A benefit-risk assessment of ofloxacin otic solution in ear infection

Study on the impurity profile and influencing factors of photodegradation in non-aqueous ofloxacin ear drops using liquid chromatography combined with ion trap/time-of-flight mass spectrometry

Ofloxacin ear drops contain a large proportion of organic solvents, which have a great effect on the photodegradation of ofloxacin. The photodegradation impurities of ofloxacin in aqueous solution has been studied, however, the photodegradation of ofloxacin in non-aqueous solution with a high proportion of organic solvents has not been reported. In this article, the impurity profile in non-aqueous ofloxacin ear drops was studied for further improvement of official monograph in pharmacopoeia and quality control of drug. The liquid chromatography combined with ion trap/time-of-flight mass spectrometry was applied to separate and characterize the structures of the impurities in non-aqueous ofloxacin ear drops. Mass fragmentation pattern of ofloxacin and its impurities were studied. The structures of seventeen impurities in ofloxacin ear drops were elucidated based on the high-resolution MSⁿ data in positive ion modes, and ten of them were unknown impurities. The results showed that the impurity profile of non-aqueous ofloxacin solution was significantly different from that of aqueous ofloxacin solution. The effects of packaging materials and excipients on the photodegradation of ofloxacin ear drops were also investigated. The results of correlation analysis showed that the packaging materials with low light transmittance could reduce the light degradation, and ethanol of excipients could significantly decrease the light stability of ofloxacin ear drops. This study revealed the impurity profile and key factors affecting the photodegradation of non-aqueous ofloxacin ear drops, and guided enterprises to improve drug prescription and packaging materials to ensure the safety of drug use by the public.

Extended high frequency hearing loss in tinnitus-positive chronic suppurative otitis media patient

OBJECTIVES

To determine the association between extended high frequency hearing loss and tinnitus in normal cochlear function based on a conventional audiometry chronic suppurative otitis media (CSOM) patient.

DESIGN AND METHODS

A cross-sectional study was conducted on 220 ears diagnosed as having CSOM with an equal number of tinnitus and without tinnitus groups. Only those with normal cochlear function based on conventional pure tone audiometry (250 Hz to 8 kHz) were included. They were further tested for hearing at extended high frequencies of up to 16 kHz. The severity of tinnitus was tested using a tinnitus questionnaire.

RESULTS

The prevalence of extended high frequency hearing loss in the normal cochlear function CSOM patients with tinnitus was 81.8% (95% CI 74.5%, 89.1%), whereas the prevalence in the tinnitus negative group was 30.0% (95% CI 21.3%, 38.7%). There was a significant association between extended high frequency hearing loss and tinnitus in CSOM patients (P < .001). The average thresholds were significantly higher in the tinnitus group at all extended high frequencies tested with an increasing trend of significance toward the higher frequencies. However, this study did not observe any association between the severity of tinnitus and extended high frequency hearing loss.

CONCLUSION

The development of tinnitus among normal cochlear function CSOM patients indicates that the damage has occurred at a higher frequency level. However, the severity of tinnitus does not predict the degree of higher frequency hearing loss. Therefore, the presence of tinnitus warrants more aggressive monitoring and treatment to prevent sensorineural hearing loss from developing into the speech frequencies.

LEVEL OF EVIDENCE

4.

Why are ototopical aminoglycosides still first-line therapy for chronic suppurative otitis media? A systematic review and discussion of aminoglycosides versus quinolones

Objective:

This systematic review aimed to establish that quinolones are as effective as aminoglycosides when used to treat chronic suppurative otitis media.

Method:

The review included good quality, randomised, controlled trials on human subjects, published in English, that compared topical aminoglycosides with topical quinolones for the treatment of chronic suppurative otitis media.

Results:

Nine trials met the criteria. Two studies showed a higher clinical cure rate in the quinolone group (93 per centvs71 per cent,p= 0.04, and 76 per centvs52 per cent,p= 0.009). Four studies showed no statistically significant difference in clinical outcome. A significant difference in microbiological clearance in favour of quinolones was shown in two studies (88 per centvs30 per cent,p< 0.001, and 88 per centvs30 per cent,p< 0.001).

