Ototoxicity Research Articles

Studying ototoxicity in chicken.

Studying ototoxicity in chicken.

Vancomycin Induced Thrombocytopenia Complicating Permanent Pacemaker Placement: A Case Report

Introduction: Vancomycin is widely used in patients with methicillin resistant staphylococcus aureus (MRSA) infections or with other infections unresponsive to other antibiotics. Vancomycin-related adverse effects, including nephrotoxicity, ototoxicity, red-man syndrome, and neutropenia have been reported. Vancomycin induced thrombocytopenia is a rare complication of vancomycin that many physicians are unaware of. When an acute decline in platelet count or bleeding occur in patients on vancomycin, vancomycin- induced thrombocytopenia should be considered. Case: We present a case of acute severe thrombocytopenia that occurred within 12 hours after vancomycin infusion in a patient that received permanent pacemaker placement. Vancomycin was discontinued and patient’s platelets returned to baseline five days after vancomycin was discontinued. Conclusion: This case report highlights the importance of physicians being aware of vancomycin induced thrombocytopenia, a rare but reversible complication of vancomycin, which if diagnosed early will lead to early discontinuation of vancomycin, early resolution of thrombocytopenia and reduced hospital stay.

Drugs inducing hearing loss, tinnitus, dizziness and vertigo: an updated guide.

The awareness of audio-vestibular side effects of drugs, such as hearing loss, tinnitus, dizziness and vertigo, has widely increased in the recent years. The present guide represents an update of the previous documents published by the authors in 2005 and 2011 on drug-induced ototoxicity and vestibulotoxicity. The authors performed a comprehensive analysis of audio-vestibular side effects of commercially available drugs based on the British National Formulary, a pharmaceutical reference book that contains a wide range of useful information and advice on prescription and pharmacology. Commercially available drugs and their active principles have been classified based on their audio-vestibular side effects, as reported by the pharmaceutical companies and/or health agencies. Drugs have been categorized based on the field of application, the therapeutic indication and the pharmacological properties. General practitioners, otolaryngology, neurology and audiology specialists should be aware of possible audio-vestibular side effects of drugs, such as hearing loss, tinnitus, dizziness and vertigo. The present guide represents a practical tool to rapidly identify potential audio-vestibular side effects of drugs as reported by the pharmaceutical companies and/or health agencies.

Tick-induced vestibular ototoxicity and facial nerve paralysis successfully treated with intratympanic steroid injections

Tick infestation causing facial nerve palsy has been reported especially in Southeast Asian (this) region of the world. However, there has not been a report of tick infestation causing vestibular ototoxicity. A detailed otology history and careful otoscopic examination is paramount when an abnormal presentation is seen. Timely and appropriate treatment will mitigate long-term sequelae of toxicity. We report a case of a patient presenting with dizziness, reduced hearing, and unilateral facial paralysis secondary to tick infestation. We outline the successful management of this condition.

Investigating the effect of Hypericum Perforatum L. on hearing in rats: An experimental study

Objectives: Hypericum perforatum L. (HP) is among the oldest used and most comprehensively studied medicinal herbs. Anti-inflammatory activities of different Hypericum extracts on external auditory canal and also in the prevention of tympanic membrane perforation and myringosclerosis were investigated experimentally in the animal model. This study was to investigate whether or not intratympanic injection of H. perforatum L. in the middle ear of the rats causes ototoxicity, via auditory brainstem response (ABR). Materials and Methods: Rats were assigned to three groups as Group C, S, and D. Excessive external auditory canal edema developed in the rats in Group D as of the 5th day and Group D was excluded from the study by considering that ABR records could be affected. Results: A statistically significant difference was observed mean latency values of the wave V and III at the baseline and on the 7th day in Group S (P < 0.05). A significant shortening was calculated in the interpeak mean latency values of the waves III–V at the baseline and on the 7th day in Group S (P < 0.05). A statistically significant difference was observed between the baseline III–V wave interpeak mean latency values in the between-group evaluation on the 7th day (P < 0.05). A statistically significant difference was detected in the mean values of the wave V/Va amplitude ratios at the baseline and on the 7th day in Group S (P < 0.05).In the between-group evaluation, a statistically significant difference was found in the mean values of the wave V/Va amplitude ratios on the 7th day (P < 0.05). Conclusion: The results of the study conducted in accordance with the hypothesis point out that the intratympanic injection of H. perforatum L. may have an ototoxic effect.

