Key messages
– We are uncertain whether topical antibiotics reduce ear discharge of people with swelling and infection of the middle ear (called chronic suppurative otitis media).
– Topical antibiotics may reduce ear discharge compared to placebo (a salt solution), but we are very uncertain. Topical antibiotics used in addition to an antibiotic given by mouth may reduce ear discharge.
– Overall, we are very uncertain which type of topical antibiotic is the most effective.
What is chronic suppurative otitis media?
Chronic suppurative otitis media, also known as chronic otitis media, is a swelling and infection of the middle ear that lasts for two weeks or more. People with chronic suppurative otitis media usually have ear discharge that is difficult to get rid of or keeps coming back (pus that leaks out from a hole in the eardrum) and hearing loss.
How can chronic suppurative otitis media be treated?
Topical antibiotics (administered into the ear canal as ear drops, ointments, sprays, or creams) are the most commonly used treatment for chronic suppurative otitis media. Topical antibiotics kill or stop the growth of the bacteria (germs) that may be responsible for the infection. Topical antibiotics can be used on their own or be added to other treatments for chronic suppurative otitis media, such as antiseptics (which also kill germs) or ear cleaning (aural toileting) or systemic antibiotics (antibiotics taken either by mouth or by an injection into a muscle or vein).
What was the aim of this review?
We wanted to find out how effective topical antibiotics are for people with chronic suppurative otitis media, and whether they cause unwanted effects. We also wanted to know whether one type of topical antibiotic was more beneficial or harmful than any other. In particular, we wanted to know whether topical antibiotics stopped ear discharge, and whether they affected people's quality of life or hearing. We also wanted to know if they caused pain, discomfort, or irritation in the ear; had unwanted effects such as dizziness or ear bleeding; or any serious complications. We compared and summarised the results of the studies and rated our confidence in the evidence, based on factors such as study methods and consistency of results.
What were the main results of the review?
We found one new study (100 participants). Overall, we found 18 studies examining at least 1783 people, but it was difficult to determine precisely how many people were included as some studies did not clearly report the number. Two studies included "mainly children," three included only adults, whilst the remainder appeared to include both children and adults. None of the studies reported the inclusion of people considered at high risk of having chronic suppurative otitis media (for example, people with cleft palate (where the roof of the mouth of a baby does not join together during pregnancy) or Down's syndrome; or people whose immune system does not work well enough to fight germs). The studies used different types of antibiotics and combinations of antibiotics.
Comparison of topical antibiotics to placebo or no treatment
One study (50 people) compared topical antibiotics to a saline (salt water) ear wash. Topical antibiotics may reduce ear discharge more than the saline ear wash when assessed one to up to two weeks after treatment, but we are very uncertain. The evidence is very uncertain about unwanted effects and worsening of hearing measurements. The study did not measure quality of life and reported that there were no serious complications.
Comparison of topical antibiotics in addition to systemic (oral or injected) antibiotics
Four studies (438 people) compared treatment with topical antibiotic (ciprofloxacin) drops in addition to a systemic (oral or injected) antibiotic, but one study did not contribute data. Topical plus oral antibiotics may reduce ear discharge more than oral antibiotics alone at one to up to two weeks and two to up to four weeks. One study stated there were no unwanted effects. The studies did not measure quality of life and did not report any serious complications.
Comparisons of different topical antibiotics
Eight studies (794 participants plus 40 ears) compared an aminoglycoside antibiotic (gentamicin, neomycin, or tobramycin) with a quinolone antibiotic (ciprofloxacin or ofloxacin). Quinolones may reduce ear discharge better than aminoglycosides, but the evidence is very uncertain. One study (100 people) measured ear pain and reported no difference between the groups, but the evidence is very uncertain. Two studies measured hearing loss, but the evidence is very uncertain.
What are the limitations of the evidence?
There were several limitations with the studies. For example, the results varied widely between studies, there were small numbers of people included, there was a lack of recent data, and limited information on groups of people who are more likely to have chronic suppurative otitis media.
How up to date is this review?
This is the first update of a review published in 2020. The evidence is up to date to June 2022.
Read the full abstract
Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media, is a chronic inflammation and often polymicrobial infection (involving more than one micro-organism) of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms are ear discharge and hearing loss. Topical antibiotics, the most common treatment for CSOM, aim to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or with other treatments for CSOM, such as antiseptics or ear cleaning (aural toileting). This is an update of a Cochrane review first published in 2020 and one of a suite of seven reviews evaluating the effects of non-surgical interventions for CSOM.
