Drug and diet interactions: avoiding therapeutic paralysis.

An explosion of information about drug and diet interactions has greatly complicated and confused the use of antidepressant drugs, yet if clearly understood, such information will actually enhance the safety and efficacy of these medications. The background against which antidepressants are discussed includes an overview of the cytochrome P450 (CYP) system (which now contains over 500 P450 genes), the concepts of enzyme specificity and selectivity, the roles of genetics and nonpharmacologic environmental factors, and examples of beneficial and detrimental drug and diet interactions. The comparative profiles of the various antidepressants are then presented with consideration given to their roles as substrates, inhibitors, and inducers of P450 enzymes such as CYP1A2, 2B6, 2C, 2D6, and 3A4. Examples of clinically important antidepressant drug/drug and drug/diet interactions are provided.