Ciprofloxacin 0.3% + dexamethasone 0.1% for the treatment for otitis media

Impact of ciprofloxacin/dexamethasone on pediatric tracheostomy outcomes

OBJECTIVE(S)

To investigate the effectiveness of ciprofloxacin/dexamethasone in reducing granulation tissue post-tracheostomy in pediatric patients.

METHODS

This cohort study examined pediatric patients with a tracheostomy at a single academic institution from 2016 to 2020. Exclusion criteria included: deceased within 1 year (n = 38), >16 years of age (n = 21), decannulated within 1 year (n = 15), lost to follow-up within 1 year (n = 6), and revision tracheostomy (n = 2). Logistic regression or Wilcoxon rank-sum (α = 0.05) were used to compare demographic and clinical characteristics between patients who did and did not receive ciprofloxacin/dexamethasone within 1 year of their tracheostomy.

RESULTS

In this cohort, (n = 126, median age 5.2 months, 54.0 % male), 62.7 % received ciprofloxacin/dexamethasone within 1 year, with 27.8 % taking the nebulized form. Granulation tissue occurred in 81.0 % of cases, predominantly peristomal (69.8 %) and suprastomal (34.9 %). Notable complications included accidental decannulation (13.6 %), suprastomal collapse (11.2 %), and bleeding (7.2 %). Although granulation tissue was more common in ciprofloxacin/dexamethasone users (92.4 %) versus non-users (61.7 %) (OR: 7.55, 95 % CI: 2.73-20.9, p < 0.001), patients exhibited less frequent granulation tissue events after initiation (z = 3.88, p < 0.001). No significant differences in antibiotic resistance (p = 1.0) or endocrinology complications (p = 0.1) were found between those with and without ciprofloxacin/dexamethasone.

CONCLUSIONS

We found a statistically significant reduction of granulation tissue incidence with ciprofloxacin/dexamethasone use and no significant differences in antibiotic resistance or endocrinology complications were noted. Future investigation is warranted to explore timing of ciprofloxacin/dexamethasone administration for granulation tissue and its role in managing and preventing tracheostomy complications.

Assessing National Trends and Perceived Safety of Off-Label Ciprofloxacin-Dexamethasone Use by Pediatric Otolaryngologists

OBJECTIVES

Off-label use of Ciprodex® (ciprofloxacin-dexamethasone: CPD), an antibiotic-steroid combination solution, in the airway has been reported by pediatric otolaryngologists with anecdotal success. We examined national trends regarding off-label CPD use including prevalence, common indications, prescriber patterns, adverse events, and accessibility.

METHODS

15-item cross-sectional survey was distributed to American Society of Pediatric Otolaryngology members from January-April 2022. Univariate analyses were performed to compare responses for users of off-label CPD versus non-users. Ease of access was compared across geographies and practice types using multivariate logistic regressions.

RESULTS

Of the 163 complete responses (26.6% response rate), 156 (95.7%) reported using off-label CPD. Most common indications for off-label CPD were tracheal granulation (87.8%, n = 137) and choanal atresia (82.1%, n = 128). Ease of access was significantly increased in the Midwest (OR:18.79, 95%CI:3.63-1.24, p = 0.001) and West (OR:29.92, 95%CI:3.55-682.00, p = 0.006). Ease of access was significantly lower at tertiary referral centers (OR:0.11, 95%CI:0.01-0.64, p = 0.041) and private practices (OR:0.04, 95%CI:0.002-0.33, p = 0.009) compared to academic free-standing children's hospitals. Two-thirds of respondents reported feeling "Very Comfortable" with the safety profile of off-label CPD; 99.4% (n = 156) felt that the benefits outweighed the risks of off-label use. Seven respondents (4.5%) reported adverse events (e.g., local allergic reaction, cushingoid symptoms) from off-label use.

CONCLUSIONS

Our findings (26.6% response rate) suggest that off-label CPD is commonly used by pediatric otolaryngologists, many of whom reported feeling that the benefits of off-label CPD outweigh the risks. Our results establish a baseline for future efforts to assess the efficacy and safety of off-label CPD and to improve its accessibility.

LEVEL OF EVIDENCE

V Laryngoscope, 134:2922-2930, 2024.

