Ototoxicity of topical otomicrobial agents

Effects of preservatives on the activities of salivary enzymes

OBJECTIVES

To investigate the effects of common preservatives used in oral health care products on the enzymatic activities of lysozyme, peroxidase, and α-amylase in-solution and on-hydroxyapatite surface phases.

DESIGN

The preservatives used in this study were sodium benzoate, methylparaben, propylparaben, and benzalkonium chloride. Hen egg-white lysozyme, bovine lactoperoxidase, and α-amylase from Bacillus sp. served as sources of purified enzymes. Human unstimulated whole saliva was used as a source of salivary enzymes. Hydroxyapatite beads were used as the surface phase. The preservatives were incubated with purified enzymes or saliva samples in-solution or on-hydroxyapatite surface phases, respectively. Enzymatic activities of lysozyme, peroxidase, and α-amylase were measured by hydrolysis of fluorescein-labelled Micrococcus lysodeikticus, oxidation of fluorogenic 2',7'-dichlorofluorescin, and hydrolysis of fluorogenic starch, respectively.

RESULTS

The effects of the preservatives on the enzymatic activities of lysozyme and peroxidase were more distinct in the saliva samples than purified substances, and in the in-solution phase than on-hydroxyapatite surface phase, and the opposite was true for α-amylase. The most significant result was apparent decrease in peroxidase activities caused by the parabens in the in-solution phase (P<0.05). Sodium benzoate and parabens inhibited lysozyme activity in the in-solution phase, but differently for the purified and salivary lysozymes. Parabens and benzalkonium chloride inhibited the enzymatic activity of α-amylase from Bacillus sp., not saliva samples, only on-hydroxyapatite surface (P<0.05).

CONCLUSIONS

Each preservative affected the enzymatic activities of lysozyme, peroxidase, and α-amylase differently. Based on the effects on salivary enzymes, sodium benzoate or benzalkonium chloride was recommended as preservatives rather than parabens.

Chronic suppurative otitis media

Chronic suppurative otitis media (CSOM) is a leading global cause of potentially preventable hearing loss in children and adults, associated with socioeconomic deprivation. There is an absence of consensus on the definition of CSOM, which complicates efforts for prevention, treatment, and monitoring. CSOM occurs when perforation of the tympanic membrane is associated with severe or persistent inflammation in the middle ear, leading to hearing loss and recurrent or persistent ear discharge (otorrhoea). Cholesteatoma, caused by the inward growth of the squamous epithelium of the tympanic membrane into the middle ear, can also occur. The optimal treatment of discharge in CSOM is topical antibiotics. In resource-limited settings where topical antibiotics might not be available, topical antiseptics are an alternative. For persistent disease, surgery to repair the tympanic membrane or remove cholesteatoma might offer long-term resolution of otorrhoea and potential improvement to hearing. Recent developments in self-fitted air-conduction and bone-conduction hearing aids offer promise as new options for rehabilitation.

Can A Sudden Sensorineural Hearing Loss Occur Due to Miliary Tuberculosis?

Miliary tuberculosis is a severe form of tuberculosis resulting from dissemination of Mycobacterium tuberculosis bacilli. Since symptoms appearing in patients due to miliary TB are diverse and atypical, depending on the site of invasion, early diagnosis and treatment are important. A paradoxical response of tuberculosis is a rare phenomenon and it can be a clinical difficulty to treatment especially when involving the central nervous system. We present a case report with a review of related literature about the patient who developed sudden hearing loss due to tuberculosis infection in vestibulocochlear area.

Comparison of local and systemic ciprofloxacin ototoxicity in the treatment of chronic media otitis

Introduction:

Chronic media otitis is a common cause of reference to ear, nose and throat clinics and the treatment is one of the health problems among ENT specialists. Ciprofloxacin drop that is of fluoroquinolone drug class due to good treatment effect is now widely used in the treatment of chronic media otitis. Due to the widespread use, it seems proper research on the human population has not been taken to ensure its non-toxicity in the inner ear, therefore comparison of local ciprofloxacin ototoxicity with systemic in chronic media otitis is investigated in this study.

