PHARMACOVIGILANCE AND PUBLIC HEALTH; EVALUATING THE EFFECTIVENESS OF ADVERSE DRUG REACTION REPORTING SYSTEMS IN ONITSHA

CHAPTER ONE INTRODUCTION 1.1 Background to the Study Pharmacovigilance (PV) has emerged as a central pillar of global public health, particularly with the increasing complexity of pharmacotherapy in modern medical practice. The World Health Organization (WHO, 2022) defines pharmacovigilance as the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or other drug-related problems. Its primary aim is to enhance patient safety and ensure the efficacy of pharmaceutical products throughout their life cycle. In low- and middle-income countries such as Nigeria, where regulatory infrastructure is evolving, pharmacovigilance is increasingly vital to safeguard the public from preventable adverse drug reactions (ADRs) (Ogar et al., 2021). The implementation of effective ADR reporting systems plays a fundamental role in achieving these goals. These systems allow health professionals and consumers to report unexpected, harmful, or ineffective responses to drug administration. Effective ADR reporting not only informs national regulatory authorities such as the National Agency for Food and Drug Administration and Control (NAFDAC) but also contributes to global databases managed by the Uppsala Monitoring Centre (Uppsala Reports, 2021). However, challenges such as underreporting, lack of awareness, and limited training among health practitioners persist (Adebowale et al., 2023). This scenario is particularly alarming in high-density urban areas like Onitsha, Anambra State, which serve as commercial and pharmaceutical hubs in southeastern Nigeria. In Nigeria, various pharmacovigilance interventions have been initiated in tertiary hospitals, community pharmacies, and primary health care centers. Despite these efforts, the rate of ADR reporting remains suboptimal. Studies have highlighted gaps in knowledge, attitudes, and practices regarding ADRs among healthcare providers (Ezeuko & Mba, 2022). For example, many practitioners report time constraints, fear of legal repercussions, and lack of feedback mechanisms as deterrents to reporting (Nwankwo et al., 2021). This underreporting may lead to sustained drug-related harm in the population and reduced confidence in the health system. Onitsha, as a vibrant commercial city, presents unique pharmacovigilance challenges due to its large population, high volume of drug transactions, and the proliferation of unregulated drug markets. While there are institutional structures in place for ADR monitoring, their functionality and accessibility for health workers remain under-researched. Moreover, patient literacy, informal dispensing practices, and a lack of digital infrastructure further complicate ADR documentation and reporting. Public health outcomes are directly linked to the strength of pharmacovigilance systems. According to Okonkwo et al. (2022), improved pharmacovigilance correlates with timely regulatory decisions and reduced incidence of adverse drug events. In environments where ADR reporting systems are weak, drugs with harmful side effects may remain in circulation, endangering lives and undermining public trust in medicine. In Onitsha, anecdotal evidence and media reports point to several instances of suspected ADRs that went unreported or unresolved due to structural and systemic failures in the local health network. As Nigeria scales up its digital health infrastructure and aligns with international pharmacovigilance protocols, it becomes imperative to conduct localized assessments of ADR reporting mechanisms. By focusing on Onitsha, this study seeks to uncover specific challenges and evaluate the effectiveness of existing systems in managing and reporting drug-related problems, thereby contributing to both public health security and regulatory reform. 1.2 Statement of the Problem Despite Nigeria’s adoption of international pharmacovigilance standards and the presence of NAFDAC’s Yellow Card reporting system, the frequency of ADR reporting remains alarmingly low (Adedeji & Lawal, 2021). In Onitsha, where drug use is extensive and sometimes unsupervised, there is a critical gap between drug consumption and effective pharmacovigilance. Many healthcare professionals in the region are either unaware of existing reporting platforms or lack the motivation to utilize them due to inadequate institutional support, feedback, or incentives (Okafor et al., 2023). Several studies have shown that both primary and secondary healthcare providers exhibit poor knowledge and attitudes towards ADR reporting (Uchenna & Adeyemi, 2020). In densely populated cities like Onitsha, where access to medication—both prescription and over-the-counter—is high, such knowledge deficits can translate into serious public health threats. Moreover, the regulatory institutions appear disconnected from the grassroots level of drug consumption and healthcare delivery. These systemic inefficiencies not only hinder early detection of harmful drug reactions but also affect patient outcomes and pharmacoeconomic efficiency. Compounding the problem is the lack of regional data. Most pharmacovigilance studies in Nigeria have focused on major urban centers like Lagos and Abuja, leaving a significant gap in understanding how ADR systems function in southeastern cities such as Onitsha. Without localized data, policy interventions may remain generic and fail to address context-specific issues. This study aims to fill this void by providing empirical evidence on the effectiveness, awareness, and utility of ADR reporting systems in Onitsha, Anambra State. 1.3 Objectives of the Study 1. To assess the level of awareness and knowledge of healthcare professionals in Onitsha about adverse drug reaction reporting systems. 2. To evaluate the utilization and accessibility of existing ADR reporting mechanisms in Onitsha health facilities. 3. To identify barriers hindering effective pharmacovigilance practices in Onitsha. 4. To analyze the implications of underreporting ADRs on public health outcomes in the study area. ________________________________________ 1.4 Research Questions 1. What is the level of awareness and knowledge of ADR reporting among healthcare professionals in Onitsha? 2. How effective and accessible are the current ADR reporting systems in Onitsha? 3. What challenges limit the reporting of ADRs among health providers in the area? 4. What are the public health implications of ineffective ADR reporting in Onitsha? 1.5 Research Hypotheses 1. There is no significant relationship between healthcare professionals' knowledge of ADRs and their use of ADR reporting systems in Onitsha. 2. There is no significant association between the accessibility of ADR reporting platforms and the frequency of ADR reports submitted. 1.6 Significance of the Study This study contributes to the academic and professional discourse by expanding the empirical base for understanding pharmacovigilance at the sub-national level in Nigeria. It offers new insights into the challenges and opportunities for improving ADR reporting systems in a critical pharmaceutical hub like Onitsha. Healthcare providers stand to benefit directly from the findings, as the study will expose training gaps and recommend interventions that can enhance reporting behavior and patient care. By identifying specific institutional, knowledge, and behavioral barriers to ADR reporting, the study will help tailor future capacity-building efforts. At the societal level, improved pharmacovigilance will translate to better patient outcomes, safer drug use, and increased public confidence in the healthcare system. In a city like Onitsha, where the risk of ADRs is elevated due to informal drug markets, these outcomes are particularly urgent. 1.7 Scope of the Study This study is geographically scoped to Onitsha, Anambra State, with a focus on health facilities including public hospitals, private clinics, and community pharmacies. The population comprises licensed healthcare professionals including pharmacists, nurses, and physicians actively involved in patient care and drug administration. Thematically, the study centers on three major variables: knowledge of ADRs, utilization of ADR reporting systems, and public health outcomes. It explores both the institutional mechanisms and individual behaviors that affect the pharmacovigilance system in the study area. 1.8 Operational Definition of Terms 1. Pharmacovigilance: The scientific activities involved in the detection, assessment, and prevention of adverse effects related to drug use. 2. Adverse Drug Reaction (ADR): Any harmful or unintended response to a drug that occurs at normal doses for prophylaxis, diagnosis, or therapy. 3. ADR Reporting System: Institutional platforms, such as NAFDAC's Yellow Card Scheme, designed for the documentation and communication of drug reactions. 4. Public Health Outcome: The health effects on a population resulting from practices related to medication safety, including morbidity and mortality from ADRs.