Gold nanocluster adjuvant enables the eradication of persister cells by antibiotics and abolishes the emergence of resistance

Persister cells are responsible for relapses of infections common in cystic fibrosis and chronic suppurative otitis media (CSOM). Yet, there are no Food and Drug Administration (FDA) approved antibiotics to eradicate persister cells. Frustratingly, the global preclinical bacterial pipeline does not contain antibacterial agents targeting persister cells. Therefore, we report a nontraditional antimicrobial chemotherapy strategy based on gold nanoclusters adjuvant to eradicate persister cells by existing antibiotics belonging to that different class. Compared to killing with antibiotics alone, combining antibiotics and AuNC@CPP sterilizes persister cells and biofilms. Enhanced killing of up to 4 orders of magnitude in a validated mouse model of CSOM with Pseudomonas aeruginosa infection was observed when combining antibiotics and AuNC@CPP, informing a potential approach to improve the treatment of CSOM. We established that the mechanism of action of AuNC@CPP is due to disruption of the proton gradient and membrane hyperpolarization. The method presented here could compensate for the lack of new antibiotics to combat persister cells. This method could also benefit the current effort to slow resistance development because AuNC@CPP abolished the emergence of drug-resistant strains induced by antibiotics.

Characterization of Ciprofloxacin Resistance Levels: Implications for Ototopical Therapy

HYPOTHESIS

Ciprofloxacin-resistant pathogens are inhibited by high concentrations of ciprofloxacin found in commercially-available ototopical solutions.

BACKGROUND

Ciprofloxacin-resistant pathogens in otitis media are currently treated with ototopical ciprofloxacin suspensions. This is done irrespective of laboratory-reported ciprofloxacin susceptibility, under the assumption that the high concentration of ciprofloxacin applied topically is sufficient to overcome antimicrobial resistance.

METHODS

We evaluated 34 ciprofloxacin-resistant isolates consisting of Staphylococcus aureus, Pseudomonas aeruginosa, Corynebacterium spp., and Turicella otitidis. Ciprofloxacin minimum inhibitory concentration (MIC) assays and clinical ototopical solution minimum bactericidal concentration (CMBC) assays were performed.

RESULTS

Amongst the ciprofloxacin-resistant isolates, ciprofloxacin MICs ranged from 8 to 256 mcg/ml (mean: 87.1 mcg/ml) and CMBCs ranged from 23.4 to 1500 mcg/ml (mean: 237.0 mcg/ml). There were no significant differences with respect to MIC in comparing P. aeruginosa versus Corynebacterium spp. (mean: 53.3 versus 55.2, p = 0.86), S. aureus versus P. aeruginosa (mean: 128.0 versus 53.3, p = 0.34), and S. aureus versus Corynebacterium spp. (mean: 128.0 versus 55.2, p = 0.09). The correlation between ciprofloxacin MIC and CMBC was poor (Pearson's r = -0.08, p = 0.75).

CONCLUSIONS

Ciprofloxacin-resistant pathogens commonly recovered from otitis media exhibit highly variable ciprofloxacin MIC and CMBC levels. Ciprofloxacin was able to inhibit growth in all isolates tested at MIC levels less than or equal to 256 mcg/ml; however, CMBC's up to 1500 mcg/ml were observed within that same group. The clinical relevance of these in vitro MICs is unclear due in part to higher bactericidal concentrations (CMBC) in several strains. Our results suggest that treatment failures may be due to a combination of factors rather than high-level resistance alone.

An extended release ciprofloxacin/dexamethasone hydrogel for otitis media

OBJECTIVE

Otitis media and associated otorrhea are frequent complications following tympanostomy tube insertion; the most common otologic procedure performed in children in the United States. Current treatments include the administration of antibiotic or antibiotic/anti-inflammatory combination drops to the affected ear. Several studies have demonstrated that using an antibiotic/anti-inflammatory combination product is more effective than the use of antibiotics alone. However, administration of any drops through the tympanostomy tube is very difficult in children, and patient compliance can be an issue. Our group has developed a novel combination drug/hydrogel formulation for the treatment of otitis media/otorrhea that releases both ciprofloxacin and dexamethasone over a 2-3 week period. This has the potential to offer significant advantages over current treatments in use in the clinic.

