Microbiome and Otic Quinolone Levels Following Tympanoplasty Assessed by Gelatin Sponge Analysis

OBJECTIVE

To determine if absorbable gelatin sponge (AGS) can be used to assess the posttympanoplasty microbiome and otic antibiotic exposure.

STUDY DESIGN

Prospective.

SETTING

Tertiary hospital.

METHODS

Patients undergoing tympanoplasty were prospectively enrolled. Intraoperatively, AGS was applied to the medial ear canal/tympanic membrane (TM) for 1 minute after canal incision, then saved for analysis. Ear canals were packed with AGS at the end of surgery. Otic ofloxacin was administered until the first postoperative visit, when AGS was collected. Microbial presence was assessed by culture. Ofloxacin levels were assessed by liquid-chromatography mass-spectrometry.

RESULTS

Fifty-three patients were included. AGS was collected in 92.9% of patients seen within 21 days compared to 70.8% of those seen at 22 to 35 days. At surgery, AGS yielded bacteria and fungi in 81% and 11%, respectively, including Staphylococcus species (55%) and Pseudomonas species (25%). Postoperatively, AGS yielded bacteria in 71% and fungi in 21% at the meatus, (staphylococci 57% and pseudomonas 25%). TM samples yielded bacteria in 69%, fungi in 6%, staphylococci in 53%, and pseudomonas in 19%. Ofloxacin concentration at the meatus was 248 μg/mL (95% confidence interval [CI]: 119-377) and at the TM was 126 μg/mL (95% CI: 58-194). Ofloxacin-resistant colonies were found in 75% of patients.

CONCLUSION

Analysis of AGS is a viable technique for noninvasively studying healing metrics posttympanoplasty, including the microbiome and otic antibiotic exposure. Despite exposure to a high concentration of quinolones, the tympanoplasty wound is far from sterile, which may impact healing outcomes.

Quinolone Ear Drops and Achilles Tendon Rupture

BACKGROUND

Delayed eardrum healing has been observed in the ear opposite to the ear treated with otic quinolones (OQ) in rats. Case reports describe tendinopathies after OQ treatment, suggesting adverse systemic effects.

METHODS

We studied patients aged 19 to 64 years with diagnosis of otitis externa or media in private insurance between 2005 and 2015. We compared OQ treatment against otic neomycin, oral amoxicillin, or azithromycin. Outcomes included Achilles tendon rupture (ATR), Achilles tendinitis (AT), and all-type tendon rupture (ATTR). We applied an active comparator, new-user design with 1-year look-back and ceased follow-up at initiation of systemic steroids or oral quinolones, external injury, hospitalization, and after 35 days. We used trimmed stabilized inverse probability of treatment weights to balance comparison groups in a survival framework. Negative outcomes (clavicle fractures or sports injuries) were examined to rule out differences from varied physical activity (unmeasured confounding).

RESULTS

We examined 1 501 009 treated otitis episodes. Hazard ratios (HR) for OQ exposure associated with ATR were 4.49 (95% confidence interval [CI], 1.83-11.02), AT 1.04 (95% CI, 0.73-1.50), and ATTR 1.71 (95% CI, 1.21-2.41). Weighted risk differences (RD) per 100 000 episodes for OQ exposure were ATR 7.80 (95% CI, 0.72-14.89), AT 1.01 (95% CI, -12.80 to 14.81), and ATTR 18.57 (95% CI, 3.60-33.53). Corresponding HRs for clavicle fractures and sports injuries were HR,1.71 (95% CI, 0.55-5.27) and HR,1.45 (95% CI, 0.64-3.30), suggesting limited residual confounding.

CONCLUSIONS

OQ exposure may lead to systemic consequences. Clinicians should consider this potential risk and counsel patients accordingly. Risk factors and mechanisms for this rare, adverse effect deserve further evaluation. Mechanistic and other clinical studies are warranted to corroborate this finding.

Safety and Efficacy of Intratympanic Histamine Injection as an Adjuvant to Dexamethasone in a Noise-induced Murine Model

The safety and efficacy of intratympanic (IT) histamine (HIS) injection as an adjuvant to increase the inner ear penetration of dexamethasone (DEX) was investigated in this study. IT injections of DEX-only, 1% HIS+DEX and 4% HIS+DEX were performed in mice with noise-induced hearing loss. An inflammatory reaction in the middle ear was observed only in the 4% HIS+DEX group although no serious cytotoxic effects on the organ of Corti (OC) were observed at that concentration. Compared with the DEX-only group, the perilymphatic concentration of DEX was approximately two times higher in the 1% HIS+DEX group and approximately five times higher in the 4% HIS+DEX group. The expression of the DEX receptor in the cochlea was significantly increased in the 4%-HIS+DEX group. HIS appeared to induce transient damage the microstructure of the RWM with recovery observed within 3 weeks. The 1% and 4% HIS + DEX groups showed a significant recovery of the OC compared with the control group and they also achieved significantly better hearing restoration at 8 kHz in the DPOAE hearing test (P < .05) when compared to the DEX-only group. IT HIS temporarily disrupts the structure of the RWM and middle ear mucosa and significantly enhances the inner ear penetration of DEX. Therefore, IT HIS injection could be a simple and effective adjuvant therapy to increase perilymph concentration of DEX and achieve OC recovery after cochlear damage.

