Doctor Educationis / Ototoxic induced hearing loss is a common adverse event related to aminoglycosides used in Multi
Drug Resistant -Tuberculosis treatment. Exposure to ototoxic drugs damages the structures of the
inner ear. Symptomatic hearing loss presents as tinnitus, decreased hearing, a blocked sensation,
difficulty understanding speech, and perception of fluctuating hearing, dizziness and
hyperacusis/recruitment. The World Health Organization (1995) indicated that most cases of ototoxic
hearing loss globally could be attributed to treatment with aminoglycosides.
The aim of the study was to determine the proportion of DR-TB patients initiated on treatment at
three decentralized sites during a defined period (1st October to 31st December 2015) who
developed ototoxic induced hearing loss and the corresponding risk factors, whilst receiving
audiological monitoring with an extended high frequency audiometer (KUDUwave).
A retrospective cross-sectional study was conducted. Cumulatively across the three decentralized
sites, 69 patient records were reviewed that met the inclusion criteria of the study. The mean age of
the patients was 36.1, with a standard deviation (SD) of 10.7 years; more than half (37) were female.
Ototoxicity , a threshold shift, placing patients at risk of developing a hearing loss was detected in
56.5% (n=39)of patients and not detected in 30.4%(n=21).The remaining 13,1% (n=9)is missing
data. As a result, the regimen was adjusted in 36.2% of patients. .
From the 53 patients who were tested for hearing loss post completion of the injectable phase of
treatment, 22.6% (n=12) had normal hearing, 17.0 % (n=9) had unilateral hearing loss, and 60.4%
(n=32) had bilateral hearing loss. Therefore, a total of 41 patients had a degree of hearing loss:
over 30% (n=22)had mild to moderate hearing loss, and only about 15% (n=11)had severe to
profound hearing loss. Analysis of risk factors showed that having ototoxicity detected and not
adjusting regimen significantly increases the risk of patients developing a hearing loss.
The key findings of the study have shown that a significant proportion of DR-TB patients receiving
an aminoglycoside based regimen are at risk of developing ototoxic induced hearing loss, despite
receiving audiological monitoring with an extended high frequency audiometer that allows for early
detection of ototoxicity (threshold shift).
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/6721 |
| Date | 10 1900 |
| Creators | Rudolph-Claasen, Zerilda |
| Contributors | Knight, Lucia |
| Publisher | University of the Western Cape |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Rights | University of the Western Cape |
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