Conclusion:

Topical quinolones do not carry the same risk of ototoxicity as aminoglycosides. Furthermore, they are equal or more effective in treating chronic suppurative otitis media and when used as prophylaxis post-myringotomy. Topical quinolones should be considered a first-line treatment for these patients.

Management of granular myringitis: A systematic review

Introduction:

Granular myringitis is a chronic disorder characterised by lateral squamous de-epithelialisation and granulation of the tympanic membrane. Untreated, granular myringitis can lead to post-inflammatory medial external auditory canal fibrosis, acquired canal atresia and inflammatory infiltration of the deep canal.

Aim:

This study aimed to establish optimal management strategies which could be applied to clinical practice, through systematic review of the current literature.

Methods:

Current literature was obtained by searching evidence-based medical databases, the Cochrane database, the Database of Abstracts of Reviews of Effects, the Cochrane controlled trials register, Ovid Medline, the variousBritish Medical Journalimprint journals, individual journal websites and citation indexes, and by hand-searching current journals. Detailed inclusion criteria were set. Data were retrieved from the selected studies and checked for accuracy and consistency. The primary outcome measured was the effect of the proposed intervention on recurrence of granular myringitis, compared with empirical antibiotic therapy.

Results:

Fifty-eight publications were identified, dating from 1964 to 2005; 46 of these were potentially relevant. After assessment using the preset inclusion criteria, only two studies remained. El-Seifi and Fouad (2000) found that surgical excision of granulation tissue resulted in an 80 per cent reduction in recurrence of granular myringitis when compared with conventional antibiotic therapy. However, Junget al.(2002) demonstrated a 96 per cent reduction in granular myringitis recurrence when managed with dilute vinegar solution.

Conclusions:

There was a reduced recurrence of granular myringitis in both studies' intervention groups, although neither study was randomised or blinded, making it difficult to assess the clinical relevance of the results. However, the following conclusions can be inferred. (1) Conventional topical antibiotic and steroid drops appear to be less efficacious and more likely to lead to recurrence of symptoms, compared with other proposed treatment modalities. (2) Treatment with dilute vinegar solution presents a logical, unharmful alternative to conventional antibiotic drops. Further research of high value is needed.

Understanding drug ototoxicity: molecular insights for prevention and clinical management

Ototoxicity is a trait shared by aminoglycoside and macrolide antibiotics, loop diuretics, platinum-based chemotherapeutic agents, some NSAIDs and antimalarial medications. Because their benefits in combating certain life-threatening diseases often outweigh the risks, the use of these ototoxic drugs cannot simply be avoided. In this review, the authors discuss some of the most frequently used ototoxic drugs and what is currently known about the cell and molecular mechanisms underlying their noxious effects. The authors also provide suggestions for the clinical management of ototoxic medications, including ototoxic detection and drug monitoring. Understanding the mechanisms of drug ototoxicity may lead to new strategies for preventing and curing drug-induced hearing loss, as well as developing new pharmacological drugs with less toxic side effects.

A comparative study of two antimicrobial/anti-inflammatory formulations in the treatment of canine otitis externa

The efficacy and tolerability of a marbofloxacin-clotrimazole-dexamethasone otic suspension (MCD) was compared with a standard topical treatment using a phase III clinical trial protocol. In a total of 140 dogs with clinical signs of acute or subacute otitis externa, Staphylococcus, Pseudomonas, Enterobacteriaceae and Malassezia were isolated from samples taken at inclusion to identify the causative pathogen; a further sample was collected in the event of failure or relapse, and from dogs (at day 14) for which Pseudomonas species had been isolated at inclusion. One group received MCD (10 drops per affected ear) once daily and a second received Surolan (containing polymyxin B, miconazole and prednisolone) (5 drops per affected ear), twice daily. Each group received treatment for 7 or 14 days according to the clinical outcome on day 7. Efficacy and tolerability were evaluated on days 7, 14 and, if necessary, 28 for dogs treated for 14 days. The trial demonstrated equivalence of both treatments in terms of efficacy, with a cure rate of 58.3% for MCD and 41.2% for Surolan. Both medications were equally well tolerated by dogs, but MCD was superior in terms of pain relief, decrease in pus quantity and smell, response rate and investigator's assessment on day 14.