Does intraoperative ciprofloxacin-soaked gelfoam have adverse effects on graft success rate? A randomized, double-blind controlled trial

OBJECTIVES

The aim of this study was to evaluate whether intraoperative ciprofloxacin-soaked gelfoam is safe in tympanoplasty or not.

METHOD

In this randomized, double-blind controlled clinical study, we included 100 patients between 18 and 60 years old, having perforation ≥50% of the tympanic membrane and dry ear for at least 2 months who were a candidate for underlay tympanoplasty via postauricular approach. We used ciprofloxacin soaked gelfoam in the case group and betamethasone soaked gelfoam in the control group for packing the middle ear cavity and external auditory canal during their operation. The graft success rate and tympanogram after 6 months follow-up period was considered as the primary outcome. Also, we evaluated the postoperative hearing results 6 months after the surgery as the secondary outcomes.

RESULTS

Postoperative microscopic otoscopy showed a graft success rate of 100% (44/44) and 97.7% (42/43) in the case and control groups, respectively. The level of improvement between the two groups was not significant for air-bone gap (ciprofloxacin: 9.01 ± 7.89 dB, betamethasone 5.31 ± 10.53 dB, P = .160), and speech reception thresholds (SRT; ciprofloxacin: 10.23 ± 8.62 dB, betamethasone 7.33 ± 12.60 dB, P = .260). 93.2% of all the ears in the case group and 81.4% of those in the control group achieved postoperative air-bone gap within 20 dB, but the difference between them was not significant (P = .118).

CONCLUSIONS

We found that the application of ciprofloxacin impregnated gelfoam in the middle ear, and the external auditory canal had no adverse effect on the graft success rate in tympanoplasty.

LEVELS OF EVIDENCE

1b.

Effects of quinolone and poloxamer otic suspension on rat tympanic membranes

OBJECTIVES

Commercial quinolone ear drops (0.3%) delivered twice daily for 10 days cause tympanic membrane perforations (TMPs) in rats. We aimed to evaluate if a single application of 6% quinolone in poloxamer causes TMPs in rats.

METHODS

Rats were randomized to 5 groups (10/group), with one ear receiving a single otic instillation of 16% poloxamer 407 or 188 (as found in a commercial otic preparation and a wound dressing), or ofloxacin, ciprofloxacin, or neomycin at 6% in suspension with 16% poloxamer 407. The contralateral ear received saline. Rats were assessed over 42 days.

RESULTS

No TMPs were seen in ears treated with saline, poloxamer 407 or 188, or in ears treated with ofloxacin-, ciprofloxacin-, or neomycin-poloxamer suspension. White precipitates were observed on the canal or tympanic membrane of ciprofloxacin and ofloxacin-treated ears. Precipitates were more common in ciprofloxacin-treated ears until day 10 (p < 0.0001 to p = 0.0004). Tympanic membrane surface irregularities, were also observed mostly in the ciprofloxacin-treated ears from day 3-42 (p = 0.03 to p = 0.0033).

CONCLUSIONS

Quinolone in poloxamer otic preparations may be a safer therapeutic alternative to conventional quinolone ear drops in ears with intact TMs, particularly those felt to be at risk for developing TMPs.

The Influence of Ciprofloxacin-Dexamethasone Ear Drops on Perforation Closure Rates After Endoscopic Tympanoplasty

OBJECTIVE

Topical ciprofloxacin and dexamethasone have both been shown to disrupt healing of tympanic membrane perforations in animal models. There have been no clinical studies evaluating the effect of ciprofloxacin-dexamethasone (CD) ear drops on success of tympanoplasty. We compare perforation closure rates in pediatric endoscopic tympanoplasty with and without use of postoperative CD.

STUDY DESIGN

Retrospective comparative cohort study.

SETTING

Tertiary referral centre.

PATIENTS

One hundred sixty-two totally endoscopic tympanoplasties with porcine-derived collagen graft in children, mean age 12.0 years (range 2.3-17.9 yrs).

INTERVENTION

Prescription of CD versus no ear drops in the immediate postoperative period.

MAIN OUTCOME MEASURE

Perforation closure rate 2 months after totally endoscopic tympanoplasty.

RESULTS

Postoperative CD was given to 65 (40%) ears and no drops given to the remainder. Overall, successful closure of tympanic membrane perforation was achieved in 140 (86%) of ears. The closure rate was not significantly different in those ears given CD postoperatively than those not given CD (54/65 [83%] vs 86/97 [89%], Fisher's p = 0.35). Multiple logistical regression revealed no confounding effect of other variables on outcome including age, revision surgery, graft position, or type of postoperative packing material.

CONCLUSIONS

Our results reveal no harm or benefit with prescription of drops containing ciprofloxacin and dexamethasone on success of perforation closure after tympanoplasty. Allocation to treatment in this retrospective study was nonrandomized and was predominantly based on a change in practice. No other variables are known to have influenced this finding but a randomized prospective study could be justified for more reliable evidence.