Alarming levels of ototoxicity among multidrug resistant tuberculosis patients on intensive phase of treatment at specialist treatment centers in South Western, Nigeria

Management of multi drug resistant tuberculosis (MDR-TB) patients remains a challenge in the control of tuberculosis worldwide. MDR-TB patients require long term treatment with drugs that cause various adverse effects especially ototoxicity associated with aminoglycoside. Current treatment guidelines still include aminoglycosides use especially in developing countries. However, there is dearth of information regarding ototoxic effects of MDR-TB treatment in Nigeria. This study explored the prevalence of ototoxicity and associated factors among MDR-TB patients during the intensive phase of treatment. A retrospective review of records of 383 MDR-TB patients admitted at two specialist treatment centers in South West Nigeria from 2012-2017 was conducted. Using a structured proforma, socio demographic characteristics and clinical history were extracted. Ototoxicity was assessed as any abnormality reported from a pure tone audiometry. Discrete data were summarized with frequencies, proportions while bivariate analysis was done using chi square test to identify associated factors. Multivariate analysis was performed to identify independent predictors of ototoxic effects. All statistical significance was set at 5%. Out of the 383 records extracted, only 143(37.3%) had audiometry performed. Of these 143 MDR-TB patients, mean age was 36.2 ± 11.3 years and prevalence of any ototoxic effect was 72.7 %. This was higher in older age groups, females and those underweight. (p>0.05) Patients who did not sputum convert at the end of treatment and HIV co infected had higher proportions with ototoxic effects (p < 0.05). However, on multivariate analysis only age remained a significant independent predictor of ototoxic effect (AOR: 8.7; 95% CI: 1.4-52.2). Adverse effects are main deterrents to compliance and completion of long term treatment regimen. High rates of ototoxic effects as seen in this study could affect successful management of MDR-TB patients. Auditory monitoring and rehabilitation should be recommended for MDR-TB patients even after completion of the intensive phase of treatment. Key words: Aminoglycoside ototoxicity, drug resistant tuberculosis, Nigeria.

Reduction in Ototoxicity Using IMRT for Patients with Medulloblastoma/PNET

Reduction in Ototoxicity Using IMRT for Patients with Medulloblastoma/PNET

Prevention of treatment-induced ototoxicity: An update for clinicians

Prevention of treatment-induced ototoxicity: An update for clinicians

Hearing loss in infant with congenital cytomegalovirus infection

Hearing loss is one of the sequels that often happened as a result of congenital cytomegalovirus (CMV) infection. Difficulties in diagnosing congenital CMV infection cause late detection of hearing loss which affects the patient's management and prognosis. We present three cases of hearing loss in infants with congenital CMV infection with other risk factors such as hyperbilirubinemia, low birth weight, premature birth, and ototoxic drug usage. The results of hearing assessment, imaging findings, and antiviral treatments are discussed. Hearing assessments in patient with congenital CMV infection should be checked routinely because hearing loss in this disease can be progressive and fluctuating.

Ototoxicity from the aminoglycoside-heparin/ citrate locks applied for the prevention of hemodialysis catheter-related infections.

Ototoxicity from the aminoglycoside-heparin/ citrate locks applied for the prevention of hemodialysis catheter-related infections.

Identification of risk factors for hearing impairment in newborns: a hospital based study.