Materials and Methods:

This study was conducted as a randomized clinical trial. Prospective methods were considered and the number of samples in the study group was 40 patients that were treated with ciprofloxacin drops. And in the control group 32 patients with chronic media otitis who were treated with ciprofloxacin tablets. The collected data was analyzed using SPSS software.

Results:

Statistical indicators of different frequencies in air conduction (AC) in both groups showed, there was significant improvement in hearing thresholds at frequencies of 250, 8000, 1000 in air conduction for the group receiving drops compared to the group receiving tablet. Based on statistical indicators in different frequencies of bone conduction in the two treated groups, there was significant difference in the two groups receiving tablets and drops only at a frequency of 4000Hz that drop impact improves hearing threshold and in contrast in the group receiving tablet hearing loss was seen in the frequency of 4000.

Discussion:

Topical ciprofloxacin is a safe and uncomplicated ototoxic drug that is an effective antibiotic used in the treatment of refractory chronic otitis those dregs such as pseudomonas aerogenusa and staphylococci resistant to methicillin are responsible for it, which in the usual doses has not harmful effects on hearing hairy cells.

Steroids in aminoglycoside-containing ear drops: do they reduce cochlear toxicity?

OBJECTIVES/HYPOTHESIS

To determine whether betamethasone (BM) reduces the cochlear toxicity of otic gentamicin (GM) if given together.

STUDY DESIGN

Controlled animal study.

METHODS

Thirty-four mice were assigned at random to receive intratympanic injections of either 0.1 % BM (11 mice), 0.3% GM (13 mice), or a combination of both (GM/BM) with benzalkonium chloride (10 mice) in the left ear (treated) and saline on the right (untreated). Six injections were given on alternate days. Auditory brainstem response thresholds were assessed at 1 month, 2 months, and >2 months.

RESULTS

There was a significantly greater degree of hearing loss in the BM-treated ears compared to the untreated ears (6.48 dB hearing loss, P = .007) and in the GM-treated ears compared to untreated ears (6.59 dB hearing loss, P = .010,). However, otic GM/BM and benzalkonium chloride did not cause significant additional hearing loss compared with the untreated ears (3.56 dB hearing loss, P = .242).

CONCLUSIONS

Our data suggest that hearing loss caused by GM otic drops may be reduced by the inclusion of BM and benzalkonium chloride. Our finding that BM alone was associated with hearing loss suggests that the benzalkonium chloride may be the protective agent in combination otic drops.

Differences in bacteriologic treatment failures in acute otitis externa between ciprofloxacin/dexamethasone and neomycin/polymyxin B/hydrocortisone: results of a combined analysis

OBJECTIVE

To compare treatment failure rates for the two major acute otitis externa (AOE) pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, by topical therapy with ciprofloxacin 0.3%/dexamethasone 0.1% (CDex) or neomycin 0.35%/polymyxin B 10,000 IU/mL/hydrocortisone 1% (Cort) based on clinical and microbiological failure in patients positive for these pathogens at baseline.

RESEARCH DESIGN AND METHODS

A combined analysis was conducted from two similar, but non-identical clinical trials involving CDex vs. Cort. Outcomes of the combined efficacy analysis were treatment failure rates and antibiotic susceptibility values for P. aeruginosa and S. aureus. The raw data for the treatment failure rates from the two studies were combined to calculate the overall treatment failure rates of each treatment group. Chi-square tests of independence were conducted to assess differences in treatment failure rates between treatment groups.

RESULTS

Of the 789 patients with culture-positive ears prior to the initiation of therapy, 61.0% (n = 481) were positive for P. aeruginosa and 8.9% (n = 70) were positive for S. aureus. While treatment failure rates for S. aureus were similar for the two therapies, CDex had a significantly lower treatment failure rate than Cort (5.1 vs. 13.0%; p = 0.0044) for P. aeruginosa. All of the persisting P. aeruginosa and S. aureus isolates were susceptible to fluoroquinolones and neomycin/polymyxin B.

LIMITATIONS

The analysis strength is dependent on pooled data from similar studies.

CONCLUSIONS

Ototopical ciprofloxacin 0.3%/dexamethasone 0.1% more effectively eradicates P. aeruginosa compared to Cort. Eradication of S. aureus by either drug was similar. These results favor CDex as a better first-line choice in the treatment of AOE compared to Cort.