The Effects of Steroids on Survival of Mouse and Human Tympanic Membrane Fibroblasts

OBJECTIVE

Tympanic membrane (TM) fibroblast cytotoxicity of quinolone ear drops is enhanced by dexamethasone and fluocinolone. Hydrocortisone has not been evaluated. We aimed to assess the effects of these 3 steroids on mouse and human TM fibroblast survival.

STUDY DESIGN

In vitro.

SETTING

Academic laboratory.

SUBJECTS AND METHODS

Mouse and human TM fibroblasts were exposed to hydrocortisone, dexamethasone, or fluocinolone at concentrations in commercial ear drops (1%, 0.1%, or 0.025%, respectively) and at steroid potency equivalents (1%, 0.033%, or 0.0033%, respectively), or dilute ethanol (control), twice within 24 hours or 4 times within 48 hours for 2 hours each time. Cells were observed with phase-contrast microscopy until the cytotoxicity assay was performed.

RESULTS

Mouse and human TM fibroblasts treated with any of the steroids had lower survival after 24 and 48 hours compared to control (all P < .0001). After 24 hours, viability of mouse fibroblasts treated with the steroids was not different (P > .05), while treatment with hydrocortisone decreased human TM fibroblast viability (P < .0001). After 48 hours, at concentrations found in ear drops and at equivalent steroid potency, dexamethasone and fluocinolone had similar survival in mouse and human fibroblasts (all P > .05), but hydrocortisone had lower survival in both mouse (P = .02 and P < .0001) and human (P < .0001) fibroblasts. Phase-contrast images mirrored the cytotoxicity findings.

CONCLUSION

Steroids found in commercial ear drops reduce survival of mouse and human TM fibroblasts. Hydrocortisone appears to be more cytotoxic than the more potent steroids, dexamethasone and fluocinolone. These findings should be considered when assessing clinical outcomes of ototopical preparations.

Cytotoxicity of Ear Drop Excipients in Human and Mouse Tympanic Membrane Fibroblasts

Objective

Commercial ear drops contain ingredients reported to be inactive. We sought to evaluate such excipients for possible cytotoxicity on human and mouse tympanic membrane (TM) fibroblasts.

Study Design

Prospective, in vitro.

Setting

Tertiary academic center.

Subjects and Methods

Mouse and human TM fibroblasts were treated with 1:10 dilutions of benzalkonium chloride (BKC) 0.0025%, 0.006%, or 0.01%; benzyl alcohol 0.9%; polysorbate 80 (PSB) 2.5%; glycerin 2.4%; povidone 0.2%; or water (control), twice within 24 hours or 4 times within 48 hours, for 2 hours each time. Cells were placed back in growth media after the treatments. Cells were observed with phase-contrast microscopy until the cytotoxicity assay was performed.

Results

Mouse fibroblasts had lower survival in only the PSB-treated cells compared to the control ( P < .0001) after 24 hours. After 48 hours, PSB killed nearly all mouse fibroblasts ( P < .0001). BKC decreased fibroblast survival in a dose-dependent manner ( P < .001). In human TM fibroblasts, all excipients except povidone and benzyl alcohol after 24 hours and povidone after 48 hours reduced cell survival compared to control ( P = .012 to P < .0001). The cytotoxicity of BKC in human TM fibroblasts was also dose dependent (<.0001). PSB was less cytotoxic to human fibroblasts. Phase-contrast images mirrored the cytotoxicity findings.

Conclusion

Polysorbate 80 and benzalkonium chloride, at concentrations found in commercial ear drops, may be cytotoxic to human and mouse TM fibroblasts. “Inactive” ingredients may need to be considered when evaluating clinical outcomes with commercial ear drops.

Appropriateness of Otic Quinolone Use among Privately Insured US Patients

Objective

Considering emerging safety concerns involving otic quinolones, we assessed the extent of otic quinolone use for questionable indications.

Study Design

Descriptive cross-sectional study of a national sample of privately insured patients.

Setting

Outpatient encounters in the United States.

Subjects and Methods

Children and adults with outpatient pharmacy-dispensing claims for new prescriptions of otic or ophthalmic quinolones in 2017 were identified within the IBM MarketScan Commercial Claims & Encounters and the Medicare Supplemental Database. Each dispensing ≥30 days apart constituted a unique episode. Only claims with supporting ear-related diagnoses on outpatient encounters ±3 days of dispensing were considered. Ophthalmic drops were excluded if eye-related diagnoses were found ±30 days. Prescribing was classified as appropriate, questionable, or undetermined.

Results

We found 214,897 episodes in 200,270 patients. Adults were twice as likely as children to have otic treatment with questionable indications (6.2% vs 3.0%). Sensitivity analyses with broader time windows to ascertain diagnoses showed similar proportions of questionable use. Otalgia and cerumen impaction constituted 90% of questionable indications. Family physicians (6.8%) and internists (8.0%) had higher percentages of questionable use than other specialties.

Conclusion

Based on the demonstrated risks of quinolone ear drops, opportunities exist to decrease otic quinolone use, especially in adults.