Objectives
To evaluate the benefits and harms of topical antibiotics (without steroids) for people with chronic suppurative otitis media (CSOM).
Search strategy
We searched the Cochrane ENT Register, CENTRAL, Ovid MEDLINE, Ovid Embase, and five other databases. We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform.
The latest search date was 15 June 2022.
Selection criteria
We included randomised controlled trials with at least a one week of follow-up involving adults and children with chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks.
The interventions were any single, or combination of, topical antibiotic(s) 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 compared to placebo or no intervention, and compared to another topical antibiotic (e.g. topical antibiotic A versus topical antibiotic B).
Data collection and analysis
We used standard Cochrane methodology.
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 and up to four weeks, and after four weeks; health-related quality of life using a validated instrument; and ear pain (otalgia) or discomfort or local irritation. Secondary outcomes were hearing, serious complications, and ototoxicity. We used GRADE to assess the certainty of the evidence for each outcome.
Main results
This update found one new study (100 participants). Overall, we included 18 studies with 1783 participants (in 16 studies), plus 108 ears that could not be accounted for in participant numbers (in two studies).
1. Topical antibiotics versus placebo or no treatment (with aural toilet in both arms and no other background treatment)
One study (50 participants, data unavailable for 15 participants) compared a topical antibiotic (ciprofloxacin) with placebo (saline). All participants received aural toilet.
Topical ciprofloxacin may increase resolution of discharge at one to up to two weeks compared with placebo (84% with antibiotic versus 12% with placebo; risk ratio (RR) 6.74, 95% confidence interval (CI) 1.82 to 24.99; 35 participants; very low-certainty evidence). The study authors reported "no medical side-effects and worsening of audiological measurements related to this topical medication were detected."
2. Topical antibiotics versus placebo or no treatment (with use of oral antibiotics in both arms)
Four studies (438 participants) compared topical antibiotics versus no treatment, with oral antibiotics in both arms. These compared topical ciprofloxacin to no treatment (3 studies, 190 participants) or topical ceftizoxime to no treatment (1 study, 248 participants). In each study, all participants received the same antibiotic systemically (oral ciprofloxacin or injected ceftizoxime). In at least one study, all participants received aural toilet. There were no useable data comparing topical ceftizoxime to no treatment.
Topical antibiotics in addition to systemic antibiotics may increase resolution of ear discharge at one to up to two weeks compared with systemic antibiotics alone (resolution of discharge occurring in 88% with topical antibiotics versus 60% without topical antibiotics; RR 1.47, 95% CI 1.14 to 1.88; 1 study, 100 participants; low-certainty evidence). One study (40 participants) stated "no side effect was recorded in any patient" (low-certainty evidence).
3. Comparisons of different topical antibiotics
Eight studies (794 participants, plus 40 ears) compared aminoglycosides (gentamicin, neomycin, or tobramycin) with quinolones (ciprofloxacin or ofloxacin).
Resolution of discharge at one to up to two weeks may be higher in the quinolones group, but the evidence is very uncertain (RR 1.92, 95% CI 1.00 to 3.67; 7 studies, 794 participants; very low-certainty evidence). There was considerable heterogeneity (I2 = 97%). One study (308 participants) stated there were no differences between the different groups for resolution of ear discharge after four weeks (low-certainty evidence). The evidence is very uncertain about the effects of topical antibiotics on ear pain (1 study reported no differences between groups). The evidence is very uncertain about the effects of topical antibiotics on hearing loss (2 studies reported no differences between groups).
4. Other comparisons
We assessed five studies (501 participants, plus 68 ears) over the following three additional comparisons: quinolones versus aminoglycosides/polymyxin B with/without gramicidin, aminoglycosides versus trimethoprim-sulphacetamide-polymixin B, and rifampicin versus chloramphenicol. However, these results have not been included in the abstract.
Authors' conclusions
We are very uncertain about the effectiveness of topical antibiotics in improving resolution of ear discharge in people with CSOM because of the limited amount of low- or very low-certainty evidence available. This was mostly due to risk of bias and imprecision. However, amongst this uncertainty, there is some evidence to suggest that the use of topical antibiotics may be effective when compared to placebo, or when used in addition to a systemic antibiotic. There is also uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine whether 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, harmful effects were poorly reported. Limitations of the review include lack of recency in data, and limited information on certain population groups or interventions.
