The Effect of Antibiotic Eye Drops on the Nasal Microbiome in Healthy Subjects

NCT ID: NCT05287425

Last Updated: 2025-05-16

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

PHASE2

Total Enrollment

20 participants

Study Classification

INTERVENTIONAL

Study Start Date

2019-08-12

Study Completion Date

2023-08-28

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Ophthalmic topical antibiotics are commonly prescribed in clinical practice for several indications such as bacterial conjunctivitis, keratitis, blepharitis, dacryocystitis and also as prophylaxis. Aminoglycosides (i.e. gentamicin) and fluoroquinolones (i.e. ciprofloxacin) are among the most frequently used substance classes.

There is evidence that topical non-antibiotic eye drops might have an effect on the nasopharyngeal mucosal flora. This seems logical due to the anatomical connection through the nasolacrimal duct and the fact that up to 80% of topically administered drug diffuse into the systemic circulation through the highly vascularized nasopharyngeal mucosa. However, in the literature no data on the effect of antibiotic eye drops on the nasal or pharyngeal microbiome are currently available.

Recently, new, non-culture based techniques for assessment of the bacterial microbiome have been developed, so-called "next-generation sequencing" (NGS). NGS utilizes universal primers targeting the 16S rRNA gene, which is ubiquitous across most bacteria. With this technique, it is possible to gain information about a wide range of the bacterial microbiome and not only on pre-selected species.

In the present study, NGS will be used to investigate the effect of antibiotic eye drops on the nasal and pharyngeal microbiome. For this purpose, healthy subjects will be randomized to either receive eye drops containing gentamicin, ciprofloxacin or topical lubricants as control. As secondary outcome, prevalence of bacterial resistance genes, as well as signs and symptoms of ocular surface damage will be assessed.

The study will be carried out in 2 parts. Since both formulations of topical antibiotics contain benzalkonium chloride which also has a potential effect on the nasal and pharyngeal mucosal flora, it is unknown how much benzalkonium chloride would contribute to changes in the nasal microbiome after administration of topical antibiotics. To overcome this problem, first a pilot study in 20 subjects will be performed in which subjects will be randomized to receive either eye drops containing gentamicin, ciprofloxacin, preservative-containing topical lubricants or preservative-free topical lubricants. Based on the results of this pilot study, the control for the main part of the study will be chosen, depending on the effect on the bacterial microbiome. The results of the pilot study could also provide useful data to adjust the sample size for the main study part. In the main study, 60 subjects will be randomized to receive gentamicin, ciprofloxacin or lubricant eye drops. The same examinations as described above will be performed after 1 week treatment as well as 1 week and 3 months after treatment.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Nasal and Pharyngeal Microbiome

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

DOUBLE

Investigators Outcome Assessors

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Gentamicin eye drops

4 drops daily in both eyes for 7 ± 1 days

Group Type EXPERIMENTAL

Gentamicin Ophthalmic

Intervention Type DRUG

4 drops daily in both eyes for 7 ± 1 days

Ciprofloxacin eye drops

4 drops daily in both eyes for 7 ± 1 days

Group Type EXPERIMENTAL

Ciprofloxacin Ophthalmic

Intervention Type DRUG

4 drops daily in both eyes for 7 ± 1 days

Povidone eye drops unpreserved

4 drops daily in both eyes for 7 ± 1 days

Group Type ACTIVE_COMPARATOR

Povidone Ophthalmic

Intervention Type DRUG

4 drops daily in both eyes for 7 ± 1 days

Povidone eye drops preserved

4 drops daily in both eyes for 7 ± 1 days

Group Type ACTIVE_COMPARATOR

Povidone and Benzalkonium Chloride Ophthalmic

Intervention Type DRUG

4 drops daily in both eyes for 7 ± 1 days

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Gentamicin Ophthalmic

4 drops daily in both eyes for 7 ± 1 days

Intervention Type DRUG

Ciprofloxacin Ophthalmic

4 drops daily in both eyes for 7 ± 1 days

Intervention Type DRUG

Povidone Ophthalmic

4 drops daily in both eyes for 7 ± 1 days

Intervention Type DRUG

Povidone and Benzalkonium Chloride Ophthalmic

4 drops daily in both eyes for 7 ± 1 days

Intervention Type DRUG

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Men and women aged between 18 and 45 years
* Normal ophthalmic findings
* Tear Break Up Time \>10 seconds
* Schirmer I Test \> 10mm/5min
* Ametropia ≤ 6 diopters
* No use of topical eye or nasal drops in the last 3 months

Exclusion Criteria

* Regular use of medication, abuse of alcoholic beverages or drugs
* Participation in a clinical trial in the 3 weeks preceding the study
* Treatment in the previous 3 weeks with any drug (except intake of hormonal contraceptives)
* Treatment with topical or systemic antibiotics within 8 weeks before inclusion
* Symptoms of a clinically relevant illness in the 3 weeks before the first study day
* History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with distribution, metabolism or excretion of study drugs
* Known hypersensitivity to any of the components of the IMP under investigation or other study medication
* Pregnant or breast-feeding women
* Women of childbearing potential (neither menopausal, nor hysterectomized, nor sterilized) not using effective contraception (i.e. oral contraceptives, intra-uterine device, contraceptive implant or condoms)
Minimum Eligible Age

18 Years

Maximum Eligible Age

45 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Medical University of Vienna

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Doreen Schmidl

Assoc. Prof. PD, MD, PhD

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Department of Clinical Pharmacology, Medical University of Vienna

Vienna, Vienna, Austria

Site Status

Countries

Review the countries where the study has at least one active or historical site.

Austria

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

OPHT-240518

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.