Aim To identify risk factors for hearing impairment presented in neonates born in Cantonal Hospital Zenica (CHZ) and to estimate their influence on outcome of hearing tests in Newborn Hearing Screening (NHS). Methods Retrospective-prospective study was done at the Department of Gynaecology and Maternity. The NHS was performed with transitory evoked otoacoustic emissions (TEOAE) during a six-month period using "Titan" device (Interacoustics, Denmark). The questionnaire was written for the purpose of getting more structured basic information about every newborn and to identify risk factors for hearing impairment. Chi-square test was used to investigate the difference between experimental and control group refer incidence. Results A total of 1217 newborns was screened for hearing impairment of which 259 (21.28%) with one or more known risk factors for hearing impairment. The following risk factors for hearing impairment were identified during the study period: family history of permanent childhood hearing impairment in 42 (3.45%) newborns, prematurity in 39 (3.21%), low APGAR scores in 29 (2.40%), asphyxia in 31 (2.55%), hyperbilirubinemia in 41 (3.37%), admission of ototoxic medication (aminoglycosides) after birth in 155 (12.74%). Conclusion There were many serious risk factors for hearing loss identified in this study. Identification of risk factors for hearing impairment in neonates is necessary because a follow up of the children with risk factors is very important.

Research progress of pathogenic factors in children with hearing impairment

Hearing impairment is one of the most common disabilities in children, which seriously affects the quality of lives as well as physical and mental development of children.Hearing impairment is high risk and harmful, which brings heavy burden to the families and society.We could take preventive measures to reduce the incidence of this disease after exploring the pathogenic factors of hearing impairment.Viral infection and nicotine may directly or indirectly damage the vestibulocochlear organ and cause gene mutation.Noise and inflammation may cause direct mechanical damage and induce auditory cell apoptosis, while ototoxicity drugs may mediate a temporary weakening or delayed auditory impairment by inner ear hair cell apoptosis, neural degeneration and repair dysfunction.There are lots of ways to cause hearing loss and the pathogenic factors of hearing loss are complex and varied.This paper reviews the aspects of fetal, neonatal, genetic, drug and other factors associated with hearing impairment. Key words: Hearing impairment; Pathogenic factors

Vitiligo and its association with hypoacusis: A case control study

Vitiligo is a pigmentary disorder with absence of functional melanocytes in the affected area. Melanocytes originate from neural crest and migrate to rest of the body in a cephalo-caudal manner in the embryonic life. Apart from epidermis and hair bulb in skin, they are also present in leptomeninges, inner ear, retina and uveal tract. In the inner ear melanocytes are present in endolymphatic sac, hair cells, vestibular organ and striavascularis. Vitiligo is not just skin deep and is also responsible for subclinical hypoacusis in majority of patients. Patients suffering from vitiligo affecting the head and neck region at the time of origin are more prone to the auditory dysfunction. Leucotrichia is another association with asymptomatic sensori-neural hypoacusis. This is due to the loss of melanocytes which have a protective role in inner ear. TEOAE and Pure tone audiometry can be used effectively for screening patients and these patients should be informed regarding the noise exposure and ototoxic drugs.

Retrospective review of oscillopsia: etiologies and clinical characteristics

Background: Oscillopsia can result from dysfunction involving the vestibuloocular reflex (VOR). Few studies have detailed the full spectrum of clinical characteristics and laboratory findings of this disabling condition. Objectives: To review causes and clinical characteristics of oscillopsia. Methods: Retrospective review of clinical records of a series of patients with oscillopsia from the University Health Network Multidisciplinary Neurotology Clinic. Results: Review of 109 patients with oscillopsia showed near equal sex distribution and a mean age of 54.9 years (standard deviation 15.7). The most common peripheral vestibular causes were ototoxicity (19.3%) and Meniere’s disease (10.1%). The most common central cause involved cerebellar degeneration (7.3%). Only 43.1% complained of vertigo at any time. Head impulse testing demonstrated bilateral refixation saccades in 70% of patients, while over 95% had a loss of dynamic visual acuity ?5 lines on LogMAR chart testing. Some 38.8% of patients demonstrated normal caloric responses, whereas only 26.5% exhibited evidence of a bilateral caloric loss. Over 50% of patients maintained otolithic function as demonstrated by cervical vestibular evoked myogenic potential testing. Most patients demonstrated low VOR gains bilaterally on magnetic scleral search coil testing. Conclusions: A wide spectrum of clinical characteristics was identified in patients with oscillopsia. It is important for the physician to perform a thorough history, physical examination (including head impulse and dynamic visual acuity), and laboratory investigations. Keywords: Bilateral vestibular loss, magnetic scleral search coil, oscillopsia, vestibuloocular reflex

