Drug therapy has an effect on the management of patients in dentistry. Many drugs produce oro-dental problems; in addition concurrent medication can interact with drugs which the dentist may prescribe. The aim of this dictionary is to draw together the effects of drugs on the teeth, oral and perioral structures and highlight drug interactions which impact on dental treatment. Drugs taken by outpatients which may be encountered in general dental practice and interactions with drugs contained in the Dental Practitioners Formulary have been included. Interactions which may occur with medication prescribed by dentists working in the hospital service have also been covered. Drugs which the dentist may prescribe have been.