METHODS

The release of drugs from the combination hydrogel was validated in vitro over the desired time frame and the activity of the released drugs was monitored via assays to confirm retention of full activity throughout the dissolution period. The safety of the ciprofloxacin/dexamethasone hydrogel and its inactive excipients was evaluated through in vivo otic toxicity studies in guinea pigs, including hearing tests, gross microscopy, and cytocochleogram analysis.

RESULTS

Extended release of both drugs was demonstrated in vitro and antibiotic/anti-inflammatory activities were retained. The hydrogel components and its excipients did not cause adverse reactions in animals, demonstrating safety of the hydrogel combination in vivo.

CONCLUSION

The studies presented lay the groundwork for extended release middle ear hydrogel formulations that are capable of safely releasing combinations of active pharmaceutical agents over a desired period of time. This would be more advantageous than therapeutics that are currently used in the clinic for the treatment of otitis media/otorrhea associated with tympanostomy tube insertion.

Drug-Induced Ototoxicity: A Comprehensive Review and Reference Guide

OBJECTIVE

In an era of increasing polypharmacy, adverse drug effects such as ototoxicity have significant public health implications. Despite the availability of evidence, many health care professionals may not know the risk of ototoxicity in common medications. Therefore, the aim of this review is to provide a comprehensive, easy to use, ototoxic profile of medications with an assessment of supporting evidence.

METHODS

Medications of interest were identified through adverse drug reaction reports derived from Micromedex (IBM), Lexicomp (Wolters Kluwer), and the textbook, Drug Induced Diseases: Prevention, Detection, and Management. Additional evidence was identified though a query of PubMed and the Cochrane database. Evidence of causality was graded according to the following: A (randomized, controlled clinical trials), B (nonrandomized clinical trials, prospective observational studies, cohort studies, retrospective studies, case-controlled studies, and/or postmarketing surveillance studies), and C (case reports/case series).

RESULTS

A total of 194 systemically administered medications associated with ototoxicity were identified, most commonly antimicrobials (53), psychotropics (21), antihypertensive/antiarrhythmics (19), nonsteroidal antiinflammatory drugs (18), and antineoplastics (16). There was evidence of cochleotoxicity in 165 medications (evidence grading A [22], B [77], C [69]), vestibulotoxicity in 100 medications (evidence grading A [23], B [47], and C [30]), and dizziness in 142 medications (evidence grading A [50], B [76], and C [16]). In addition, a review of the evidence of ototoxicity in ototopical medications is also reviewed.

CONCLUSION

The effect and severity of ototoxicity can vary immensely depending on pharmacological and individual patient risk factors. The intent of this comprehensive review was to help health care providers of all sectors obtain a deeper knowledge of drug-induced ototoxicity to make more informed management decisions for their patients.

Topical antibiotics with steroids for chronic suppurative otitis media

BACKGROUND

Chronic suppurative otitis media (CSOM) is a chronic inflammation and often polymicrobial infection of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Topical antibiotics act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or in addition to other treatments for CSOM, such as steroids, antiseptics or ear cleaning (aural toileting). Antibiotics are commonly prescribed in combined preparations with steroids.

OBJECTIVES

To assess the effects of adding a topical steroid to topical antibiotics in the treatment of people with chronic suppurative otitis media (CSOM).

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with at least a one-week follow-up involving participants (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The interventions were any combination of a topical antibiotic agent(s) of any class and a topical corticosteroid (steroid) of any class, applied directly into the ear canal as ear drops, powders or irrigations, or as part of an aural toileting procedure. The two main comparisons were topical antibiotic and steroid compared to a) placebo or no intervention and b) another topical antibiotic.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. Our primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at between one week and up to two weeks, two weeks to up to four weeks and after four weeks; health-related quality of life; ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity.

