Introduction: There are no published studies on adverse drug reactions (ADRs) as a cause of inpatient treatment for Brazilian patients. Although the Dose-Time Sensitivity Classification System has been shown to be useful for assessing ADRs in hospitalized patients. Objective: We analyzed the cases of hospitalization due to drug poisoning attending the hospitals. Methods: Standardized cases reports of 47 patients undergoing clinical therapy in hospital Padre Albino and Emilio Carlos from 2010 to 2015 were used as data collection tool to support this investigation. Results: A total 47 patients were admitted to the hospitals for exogenous intoxication, 81%, of these patients, had at least one ADR as the cause of hospital admission, with a total of a single drug reaction. The mean age of patients who experienced ADRs was about 42.31 years, among patients with ADRs, 39% were female, (47.13years), and male (39.17years). None of the women were pregnant. Conclusions: We found that the patients took between 1 and 6 medicatins and the reason for hospitalization of these patients in the countryside of the Brazil was the ADRs incidence. Our results is in the agreement with previously reported by other coutries.