This retrospective cross-sectional study aims to evaluate the safety, tolerability, and adherence of patients prescribed Nirmatrelvir-ritonavir (Paxlovid) in outpatient settings, focusing on its use in managing category 2 COVID-19 patients across three primary healthcare clinics in Selangor, Malaysia. Data were collected from the Paxlovid pharmacy registry and medical records at Klinik Kesihatan Seksyen 7, Klinik Kesihatan Seksyen 19, and Klinik Kesihatan Kelana Jaya between April 1, 2022, and November 30, 2022. This study analysed data from 415 category 2 COVID-19 patients aged ≥ 18years. The primary and secondary outcomes included the assessment of patient demographics, Paxlovid dosing, current medication, changes in drug regimen, adherence, and adverse drug reactions (ADR). Pharmacists follow-ups were conducted on days 3 and 5 post-medication initiation. The majority (79.5%) of the cohort experienced ADR, predominantly dysgeusia, diarrhoea, body ache, vomiting, and nausea. Despite this, the ADRs were generally well-tolerated, with no severe impacts reported. High adherence was observed, with 96.9% of patients completing the 5-day regimen. The primary reasons for non-adherence included adverse effect intolerability, dosing ambiguity, forgetfulness, concerns about ADR, and perceived health improvement. Notable medications interacting with Paxlovid were simvastatin, amlodipine, and atorvastatin, and 21.7% of 23 concurrent medications were found not to comply with the recommended interventions by the University of Liverpool COVID-19 Drug Interaction database. Paxlovid demonstrates a high level of safety and tolerability in outpatient COVID-19 patients, with optimal adherence observed. This study underscores the vital role of healthcare professionals in managing Paxlovid within primary healthcare and highlights the need for broader research and direct patient involvement to enhance treatment strategies against COVID-19.