Ototoxicity of Ototopical Drops—An Update

Various topical preparations are widely used for treating external otitis, acute otitis media with perforation, post-tympanostomy tube otorrhea, and chronic suppurative otitis media. Solutions and suspensions that enter the middle ear through a perforated tympanic membrane can reach the inner ear by crossing through the round window membrane. The safety of various components of otic solutions used in this way, particularly aminoglycosides, corticosteroids, solvents, and preservatives, has been questioned in light of their ototoxic potential. The authors' objective is to review the literature discussing the safety of commonly used classes of otic preparations in settings in which the constituents can access the middle and inner ear in high concentrations and discuss their clinical experience with ototoxicity and experience with medical-legal issues.

Development of novel LL-37 derived antimicrobial peptides with LPS and LTA neutralizing and antimicrobial activities for therapeutic application

New peptides for lipopolysaccharide (LPS) and lipoteichoic acid (LTA) neutralization in upper respiratory tract infections were developed and evaluated in terms of efficacy and safety for application in humans. Based on the sequence of the human antimicrobial peptide LL-37 we developed and investigated length variants, substitution analogues and modifications to stabilize the peptides to prevent enzymatic degradation and to improve efficacy. The most promising peptide appears P60.4, a 24 amino acid peptide with similar efficacy as LL-37 in terms of LPS and LTA neutralization and lower pro-inflammatory activity. In addition, the acetylated and amidated version of this peptide shows no toxicity and displays higher or equal antimicrobial activity compared to LL-37.

External otitis caused by infection with Pseudomonas aeruginosa or Candida albicans cured by use of a topical group III steroid, without any antibiotics

CONCLUSIONS

Irrespective of the microbial agent, group III steroid solution cured external otitis efficiently in a rat model. The addition of antibiotic components to steroid solutions for the treatment of external otitis is of questionable validity.

OBJECTIVE

External otitis, caused by infection with either Pseudomonas aeruginosa or Candida albicans, was established in a rat model and the treatment efficacy of a group III steroid solution was studied.

MATERIAL AND METHODS

Three treatments were studied: (i) a group III steroid solution; (ii) a group I steroid combined with two antibiotic components; and (iii) a saline solution. A scoring scale was used to evaluate the characteristics of the ear canal skin. Bacteriological and fungal samples were collected for culturing and ear canal skin biopsies were taken for structural analyses.

RESULTS

It was possible to cause P. aeruginosa and C. albicans infections in an animal model. In the P. aeruginosa-infected animals, only the group III steroid treatment cured all the animals. In the C. albicans-infected animals, group III steroid treatment resolved external otitis faster than the other treatment modalities.

Management of the draining ear in children

There are a variety of causes of otorrhea in children. The most important factor in reaching the proper diagnosis and providing relief of the problem is aural toilet. Once adequate debridement has been performed, the diagnosis is usually clearer, and treatment with ototopicals is significantly more effective. Most cases of otorrhea are due to infection or granulation tissue and can be managed initially with appropriately selected ototopical medication, thereby avoiding the risks and side effects of systemic therapy and the need for referral to a specialist. However, otorrhea in children that is refractory to medical therapy may be due to retained tympanostomy tubes or insidious pathology such as cholesteatoma or malignancy. In such cases, prompt referral to the otolaryngologist can facilitate accurate diagnosis and successful management.

Conservation of low-frequency hearing in cochlear implantation

OBJECTIVES

As results with cochlear implants have continued to improve, patients with some remaining cochlear function have become eligible for cochlear implantation. Thus, preservation of acoustic hearing after implantation has gained importance. Hearing preservation can be considered a benchmark for atraumatic implantation preventing neural degeneration from loss of residual hair cells or subsequent to local trauma. In this prospective study, the possibility of preserving low-frequency hearing in cochlear implantation using a modified surgical technique has been explored.

MATERIAL AND METHODS

In a prospective study design, 14 subjects with considerable low-frequency hearing of 20-60 dB in the frequency range 125-500 Hz but with unsatisfactory speech understanding with hearing aids of < 35% monosyllabic word understanding were implanted with a MED-EL COMBI-40+ cochlear implant. The insertion depth was intentionally limited to 19-24 mm to prevent damage to low-frequency regions of the cochlea. Pre- and postoperative pure-tone thresholds were measured.

