This study allowed us to determine the prescription patterns of ophthalmic and systemic medications for the treatment of conjunctivitis in a group of patients affiliated with the Colombian Health System as evidence of drug use in the real world. These findings can be useful to help health care personnel; academics and scientists make decisions regarding the risks that their patients face and can contribute to strengthening the practices related to the rational use of antibiotics and glucocorticoids among physicians in an effort to reduce adverse drug reactions and ophthalmic complications in the country.
We observed that ophthalmic antibiotics were prescribed for more than one third of patients, including a large proportion of those with viral and unspecified conjunctivitis and a smaller proportion of patients with allergic conjunctivitis, for which clinical practice guidelines do not recommend the use of antibiotics [8, 9, 11]. However, the rate of antibiotics prescriptions for acute conjunctivitis is higher in countries such as the USA (58.0-72.7%) [6, 12], Australia (74.0%) , Holland (80.0%)  and Belgium (89.4%)  and lower in different Scandinavian countries (4.2-21.1%) . The present analysis found that the majority of prescriptions were issued by general practitioners, which is consistent with the reports of other publications [6, 12–14]. For example, in England, Everitt et al surveyed general practitioners and found that 95.0% prescribed antibiotics for the management of acute infectious conjunctivitis, but 58.0% of professionals believed that half of their patients had a viral infection . The indiscriminate use of antibiotics can cause severe alterations in the ocular bacterial flora, which is essential for the prevention of ocular infections, and can be associated with an increase in antimicrobial resistance [10, 17].
Differences were found in the most frequently used type of antibiotic. In the present report, a quarter of the patients were prescribed neomycin with polymyxin B and glucocorticoid; this is in contrast with other reports, in which other antibiotics predominated [7, 12–14, 18–21]. For example, the use of polymyxin B with trimethoprim predominated in the USA (53.4%) , whereas it was prescribed with fusidic acid in the Netherlands (69.0%) , levofloxacin in China (71.8%) , chloramphenicol in Australia (50.8%) , moxifloxacin in India (52.0-53.5%) [20, 21] and tobramycin in Spain (66.1%)  and Belgium (23.4%) . The differences in drug prescription patterns have been shown in other pharmacoepidemiological studies in the country, but in different clinical contexts [22–24]. These variations can be explained by the epidemiological heterogeneity among countries in terms of the etiology and resistance patterns of microorganisms, the characteristics of health systems, the accessibility and availability of drugs and the marketing strategies of the pharmaceutical industry [22, 23].
The inappropriate use of antibiotics for conjunctivitis with an etiology other than bacteria can have various causes. Professionals, especially general practitioners, may have difficulty distinguishing cases of viral and allergic conjunctivitis from bacterial cases because the three etiologies can present similar clinical characteristics, such as eye irritation, conjunctival injection and foreign body sensation [1, 4]. In addition, some prescribers may not have appropriate academic training for the correct diagnosis and treatment of acute conjunctivitis . Similarly, the prescription of ophthalmic medications may be associated with sociodemographic characteristics of the patient, such as age, race, income, education level and comorbidities . Additionally, patients may believe that antibiotics promotes faster recovery from the pathology and may therefore specifically seek such prescriptions from their doctor , and the unsubstantiated demand for these medications could lead to bias in the treating physician’s diagnostic and therapeutic process. Furthermore, the large number of prescriptions for systemic medications to treat conjunctivitis is noteworthy given that these drugs be reserved for adjuvant therapy for conjunctivitis derived from sexually transmitted infections . Finally, the absence of updated guidelines for the management of patients with conjunctivitis could contribute to the incorrect diagnosis and inadequate treatment of this pathology .
Another relevant aspect of this report was the large proportion of patients who received ophthalmic glucocorticoids, which are not recommended for the management of most cases of infectious conjunctivitis [8, 11]. However, they can be used in short cycles for refractory cases of allergic and atopic conjunctivitis [8, 9]. It is striking that almost 30.0% of the patients received antibiotics, which is consistent with other studies, such as those reported by De Loof et al in Belgium (30.5%) , and is higher than that reported by Shekhawat et al in a study of more than 340,000 American patients, 20.0% of whom concomitantly used glucocorticoids and antibiotics , and by Yu et al in China, where this association was present in 17.5% of cases . The use of ophthalmic glucocorticoids should be limited due to the risk of complications and adverse drug reactions, since they increase the latency period of adenoviruses, prolong the course of viral conjunctivitis, aggravate herpes simplex virus infections, increase intraocular pressure and increase the risk of glaucoma and cataracts [1, 8, 9, 27, 28] Therefore, due to the need for strict monitoring, these drug combinations should exclusively use by ophthalmologists and health personnel who have the necessary equipment to detect and prevent adverse eye reactions.
Some limitations in the interpretation of the results are recognized, since medical records were not accessed to verify the diagnosis of conjunctivitis or its etiology (allergic, infectious, other), severity and complications. Similarly, medications that the patients may have received that were prescribed outside the health system or were not delivered by the dispensing company were unknown. In addition, it is possible that some of the systemic prescriptions were used for pathologies other than conjunctivitis; however, these pathologies were not identified among the primary and secondary diagnoses listed in the database. However, the study included a significant number of patients who were distributed throughout most of the national territory and were covered by both the contributory and subsidized regimes of the country’s health system.
With these findings, we can conclude that different types of conjunctivitis are being managed without following the recommendations of clinical practice guidelines. The results highlight the extensive use of antibiotics with ophthalmic glucocorticoids, which in many cases can be considered potentially inappropriate prescriptions. It is suggested that those responsible for health care and training provide continuing education measures and develop clinical practice guidelines specifically aimed at first-line health personnel, such as general practitioners, to promote better diagnostic processes and the more careful selection of available medications to reduce the risk of adverse drug reactions and the rates of antimicrobial resistance.