Pharmacological agents used for treatment and prevention in noise-induced hearing loss

In a review by Sakat and colleagues, pharmacological treatment options of noise-induced hearing loss (NIHL) were investigated. Both genetic and environmental factors are involved in NIHL, which is a preventable health problem. Prophylactic prevention of NIHL is primarily protective by nature, though there exist pharmaceutical interventions.

NIHL begins as high-frequency hearing loss, moving to loss of frequencies around 4000-6000 Hz, which proceeds to spread to both lower and higher frequencies, ending with loss at approximately 4000 Hz in the worst cases. NIHL is physiologically characterized by degeneration of hair cells, supporting cells, and eventually afferent nerve fibers. This thorough review of the literature reveals that the most commonly used agents for NIHL treatment are steroids, though antioxidants show promise as well, especially N-acetyl cysteine (NAC). The studies reviewed in this article indicare that NAC has been proven effective in both the protection against and treatment of NIHL.

Other promising pharmacological agents have been reported in animal studies, though further clinical studies are needed to determine their practical use. I think the findings of this review show potential for blossoming interprofessional collaboration between the worlds of pharmacy and audiology. Hopefully innovative pharmacological treatment will relieve many people of the burden of hearing devices and restore or, at the very least, prevent the loss of such a vital sense.

Sakat MS, Kilic K, Bercin S. Pharmacological agents used for treatment and prevention in noise-induced hearing loss. Eur Arch Otorhinolaryngol. doi:10.1007 (published 16 February 2016)

Influences of diabetes on hearing recovery in noise-exposed mice

Diabetes is a disease that affects the microvasculature. This in turn affects other systems of the body such as the renal, visual, and peripheral nervous systems. Many studies have focused on the effect of diabetes on hearing. Diabetes can interfere with the supply of blood to the cochlea or the 8th cranial nerve, causing degeneration. However, these studies have shown correlations between diabetes and hearing loss rather than causations according to a study published in the Journal of Audiology and Otology. This study specifically measured the effect of diabetes on the hearing of mice compared to that of normal mice. In order to measure the degree of hearing loss due to age, the hearing threshold of 5 week old mice with and without diabetes were measured. In order to measure the effect of diabetes on hearing recovery, 5 week old mice with and without diabetes were exposed to broad band white noise 110 dB for 3 hours. The hearing threshold of these mice were measured before exposure and 1, 3, and 5 days and 2, 3, and 4 weeks following. There was no significant difference between the hearing thresholds of diabetic and non-diabetic mice in hearing recovery. However, there was a significant difference between the hearing thresholds in diabetic and non-diabetic mice due to aging.

J Audiol Otol. 2015 Dec; 19(3):138-143.

Further studies should be conducted to measure even longer-term effects of diabetes on hearing. The applicability of the study to humans could be studied as well as possible methods of prevention. I think this study is important for pharmacists to know because it adds another counseling point for when we talk to patients with diabetes. Additionally, we can be aware of the population we are serving by understanding that they may not be able to hear us as well as someone their age without diabetes.

Increasing Medical Treatment for Hearing Loss

Hearing loss has become an increasingly prominent issue in the elderly population. Because current generations will live longer lives than previous generations, the problems associated with aging, such as heading loss, will and has become a larger problem in our society. There is a huge issue in regards to treatment and availability of treatment to these patients. Medicare does not cover the cost of hearing aids, which can be very expensive and is most likely the reason why only one in five people suffering from hearing loss use hearing aids. Additionally, there is a problem in the assessment of hearing. In most cases, patients must complain about their hearing in order for a hearing test to be implemented at a doctor’s appointment being that hearing is not usually included in primary care evaluations. The medical lapse in the field of hearing loss can be associated with the idea that hearing loss is natural in the aging process and it is not due to a biological error, therefore does not need medical intervention. However, the effects of medical treatment in hearing loss have increased the productivity, independence and quality of life for these elderly patients.

As a student pharmacist aspiring to enter the medical field, it is an obligation to help patient’s in need in order to increase their quality of life. An emphasis should be placed on improving the treatment availability for hearing loss in all ages, with a concentration on the elderly population. Over 40% of individuals over 60 suffer from hearing loss and the number doubles by the time the population reaches eighty years old with 80% having hearing impairments. Identifying the problem and monitoring yearly can increase the number of patients who receive treatment and possibly prevent the delay in availability of the hearing treatment. This article emphasizes the need for an improvement in areas such as research, treatment availability and insurance coverage.

Cassel, C, Penhoet E, et al. Policy Solutions for Better Hearing. JAMA Intern Med. 2016. Published online January 21, 2016.

JAMA. Published online January 21, 2016