RESULTS

Hearing was conserved within 0-10 dB in 9/14 subjects and within 11-20 dB in 3/14; in 2/14 subjects hearing was completely lost in the implanted ear. Thus hearing could at least partially be conserved in 12/14 subjects (86%). Median threshold values decreased by 10, 15, 17.5 and 5 dB at 125, 250, 500 and 1000 Hz, respectively. Even high levels of hearing, e.g. 30 dB at 500 Hz, could be maintained after implantation in some subjects.

CONCLUSIONS

This study reports successful conservation of hearing after cochlear implantation using a modified surgical technique. Even high levels of hearing could be maintained, showing that implantation of an intracochlear electrode can be performed atraumatically with preservation of functional structures.

Effectiveness of ototopical antibiotics for chronic suppurative otitis media in Aboriginal children: a community-based, multicentre, double-blind randomised controlled trial

OBJECTIVES

To compare the effectiveness of ototopical ciprofloxacin (0.3%; CIP) with framycetin (0.5%), gramicidin, dexamethasone (FGD) eardrops (5 drops twice daily for 9 days) together with povidone-iodine (0.5%) ear cleaning as treatments for chronic suppurative otitis media (CSOM) in Aboriginal children.

DESIGN AND PARTICIPANTS

Aboriginal community-controlled, community-based, multicentre, double-blind, randomised controlled trial in eight Aboriginal Community Controlled Health Services across northern Australia, involving 147 Aboriginal children with CSOM.

MAIN OUTCOME MEASURES

Resolution of otorrhoea (clinical cure), proportion of children with healed perforated tympanic membrane (TM) and improved hearing, 10-21 days after starting treatment.

RESULTS

111 children aged 1-14 years (CIP, 55; FGD, 56) completed treatment. CSOM cures occurred in 64% (CIP, 76.4%; FGD, 51.8%), with a significantly higher rate in the ciprofloxacin group (P = 0.009, absolute difference of 24.6% [95% CI, 15.8%-33.4%]). TM perforation size and the level of hearing impairment did not change. Pseudomonas aeruginosa was the most common bacterial pathogen (in 47.6%), while respiratory pathogens were rare (in 5.7%).

CONCLUSIONS

Twice-daily ear cleaning and topical ciprofloxacin is effective at community-level in achieving cure for CSOM. Healthcare providers to Aboriginal children with CSOM should be given special access to provide ototopical ciprofloxacin as first-line treatment.

Topical ofloxacin for chronic suppurative otitis media and acute exacerbation of chronic otitis media: optimum duration of treatment

OBJECTIVE

To assess the optimum duration of topical ofloxacin therapy for chronic otitis media and to compare the response between patients with chronic suppurative otitis media (CSOM) and acute exacerbation of chronic otitis media (AE).

STUDY DESIGN

Prospective observational study.

SETTING

Five university hospitals and 30 affiliated institutions.

PATIENTS

A total of 294 patients who presented to the participating institutions with CSOM were enrolled. Among them, 268 patients were evaluable for safety and 237 were evaluable for efficacy (64 with CSOM and 173 with AE .

INTERVENTION

Ofloxacin otic solution was administered for as long as 4 weeks.

MAIN OUTCOME MEASURES

Clinical and bacteriologic assessment was done weekly during the treatment period. The clinical response was assessed on the basis of the symptom scores.

RESULTS

There were no differences between CSOM and AE patients with respect to sex, age, and severity. The most common bacterial isolate from middle ear discharge was Staphylococcus aureus. The clinical response rates in patients with CSOM and AE were 39.1% and 61.3% after 2 weeks of treatment and 57.8% and 75.1% after 4 weeks, respectively, and the bacterial eradication rate was 91.0% at 2 weeks and 94.6% at 4 weeks. Detection of new fungal infection did not increase as the duration of therapy was prolonged. No serious adverse events were reported.

CONCLUSIONS

The duration of treatment was shorter and the clinical response was higher in AE patients than in CSOM patients. The standard topical ofloxacin regimen for chronic otitis media should consist of a 2-week course from the aspect of bacteriologic efficacy, although patients showing insufficient symptomatic improvement after 2 weeks may benefit from another 1 or 2 weeks of therapy. Administration of this drug for as long as 4 weeks can increase the clinical efficacy without causing safety problems.