MAIN RESULTS

We included 17 studies addressing 11 treatment comparisons. A total of 1901 participants were included, with one study (40 ears) not reporting the number of participants recruited, which we therefore could not account for. No studies reported health-related quality of life. The main comparisons were: 1. Topical antibiotics with steroids versus placebo or no treatment Three studies (210 participants) compared a topical antibiotic-steroid to saline or no treatment. Resolution of discharge was not reported at between one to two weeks. One study (50 'high-risk' children) reported results at more than four weeks by ear and we could not adjust the results to by person. The study reported that 58% (of 41 ears) resolved with topical antibiotics compared with 50% (of 26 ears) with no treatment, but the evidence is very uncertain. One study (123 participants) noted minor side effects in 16% of participants in both the intervention and placebo groups (very low-certainty evidence). One study (123 participants) reported no change in bone-conduction hearing thresholds and reported no difference in tinnitus or balance problems between groups (very low-certainty evidence). One study (50 participants) reported serious complications, but it was not clear which group these patients were from, or whether the complications occurred pre- or post-treatment. One study (123 participants) reported that no side effects occurred in any participants (very low-certainty evidence). 2. Topical antibiotics with steroids versus topical antibiotics (same antibiotics) only Four studies (475 participants) were included in this comparison. Three studies (340 participants) compared topical antibiotic-steroid combinations to topical antibiotics alone. The evidence suggests little or no difference in resolution of discharge at one to two weeks: 82.7% versus 76.6% (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.96 to 1.21; 335 participants; 3 studies (4 study arms); low-certainty evidence). No results for resolution of discharge after four weeks were reported. One study (110 participants) reported local itchiness but as there was only one episode in each group it is uncertain whether there is a difference (very low-certainty evidence). Three studies (395 participants) investigated suspected ototoxicity but it was not possible to determine whether there were differences between the groups for this outcome (very low-certainty evidence). No study reported serious complications. 3. Topical antibiotics with steroids compared to topical antibiotics alone (different antibiotics) Nine studies (981 participants plus 40 ears) evaluated a range of comparisons of topical non-quinolone antibiotic-steroid combinations versus topical quinolone antibiotics alone. Resolution of discharge may be greater with quinolone topical antibiotics alone at between one to two weeks compared with non-quinolone topical antibiotics with steroids: 82.1% versus 63.2% (RR 0.77, 95% CI 0.71 to 0.84; 7 studies; 903 participants, low-certainty evidence). Results for resolution of ear discharge after four weeks were not reported. One study (52 participants) reported usable data on ear pain, two studies (419 participants) reported hearing outcomes and one study (52 participants) reported balance problems. It was not possible to determine whether there were significant differences between the groups for these outcomes (very low-certainty evidence). Two studies (149 participants) reported no serious complications (very low-certainty evidence).

AUTHORS' CONCLUSIONS

We are uncertain about the effectiveness of topical antibiotics with steroids in improving the resolution of ear discharge in patients with CSOM because of the limited amount of low-certainty evidence available. Amongst this uncertainty, we found no evidence that the addition of steroids to topical antibiotics affects the resolution of ear discharge. There is also low-certainty evidence that some types of topical antibiotics (without steroids) may be better than topical antibiotic/steroid combinations in improving resolution of discharge. There is also uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine with any certainty whether or not quinolones are better or worse than aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.

Potential Ototopical Antiseptics for the Treatment of Active Chronic Otitis Media: An In Vitro Evaluation

OBJECTIVES

Primary: to compare, in vitro, the antimicrobial activity of different antiseptic agents versus quinolone drops, against the common organisms of chronic otitis media.Secondary: to examine the possible role of pH on the antimicrobial activity of the antiseptic solutions.

METHODS

Three antiseptic powders (boric acid; iodine; and a 1:1 combination of these two) and four solutions (2% boric acid; 2% acetic acid; 3.25% aluminum acetate; and 5% povidone iodine) were tested against five bacteria and two fungi common in chronic otitis media, using both agar plates and the modified broth dilution method. These results were compared with the antimicrobial activity of quinolone drops.The potential role of pH of solutions was tested by reducing the acidity of the agents and repeating the broth dilution.

RESULTS

Of the powders, iodine, and iodine/boric acid combined, are very effective against all organisms. Boric acid powder showed moderate effectiveness against all organisms. All solutions performed poorly on the agar plates. 5% povidone iodine has good effectivity when tested with the broth dilution method. 3.25% aluminum acetate had the best activity against Pseudomonas aeruginosa.

