Aim: To examine the effects of drug use in the last 6 months before contracting coronavirus disease-2019 (COVID-19) on the clinical course of COVID-19. Methods: In this retrospective cohort study, which included 525 patients diagnosed with COVID-19 between March and November 2020 from four different family health centers in Istanbul, the records of the patients were retrospectively analyzed. In addition to demographic information, all medications used by the patients in the last 6 months before the diagnosis of COVID-19 were noted. The effects of demographic data and medications on the three main endpoints of the study, which were hospitalization, intensive care unit (ICU) admission, and mortality, were analyzed by using logistic regression models. Results: Of the 525 COVID-19 patients included in the study, 109 (20.8%) were hospitalized, 18 (3.4%) were treated in ICU, and 11 (2.1%) patients died. While increasing age is associated with hospitalization, ICU admission and mortality; also, the presence of COVID-19 thoracic computed tomography (CT) findings and polypharmacy were associated with an increased hospitalization; living alone and the presence of COVID-19 thoracic CT findings were associated with an increased ICU admission. When adjusted for age and comorbidity, logistic regression models revealed that medications for diabetes mellitus (DM) increased the probability of hospitalization (OR=3.9, 95% CI 1.2-13.0), and calcium channel blockers (CCBs) increased the probability of ICU admission (OR=15.8, 95% CI 2.1-120.2) and mortality (OR=295.1, 95% CI 4.6-18946.6). Conclusion: Previously utilization of DM medications and CCBs may have negative effects on the clinical course of COVID-19.