Determination of ototoxicity of common otic drops using isolated cochlear outer hair cells

OBJECTIVES

Otic drops are commonly used not only for otitis externa, but also for otorrhea in the presence of tympanostomy tubes or tympanic membrane perforations. Many studies have demonstrated the ototoxicity of common otic preparations such as Cortisporin otic drops (Monarch Pharmaceuticals, Bristol, TN). The purpose of this study was to assess the relative ototoxicity of common otic preparations by direct exposure to isolated cochlear outer hair cells (OHCs).

METHODS

OHCs from adult chinchilla cochlea were exposed to standard bathing solution (control), acetic acid, Acetasol HC (Alpharma USPD Inc., Baltimore, MD), Gentacidin (CIBA Vision Ophthalmics, Atlanta, GA), and Tobradex (Alcon, Fort Worth, TX). The cells were observed using an inverted microscope, and the images were recorded in digital still-frame and video, and analyzed on the Image Pro-Plus 3.0 program (Media Cybernetics, Silver Spring, MD).

RESULTS AND CONCLUSIONS

As measured by time to cell death and change in morphology of OHCs, acetic acid with or without hydrocortisone was most toxic to OHCs. Cortisporin was more cytotoxic than gentamicin and Tobradex.

A comparison of cortisporin and ciprofloxacin otic drops as prophylaxis against post-tympanostomy otorrhea

Myringotomy and tube insertion, a common pediatric surgical procedure, is frequently complicated by purulent otorrhea. Many otolaryngologists routinely use topical antibiotics as prophylaxis against post-tympanostomy otorrhea. The aminoglycosides (neomycin sulfate, tobramycin and gentamicin) contained in commonly used topical antibiotics as well as components of the solutions have been shown to be ototoxic in animal studies. Although little reported evidence of ototoxicity in humans exists, sporadic reports of sensorineural hearing loss linked to topical antibiotic use do exist, and the potential for sensorineural hearing loss must be considered. The purpose of this study is to compare the rate of post-tympanostomy otorrhea in a double-blinded randomized trial using either topical Ciprofloxacin, with no reported ototoxicity, or Cortisporin as prophylaxis. One hundred patients (200 ears) between ages 7 months and 11 years with a diagnosis of recurrent otitis media or chronic otitis media undergoing tympanostomy tube insertion were randomized into two equal groups. Three drops of either drop A or B were placed into each ear at the time of tube insertion and then three times daily for 3 days. Patients were examined at 3 weeks and details of otorrhea were obtained. The rate of otorrhea was analyzed using chi-square. The overall rate of otorrhea was 39 ears (19.5%), 17 (17%) ears for the Cortisporin group and 22 (22%) for the Ciprofloxacin group. The difference in rate of otorrhea was not statistically significant (P=0.372, 95% confidence interval equals -6-16%). Our data suggest that topical Cortisporin offers no benefit over Ciprofloxacin for post-operative otorrhea prophylaxis. Therefore we recommend topical quinolone prophylaxis, which should eliminate concerns about ototoxicity, without sacrificing efficacy.

Safety of ofloxacin otic and other ototopical treatments in animal models and in humans

To assess the safety of topical agents in the middle ear, animal studies were reviewed. Compared with aminoglycoside-containing preparations, which caused significant loss of hair cells in the basal turn of the cochlea, ofloxacin caused no loss of hair cells, even at concentrations higher than used clinically. Moreover auditory brainstem testing revealed no change in auditory thresholds in the ofloxacin-treated animals, whereas neomycin-treated animals showed substantial threshold shifts. In human studies, use of topical ofloxacin 0.3% was not associated with any change in hearing. Topical ofloxacin has no demonstrable adverse effects on middle ear or cochlear function.