CONCLUSION

Boric acid powder and 5% povidone iodine solution show promise for clinical use. Boric acid powder has proven clinical effectiveness. 5% povidone iodine requires further clinical research. Although very effective in vitro, iodine powder is toxic to tissues and cannot be recommended for clinical use. The pH of solutions does not seem to play a significant role in their antimicrobial activity in vitro.

Tympanostomy Tube Placement vs Medical Management for Recurrent Acute Otitis Media in TRICARE-Insured Children

Objective To compare number of infections and health care utilization in children insured by TRICARE with recurrent acute otitis media (RAOM) managed surgically with tympanostomy tube (TT) placement compared with those managed medically. Study Design Retrospective matched cohort study. Setting TRICARE claims database from 2006 to 2010. Subjects and Methods We matched TRICARE beneficiaries ≤5 years of age diagnosed with RAOM who underwent TT placement with those managed medically using 1:1 coarsened-exact matching on age, sex, race, sponsor rank, and region. We used multivariable negative binomial regression to compare number of infections and health care utilization at 1 and 2 years. Outcomes were adjusted for rate of infection before treatment for RAOM, season of either TT placement or establishment of candidacy for TT placement, and comorbidities. Results Among 6659 pairs identified at 1-year follow-up, the TT group had fewer infections (1.96 vs 2.18, P < .001) and oral antibiotic prescriptions (1.52 vs 1.67, P < .001) but more visits to primary care physicians (4.36 vs 4.06, P < .0001) and otolaryngologists (1.21 vs 0.44, P < .0001) compared with the medically managed group. At 2-year follow-up, the benefits of TT placement were no longer seen. Conclusion TT placement for RAOM is associated with fewer infections and oral antibiotic prescriptions in the first year after surgery but more doctor visits. Benefits of TT placement do not appear to extend through the second year. Future research should investigate costs associated with TT placement vs medical management, as well as real-time health care utilization with impact on patient symptoms and quality of life.

Dexamethasone modulation of MUC5AC and MUC2 gene expression in a generalized model of middle ear inflammation

OBJECTIVES/HYPOTHESIS

To examine the effect of dexamethasone on basal and proinflammatory cytokine-induced gel-forming mucin expression in human middle ear epithelial cell line (HMEEC-1).

METHODS

HMEEC-1 was exposed to proinflammatory cytokines, tumor necrosis factor-alpha (TNF-), and interleukin-1 beta (IL-1β) to identify optimal mucin induction. The HMEEC-1 was incubated with dexamethasone in the steady state and in the presence of proinflammatory cytokine stimulation. Expression of MUC2 and MUC5AC was determined by quantitative polymerase chain reaction.

RESULTS

Proinflammatory cytokines, TNF-α and IL-1β, induced MUC2 and MUC5AC expression in HMEEC-1. Dexamethasone reduced steady state mRNA level of MUC5AC in a time-dependent (P < 0.05) and dose-dependent (P < 0.0001) manner. MUC2 was effectively suppressed at all time points tested (P < 0.05). Temporal difference between dexamethasone suppression of MUC2 and MUC5AC was demonstrated. Dexamethasone inhibits the proinflammatory cytokine-induced expression of both MUC2 and MUC5AC.

CONCLUSION

This work provides a conclusive picture of the ability of using glucocorticoids to downregulate mucin gene expression in human MEE using a generalizable model of inflammation that is applicable to multiple potential causes of MEE mucosal hypertrophy. This data adds to the promising potential of future interventions for patients with chronic otitis media.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 126:E248-E254, 2016.

Topical versus oral antibiotics, with or without corticosteroids, in the treatment of tympanostomy tube otorrhea

OBJECTIVE

Antibiotic treatment is the standard of care for tympanostomy tube otorrhea. This meta-analysis aims to evaluate the efficacy of topical antibiotics with or without corticosteroids versus oral antibiotics in the treatment of tube otorrhea in children.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and ProQuest.

REVIEW METHODS

The above databases were searched using a search strategy for randomized controlled trials for optimal treatment of tube otorrhea in the pediatric population. PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines were followed. Primary outcome was cure (i.e. clearance of otorrhea) at 2-3 weeks. Secondary outcomes were microbiological eradication and complications such as dermatitis and diarrhea. The incidence of these events was defined as dichotomous variables and expressed as a risk ratio (RR) and number needed to benefit (NNTB) in a random-effects model.

