Evaluation of Pharmacodynamic Interactions between Medicinal Plants and Drugs in Patients with Chronic Diseases in South Brazil

The use of medicinal plants is a longstanding practice in several civilizations. However, with the advances in conventional medicine the use of medicinal plants has been interfering with drug therapy. In view of this interaction, the present study evaluated through questionnaires 58 chronically ill patients users of medicinal plants in south Brazil. The interactions between drugs and medicinal plants were compiled from literature data. There were 9 types of possible pharmacodynamic interactions that recurred 85 times among patients. The most commonly used plants were Cymbopogon citratus and Matricaria recutita, interacting mainly with central nervous system targeting drugs, antihypertensives and anticoagulants possibly leading to increased sedation and coagulation disorders.