacerbate the effects that Cisplatin had on patients who were starting to permanently lose their hearing due to the therapy. This hypothesis they tested in a rat model of cisplatin ototoxicity administered caffeine orally. They found that a single dose of caffeine worsened cisplatin-induced hearing loss without damage to the outer hair cells but increased inner ear inflammation. But multiple doses of caffeine also caused damage to the hair cells in the cochlea besides causing inflammation. The action of caffeine they determined was due to inhibition of the adenosine receptors in the cells of the cochlea. (Sheth S et al, Sci Rep. 2019)
In conclusion, the findings from this study indicate a possible drug-drug interaction between caffeine and cisplatin-induced hearing loss. Therefore, cancer patients on cisplatin containing chemotherapy regimens should be cautioned about the use of coffee and other caffeinated drinks. Avoiding caffeine during Cisplatin chemotherapy treatment may not stop or reverse the impending loss of hearing, but at least it will not further worsen and speed up the process either. Patients on Cisplatin therapy starting to experience hearing loss must inform their doctors immediately for possible dose reduction strategies and stay off from all forms of caffeine.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer.Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.