Prescribing patterns of antibiotics in Lesotho public health institutions

Abstract

In Lesotho, a relatively poor country, empiric use of antibiotics, rather unsupported by sufficient knowledge of the sensitivities of bacterial pathogens to the agents, is by observation a mainstay of treating infections. Such manners of antibiotic prescribing were witnessed as would not altogether be conducive to appropriate prescribing, contrary to an urge of the World Health Organisation for countries to use antibiotics appropriately as a strategy for curbing bacterial pathogen antibiotic resistance development. The purpose of this study, was to investigate, inter alia, the extent to which antibiotics are appropriately prescribed and to make available baseline information that would assist in the formulation of relevant policies on the judicious use of the drugs. Conducted in three phases and in accordance with its set objective, the study generally investigated the extent to which antibiotics were appropriately prescribed and the impact of antibiotic prescribing on treatment outcomes and related costs identified bacterial pathogens commonly associated with diagnosed infections, made predictions of the clinical effectiveness of antibiotic prescribing for diagnosed infections, identified factors that principally would influence prescribers' manner of prescribing antibiotics and developed procedures to enhance the appropriate selection of antibiotics in the empiric treatment of infections. A novel method based on prescribers' adherence to principles of antibiotic prescribing was developed and used in assessing the appropriateness of antibiotic prescriptions. Data on antibiotic prescriptions were collected prospectively from inpatient and outpatient departments of selected hospitals. Data on bacterial pathogen sensitivities to formulary antibiotics, similarly, were collected retrospectively from records of culture sensitivity test results as kept by microbiology laboratories of study site hospitals. Analysis of data was done to show associations of pathogens with diagnosed infections and their sensitivity patterns to formulary antibiotics. A formula for quantifying the activity and cost characteristics of antibiotics was developed and used in selecting antibiotics most appropriate in the empiric treatment of given infections. A structured questionnaire survey that targeted prescribers at health service areas of study site hospitals and aimed at investigating factors that influence prescribers' manner of antibiotic prescribing was also carried out. Results of the study showed that antibiotics were most often prescribed inappropriately in inpatient departments, as compared to outpatient departments. Appropriate antibiotic prescribing in inpatient departments appear to have a positive impact on treatment outcomes and costs of antibiotic treatment. Ampicillin and metronidazole and ampicillin and co-trimoxazole were observed as the first and second most frequently prescribed antibacterial agents in inpatient and outpatient departments respectively. Pathogens predominantly associated with given infections in inpatient departments of study site hospitals were identified as Staphylococcus aureus for lower respiratory tract, eye, ear, and skin and soft tissue infections; Streptococcus pneumoniae for meningitis; Escherichia coli for ascites and urinary tract infections; and Proteus spp for septicaemia. Between January 2000 and December 2005, substantial increases in resistance to cloxacillin, ampicillin, co-trimoxazole and cefotaxime were noticed for Staphylococcus aureus. Similar increases in the case of co-trimoxazole were observed for E. coli and Klebsiella spp. Among gram-positive cocci, ampicillin demonstrated the highest activities against S. pneumoniae and S. pyogenes. Activity of gentamicin against gramnegative bacilli was largely preserved despite the high rate of prescribing the antibiotic in inpatient departments. A large majority of prescribers prescribe antibiotics commonly whenever they are not sure of the aetiologies of diagnosed cases. A majority of prescribers composed of all qualification categories also lack adequate knowledge in bacteriology and principles of antibiotic prescribing. Shortcomings exist in mechanisms of disseminating results of tests on microbial examination of specimens to prescribers. In line with findings of this study, it is recommended that the Ministry of Health and Social Welfare institute measures aimed at improving antibiotic prescribing in the country's health institutions. It is particularly recommended that policies be formulated with regard to appropriate prescribing of antibiotics; development of user friendly algorithms of infection diagnosis and treatment; improvement of functional capabilities of microbiology laboratories vis a vis the institution of effective information network systems for information dissemination on patterns of microbial resistance to commonly used antibacterial agents; and also the education of prescribers on antibiotic prescribing.