Effects of common topical otic preparations on the morphology of isolated cochlear outer hair cells

Otic drops are commonly used not only for otitis externa but also for otorrhea in the presence of tympanostomy tube or tympanic membrane perforation. Many studies have demonstrated the ototoxicity of common otic preparations such as Cortisporin otic drops. Recent studies have suggested the use of fluoroquinolone antibiotic drops as an alternative owing to their excellent antimicrobial coverage and no ototoxic effect. The purpose of this study was to assess the relative ototoxicity of four common otic preparations by direct exposure to isolated cochlear outer hair cells (OHCs). OHCs from adult chinchilla cochlea were exposed to standard bathing solution (control), Cortisporin, Cipro HC, Ciloxan, and Floxin. The cells were observed using an inverted microscope, and the images recorded in digital still-frame and video, and analyzed on the Image Pro-Plus 3.0 program. As measured by time to cell death and change in morphology of OHCs, Cortisporin was most toxic to OHCs. Among the fluoroquinolone drops, Floxin was more toxic than Ciloxan or Cipro HC.

Single ototopical application of mesna has no ototoxic effects on guinea pig cochlear hair cells: a morphological study

Mesna (Mistabron) is a mucolytic substance that is also used for chemically assisted dissection during cholesteatoma surgery. The present animal study aims to evaluate its possible ototoxic side effects. To this end, the right tympanic cavity of 9 guinea pigs was filled with either 20% mesna or 10% neomycin (serving as a positive control), while the left tympanic cavity was filled with saline (serving as a negative control). One week after administration, the inner ears were dissected out and further processed for morphological evaluation by means of either interference contrast microscopy or scanning electron microscopy. No macroscopic signs of middle ear inflammation were observed in any of the ears treated. Whereas damage was obvious in all neomycin-treated specimens, the morphology of both saline- and mesna-treated inner ears was unaffected. These findings led us to conclude that, at least on a morphological basis, no indications are at hand to assume ototoxic effects of this mucolytic substance due to a single application during cholesteatoma surgery.

How easily do topical antibiotics pass through tympanostomy tubes?--an in vitro study

BACKGROUND

Despite potential ototoxicity, eardrops containing aminoglycosides remain in widespread use in the presence of indwelling tympanostomy tubes (grommets). It is unclear how readily they pass into the middle ear during administration, nor whether this is affected by middle ear secretions.

MATERIALS AND METHODS

The trans-tympanic pressure required to force antibiotic solutions through a tympanostomy tube in an artificial middle ear model was investigated with six ototopical preparations and two sizes of tube. To assess the effect of middle ear secretions, tympanostomy tubes removed from patients ears were investigated in addition to new tubes. The intra-canal pressure generated during tragal massage was also measured.

RESULTS

Pressures required for leakage of solutions differed significantly between solutions (P=0.001) and tube sizes, smaller lumen tubes requiring higher trans-tympanic pressure for leakage to occur. The presence of middle ear secretions reduced the pressure required for leakage of solution. Tragal massage generated pressures of over 20 cm of H20 which would be enough to force solution into the middle ear in all tube/solution combinations.

DISCUSSION

Some antibiotic solution is likely to leak into the middle ear during most applications of antibiotic solution. Although the risk is small, this suggests the possibility of ototoxicity, previously demonstrated in animal experiments. The relatively low incidence of this occurrence in clinical practice is thought to be related to inter-species anatomical variations.

Protection against aminoglycoside otic drop-induced ototoxicity by a spin trap: I. Acute effects

Topical administration of aminoglycoside antibiotic drops containing neomycin and polymyxin B disrupts cochlear structure and function in rodents, possibly as a result of reactive oxygen species generation. This study investigated the ability of a spin trap, alpha-phenyl-tert-butyl-nitrone (PBN), to prevent acute aminoglycoside antibiotic drop-induced cochlear dysfunction. Guinea pigs were monitored for compound action potential thresholds and 1.0 microV root-mean-square cochlear microphonic isopotential curve values, then injected intraperitoneally with PBN (60 mg/kg) or saline solution. After 10 minutes, 50 microl of PBN (100 mmol/L) or artificial perilymph was applied to the round window membrane, followed after 10 minutes with artificial perilymph or aminoglycoside antibiotic drops (50 microl). From 10 to 60 minutes after exposure, mean compound action potential thresholds progressively increased in the artificial perilymph-aminoglycoside antibiotic drop group, beginning with high frequencies and later including ever-lower frequencies. These threshold shifts in compound action potentials were significantly greater (p<0.05) than those seen in the artificial perilymph-artificial perilymph or PBN-aminoglycoside antibiotic drop groups. This finding indicates that PBN provided protection against acute aminoglycoside antibiotic drop-induced compound action potential threshold sensitivity loss. Mean cochlear microphonic shift values at 60 minutes in the artificial perilymph-aminoglycoside antibiotic drop group significantly exceeded those of the other groups only at the highest frequencies. These data suggest that acute aminoglycoside antibiotic drop-induced cochlear disruption primarily affects high frequency compound action potential function and may be partially reactive oxygen species-mediated and preventable.

