Background: There was a fluctuation in medication demand and supply during COVID-19 pandemic. This study aimed to assess the trend of drug utilisation in Malaysia in 2018-2022 and evaluate the impact of COVID-19 on drug utilisation rates., Methods: We conducted a repeated cross-sectional study of pharmaceutical sales data from public and private sectors in Malaysia from 2018 to 2022. Drug utilisation rates for the period after the onset of COVID-19 (2020-2022) was compared with the earlier period (2018-2019). Interrupted time-series regression analyses evaluated level and slope changes compared to pre-COVID-19 pandemic level for quarterly rates of drugs utilisation in public and private sectors., Results: There was an immediate reduction in the utilisation rates for all drugs after COVID-19 in public (-20.4%; p = 0.043) and private sectors (-22.4%; p = 0.003). In both sectors, significant level changes were observed for anti-infectives, musculoskeletal, neurological, respiratory, and sensory organs preparations following COVID-19 pandemic, followed by a sustained increase in trend from 2020 to 2022. Public sector had a 22.2% reduction in the utilisation of cardiovascular drugs ( p = 0.002), particularly for renin-angiotensin system (RAS) agents (-47.4%, p = 0.019). Private sector had large changes for anti-infectives (-53.6%, p < 0.001) and neurological drugs (-51.4%, p < 0.001), driven by an immediate level reduction in antibacterials (-54.2%, p < 0.001) and cough and cold preparations (-59.2%, p < 0.001). Classes with agents used for COVID-19 treatment, such as systemic corticosteroids, antibiotics, and antivirals had an increasing trend between April 2020 and December 2022, although some slope changes were not statistically significant., Conclusion: A significant reduction in the overall drug utilisation rates was observed in the public and private sectors in Malaysia as an immediate impact of the COVID-19 pandemic in 2020. The impacts varied by therapeutic class and health sector. This finding provides an understanding of the changing patterns of drug utilisation that were affected by disease outbreaks for future planning of pandemic preparedness., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2024 Ministry of Health Malaysia. Published by Informa UK Limited, trading as Taylor & Francis Group.)