Healthcare professionals, contrary to what is known, more frequently encounter adverse drug reactions during clinical practice. Irrespective from spontaneous reporting of pharmacovigilance system, these professionals, particularly physicians, should solve these problems immediately. However, at first they have to evaluate the causal relationship between adverse events and drugs and then initiate the necessary therapeutic interventions. If physicians ignore the potential roles of medications in the etiology of complaints of patients and instead prescribe new drugs towards new treatment goals, new adverse events would be unavoidable. Therefore, the presence of adverse drug reactions should always be questioned correctly and, if necessary, the patient's well-being should be ensured by essential changes in the treatment protocol. In this review, types of adverse drug reactions, principles regarding causality assessment and basic treatment approaches are outlined.