Analysis of adverse drug reactions in multidrug-resistant pulmonary tuberculosis patients

Objective To analyze the adverse drug reactions (ADR) during the standardized treatment of multidrug-resistant pulmonary tuberculosis (MDR-PTB), and to evaluate its impact on treatment outcomes. Methods A retrospective study was carried out on 305 MDR-PTB patients. Medical records of clinical treatment and laboratory examinations were collected, and the ADR data were analyzed.Chi-square test or Fisher exact test was used for discontinuous variables, and t test or non-parametric test was used for continuous variables. Results Among 305 MDR-PTB patients , 282 (92.5%) had at least one ADR. The major ADR were gastrointestinal reaction (46.9%), thyroid dysfunction (41.3%), hypokalemia (34.1%), renal injury (29.8%), hematological system impairment (21.6%), hepatotoxicity (19.0%), arthralgia or courbature (11.1%), and ototoxicity and vestibular dysfunction (8.5%). Sex, age, native place, the history of using second-line TB drugs or the history of diabetes mellitus had no significant effect on the incidence of ADR (all P>0.05). As per the Naranjo causality assessment of ADR, 34 patients had definite, 236 had probable, 12 had possible and 0 had doubtful causal relations. Among the 282 cases with ADR, 175 (62.1%) patients continued the original treatment regimen, 89 (31.6%) patients changed or stopped ADR-related drugs, only 18 (6.4%) cases stopped MDR-PTB treatment. The episodes of ADR had no significant effect on the treatment outcomes (P>0.05). Conclusions Although ADR are common in MDR-PTB patients during the treatment course, most of the ADR can be managed. Through timely monitoring and appropriate treatment of ADR, most of the patients could continue MDR-PTB treatment. Key words: Tuberculosis, pulmonary; Tuberculosis, multidrug-resistant; Therapy; Adverse drug reactions

Otitis externa beim Hund

Otitis externa (OE) is defined as an inflammation of the external ear canal and its prevalence is reported to be 5-13%. The pathogenesis of OE is often multifactorial. The PSPP-System identifies and differentiates primary and secondary causes and predisposing and perpetuating factors contributing to OE and helps the clinician to establish a therapeutic plan. For a successful therapy of OE to identify and treat all contributing causes and factors in each individual case. Frequent causes of canine OE are hypersensitivities to food and environmental allergens, foreign bodies and hypothyroidism. To achieve good owner compliance the clinician needs good communication skills. A clinical and otoscopic examination and ear cytology are needed to make the diagnosis of OE. The usefulness of bacterial cultures and susceptibility testing in cases of OE is currently under debate. The gold standard for drug application in OE is topical as higher drug concentrations are achieved in the ear compared to systemic treatment. A lot of commercial ear products and ear cleaners are available. The clinician should be aware of their ingredients, their mode of action and possible ototoxic effects. Short term therapy with systemic glucocorticoids can be useful in cases of stenotic ear canals. Surgery might be the only successful treatment in end-stage otitis externa.

Effect of coenzyme A on outer hair cells in cisplatin ototoxicity: functional and ultrastructural study.

The aim of this study was to use functional and morphological analyses to evaluate the protective effect of coenzyme A (CoA) in cisplatin-induced toxicity in outer hair cells (OHC). Three groups of 8 guinea pigs were used: control (group I), cisplatin-treated (group II) and cisplatin + CoA-treated (group III). In groups II and III, a single ototoxic dose of cisplatin (10 mg/kg) was injected intraperitoneally. Group III was co-treated with CoA (900 μg/kg per day for 7 consecutive days). Electrocochleography (ECoG) recordings were made before and after the 7-day treatment period in all groups. After ECoG on day 7, all animals were anesthetized and the cochleae were removed and fixed for ultrastructural analysis. Cell damage in OHC was observed with transmission electron microscopy. Cisplatin induced a significant increase in auditory thresholds (p<0.001) compared to group I (control). In contrast, group III (cisplatin + CoA) had significantly reduced thresholds (p<0.001) compared to the group treated with cisplatin alone (group II).We found no significant differences between the control group and animals co-treated with cisplatin and CoA. The electron microscopy findings in OHC were consistent with these results. Ultrastructural analysis of OHC in group II showed morphological indications of necrosis, i.e. cytoplasmic swelling and vacuolation, and mitochondrial swelling. In group III the cell morphology of OHC was preserved, with ultrastructural characteristics similar to the control group. In conclusion, co-treatment with cisplatin with CoA inhibited antineoplastic-induced cytotoxicity in OHC in a guinea pig model.

