Drug interactions leading to serious adverse effects are to be cautiously watched for when multiple drugs are used simultaneously. (1) It is important for the physician to be aware of these interactions. Although in many instances the adverse interaction does not reach a magnitude of recognizable clinical expression, rarely it can result in a serious adverse outcome.

Adverse drug interactions may lead to increased toxicity, decreased efficacy or both. The possibility of interaction with non-prescription drugs, herbal or alternative medicines or food should also be borne in mind. (2) Increased risk of drug induced toxicity or therapeutic failure can occur when a new drug is ...