Topical ofloxacin versus systemic amoxicillin/clavulanate in purulent otorrhea in children with tympanostomy tubes

Acute otitis media (AOM) in children with tympanostomy tubes in place typically presents with otorrhea (draining ear). Because therapy is not standardized, various topical and systemic antibiotics of unproven efficacy and safety have been used in this indication. This study compared the safety and efficacy of ofloxacin otic solution, 0.3% (OFLX) with that of Augmentin oral suspension (AUG) in pediatric subjects 1-12 years of age with tympanostomy tubes and acute purulent otorrhea. Subjects were randomized to receive 10d of OFLX, 0.25 ml topically bid, or of AUG, 40 mg/kg per day. Audiometry was performed in subjects > or =4 years of age. Overall cure rate for clinically evaluable subjects was 76% with OFLX (n = 140) and 69% with AUG (n = 146; P = 0.169). Overall eradication rates for OFLX and AUG were similar for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis and were superior with OFLX for Staphylococcus aureus and Pseudomonas aeruginosa (P<0.05 for both). OFLX had a greater overall pathogen eradication rate (96% vs. 67%; P<0.001). Treatment-related adverse event rates were 31% for AUG and 6% for OFLX (P<0.001). Neither treatment significantly altered hearing acuity. Topical ofloxacin 0.3% otic solution 0.25 ml bid was as effective and better tolerated than systemic therapy with Augmentin oral suspension 40 mg/kg per day in treating AOM in children with tympanostomy tubes.

Clinical trial of ototopical ofloxacin for treatment of chronic suppurative otitis media

A multicenter, open-label prospective trial was performed to determine the clinical and microbiologic efficacy of ofloxacin (OFLX) otic solution in the treatment of subjects > or =12 years with chronic suppurative otitis media (CSOM) and a chronically perforated tympanic membrane in the infected ear(s). A total of 207 patients at 27 centers in the United States and Central America received OFLX 0.5 mL instilled ototopically twice daily for 14 consecutive days. The primary clinical end point was cure (dry ear) or failure (not dry ear). The primary microbiologic end point was eradication of baseline pathogens. Because there was no comparator and there were few data in the literature regarding clinical efficacy in patients treated with other regimens, the efficacy of OFLX was compared with data recorded in the clinical records of historical-practice control (HPC) or current-practice control (CPC) subjects. The incidence of clinical cure in clinically evaluable OFLX-treated patients (91%; 148 of 162 subjects) was significantly higher than in HPC subjects (67%; 124 of 185 subjects) or CPC subjects (70%; 38 of 54 subjects). OFLX eradicated all baseline pathogens isolated in microbiologically evaluable subjects. These pathogens were predominantly Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis. The most common treatment-related adverse event, bitter taste, occurred in 17% (35 of 207) of OFLX-treated subjects. Thus OFLX 0.5 mL administered twice daily for 14 days was effective in resolving the signs and symptoms of CSOM in subjects > or =12 years, was significantly more effective than therapies used to treat HPC or CPC subjects, and was well tolerated.

[Otorrhea on transtympanic aerator]

BACKGROUND

Purulent otorrhea is the most common complication of tympanostomy tubes.

POPULATION AND METHODS

Results of culture of otorrhea in 33 consecutive cases were compared to two similar studies performed 4 and 8 years ago in the same institution.

RESULTS

The most frequent organisms were Pseudomonas aeruginosa, Haemophilus influenzae, Staphylococcus aureus and Streptococcus pneumoniae (45, 24, 21 and 15% of the cases, respectively). Such flora resembles that of external otitis and chronic otitis media (P aeruginosa and S pneumoniae).

CONCLUSION

Sensitivity of the organisms encountered in these otorrheas favors the use of topical drops rather than oral antibiotics as the first choice of treatment.