Aminoglycoside-induced hearing deficits - a review of cochlear ototoxicity : research

This article aims to inform the reader about current knowledge of the effects of aminoglycosides on hearing. The hearing loss caused by aminoglycosides is permanent and can negatively affect the individualâ??s quality of life. Although treatment with aminoglycosides cannot be avoided in some instances, timely intervention can minimise the impact of the hearing loss on the individual's everyday life. The discussion includes the incidence of aminoglycoside-induced hearing loss and predisposing factors. In addition, monitoring and management of cochlear ototoxicity is described.

Efficacy evaluation of teicoplanin and vancomycin in the treatment of methicillin-resistant Staphylococcus au-reus（MRSA） pneumonia

Objective To compare the safety and effectiveness of teicoplanin and vancomycin in treatment of MRSA pneumonia .Methods 68 cases of patients with MRSA pneumonia were divided into two groups by random numbers：the observation group of 34 cases with teicoplanin for treatment;the control group of 34 patients with the van-comycin for treatment .The clinical efficacy , bacteriological efficacy and adverse reactions for two groups were com-pared.Results the total efficiency for observation group and control group were 82.35%and 76.47%,respectively, and the total bacterial clearance rate were 91.18%and 85.29%,respectively.The clinical efficacy and bacteriologi-cal efficacy in observation group were slightly higher than that in control group （P>0.05）;observation group had ad-verse events of erythema ,rash and diarrhea for 1 patients each;the control group had adverse events of renal toxicity in four cases and ototoxicity ,phlebitis,diarrhea in 1 case,the total incidence of adverse reactions in observation group was slightly lower than that in the control group （P>0.05）.Conclusion Teicoplanin in treatment of MRSA pneumo-nia has good efficacy with lighter kidney damage ,which is similar to the vancomycin ,and it is worthy clinical promo-tion and application . Key words: Methicillin-resistant staphylococcus aureus; Teicoplanin; Vancomycin

Debridement combined with local anti-TB drugs delivery for thoracic and lumbar spine tuberculosis

Objective To investigate a therapeutic method which could provide sustained-release delivery and local longlasting anti-TB treatment after debridement of thoracic and lumbar spine tuberculosis.Methods Data of 18 patients (including 2 revised cases),who were diagnosed of thoracic and lumbar tuberculosis and required surgery treatment from October 2008 to January 2011 were retrospectively analyzed.There were 12 males and 6 females,with an average age of 48.7± 13.3 years (range,22 to 67 years).Affected spinal segments in these patients spanned from T8 to S1.fourteen patients were treated with posterior surgical procedure alone while the other 4 were treated with one-stage combined anterior-posterior surgery.Combined with autogenous bone,OSTEOSET RBK drug carrier-type artificial bone mixed with isoniazid and streptomycin was used after debridement.Chlinical parameters including clinical symptoms,laboratory results,and imaging data were evaluated during follow-up.Results Incisions of all patients achieved primary healing.The duration of patient follow-up ranged from 29 to 56 months (average,39.5months).No liver and kidney function abnormalities,ototoxicity,or local nerve irritations were found perioperatively.Improvements in clinical symptoms were observed in all patients.One patient with L2a tuberculosis recurred 18 months after the initial surgery.At 6-month follow-up,intervertebral body fusion was achieved without complications of internal fixation or significant angle loss of kyphosis correction.Conclusion OSTEOSET RBK dmg carrier-type artificial bone mixed with isoniazid,streptomycin for treatment of thoracic and lumbar spine tuberculosis is a safe and effective way to control local infection and recurrence.Combined with autologous bone could contribute to bone fusion. Key words: Thoracic vertebrae; Lumbar vertebrae; Tuberculosis, Spinal; Bone substitutes