Polypharmacy is increasingly common in the prevention and treatment of diseases in animals. Drug-drug interactions represent one common event associated with multidrug therapy that may interfere with optimal clinical outcome. Mechanisms whereby drugs may interact during concurrent treatment are well established for many drug combinations. However, the incidence and clinical relevance of interactions are difficult to determine with accuracy because of the many factors involved and because there is very little clinical data to validate in vitro findings. Therefore, the need for clarification of the clinical relevance of potential interactions has become crucial, since clinicians are faced with the difficult task of evaluating both qualitatively and quantitatively the risk of drug interactions in their patients in order to make sound therapeutic decisions. An understanding of the role of pharmacokinetics, pharmacodynamics, and the factors that alter these processes are vital in the clinician's process of decision making.

Objectives of The Presentation

     1. To briefly review common mechanisms of drug-drug interactions.
     2. To discuss sources of uncertainty in the clinical setting.
     3. To review some relevant interactions in small animals.