Background. Globally, pharmacovigilance activities were affected by COVID-19. Therefore, several competent health authorities around the world, including several countries in the Middle East, have issued guidelines and practices to ensure that pharmacovigilance activities are maintained and continued during the pandemic. Objective. The aim of this study was to assess the impact of COVID-19, preparedness and performance of national pharmacovigilance systems in participating countries during COVID-19 pandemic. Methods. This was a cross- sectional study that was conducted between July and October 2020. National pharmacovigilance centres in 18 Arab countries in the Middle East were invited to participate in this study. Descriptive analysis was used to summarize and present the results of this study. Results. Responses were obtained from 14 (77.8%) Arab countries. Ten of participating countries (71.4%) have either specific national PV guidelines or local PV practices during the COVID-19 pandemic. Adverse events reporting was the main PV activity that was covered by PV guidelines and practices. National guidelines and practices covered other PV activities in 8 (57.14%) of the participating countries. Performance and practices of national PV centres vary considerably among participating countries during the pandemic. Conclusion. The findings highlight the differences in preparedness and performance of different national PV centres in participating Middle Eastern countries. Improving digital infrastructure among participating countries could serve as a useful tool to minimize the impact of the pandemic on PV activities.

Background: Warfarin, a commonly prescribed oral anticoagulant, relies on maintaining effective therapeutic levels as measured by the time within therapeutic range (TTR) and international normalized ratio (INR). However, the narrow therapeutic index of warfarin, influenced by both genetic and non-genetic factors, poses a significant risk of bleeding or coagulation complications. Identifying predictors of stable INR levels in warfarin-naïve patients is crucial to improve treatment safety and efficacy. Methods: This retrospective study conducted between 2018 and 2021 at Queen Alia Hospital Institute QAHI – RMS aimed to identify the impact of patient demographics, co-morbidities, and drug-drug interactions on stable, sub-therapeutic, and supra-therapeutic INR readings. Additionally, the study sought to determine risk factors for warfarin toxicity and major bleeding events associated with warfarin treatment. Results: Medical records of 163 warfarin-naïve patients (103 males, 60 females) with a baseline INR ≤1.2 were analyzed. Patients were admitted as emergency cases or transferred from internal medicine to the warfarin clinic. The majority of patients were under 65 years of age, overweight, and received warfarin for heart valve replacement or atrial fibrillation. Polypharmacy was common among the patients. Analysis revealed both good responders (24.5%) and poor responders (75.5%) in terms of TTR%. Conclusion: Predictors of warfarin anticoagulation may include age, gender, smoking status, and concomitant medication use. Considering these factors when managing warfarin therapy can improve treatment outcomes and patient safety.