RESULTS

We identified 1491 articles and selected 4 randomized controlled trials which met our inclusion criteria. Topical treatment had better cure (NNTB = 4.7, pooled RR = 1.35, p < 0.001) and microbiological eradication (NNTB = 3.5, pooled RR = 1.47, p < 0.001 among 3 of the studies) than oral antibiotics. Oral antibiotics had higher risk of diarrhea (pooled RR = 21.5, 95% CI 8.00-58.0, p < 0.001, Number needed to harm (NNTH) = 5.4) and dermatitis (pooled RR = 3.14, 95% CI 1.20-8.20, p = 0.019, NNTH = 32). The use of topical steroids in addition to topical antibiotics was associated with a higher cure rate (pooled RR = 1.59, p < 0.001 vs pooled RR = 1.57, p = 0.293).

CONCLUSION

Topical antibiotics should be the recommended treatment for management of tympanostomy tube otorrhea in view of its significantly improved clinical and microbiological efficacy with lower risk of systemic toxicity as compared to oral antibiotics. Further research is necessary to confirm the benefits of topical corticosteroids as an adjunct to topical antibiotics.

Recovery time for inflamed middle ear mucosa in chronic otitis media

CONCLUSION

The present study shows that 2-3 weeks after medical treatment the status of middle ear mucosa in draining ears is similar to that of dry ears for at least 3 months.

OBJECTIVE

To measure the time required for an inflamed middle ear mucosa to return into optimal state after appropriate medical treatment in chronic suppurative otitis media (CSOM). To assess optimal timing for elective surgical treatment of draining ears in uncomplicated CSOM.

METHODS

In this prospective study, the Eustachian tube (ET) mucociliary clearance time (MCT) was used as the method to demonstrate the status of middle ear mucosa. In group 1 (28 patients) ET-MCT was measured in ears that were free of drainage for at least 3 months. In Group 2 (21 patients), ET-MCT was measured in draining ears, who responded to 10-14 days medical treatment, at presentation, after 10 days and 1 month.

RESULTS

The ET-MCT was 8.63 ± 1.32 min in group 1 and 28.96 ± 8.19 min in group 2 at presentation; and the difference was statistically significant (p < 0.001). The ET-MCT was 14.76 ± 5.11 min after 10 days and 9.31 ± 2.33 min after 1 month in group 2. The ET-MCT was indifferent between groups 1 and 2 after 1 month (p = 0.235).

Determination of the glycosylation-pattern of the middle ear mucosa in guinea pigs

In the present study the glycosylation pattern of the middle ear mucosa (MEM) of guinea pigs, an approved model for middle ear research, was characterized with the purpose to identify bioadhesive ligands which might prolong the contact time of drug delivery systems with the middle ear mucosa (MEM). To assess the utility of five fluorescein labeled plant lectins with different carbohydrate specificities as bioadhesive ligands, viable MEM specimens were incubated at 4°C and the lectin binding capacities were calculated from the MEM-associated relative fluorescence intensities. Among all lectins under investigation, fluorescein-labeled wheat germ agglutinin (F-WGA) emerged as the highest bioadhesive lectin. In general, the accessibility of carbohydrate moieties of the MEM followed the order: sialic acid and N-acetyl-d-glucosamine (WGA)>>mannose and galactosamine (Lensculinaris agglutinin)>N-acetyl-d-glucosamine (Solanumtuberosum agglutinin)>fucose (Ulexeuropaeus isoagglutinin I)>>terminal mannose α-(1,3)-mannose (Galanthusnivalis agglutinin). Competitive inhibition studies with the corresponding carbohydrate revealed that F-WGA-binding was inhibited up to 90% confirming specificity of the F-WGA-MEM interaction. The cilia of the MEM were identified as F-WGA binding sites by fluorescence imaging as well as a z-stack of overlays of transmission, F-WGA- and nuclei-stained images of the MEM. Additionally, co-localisation experiments revealed that F-WGA bound to acidic mucopolysaccharides of the MEM. All in all, lectin-mediated bioadhesion to the MEM is proposed as a new concept for drug delivery to prolong the residence time of the drug in the tympanic cavity especially for successful therapy for difficult-to-treat diseases such as otitis media.