Drug-drug Interactions in Psychiatric Practice, Part 4: Classification of Neuropsychiatric Medications Based on Their Principal Mechanisms of Action (With Updated Neuroscience-based Nomenclature).

This column is the fourth in a series exploring drug-drug interactions (DDIs) with a special emphasis on psychiatric medications. This column discusses how drugs with multiple mechanisms of action have the potential to interact pharmacodynamically by the mechanism(s) mediating their therapeutic indication and for some drugs by other mechanisms (ie, drugs with multiple mechanisms of action). In this and the next column in this series, we present a classificatory system in the form of 2 tables that prescribers can use to predict the action of a neuropsychiatric drug when used alone as well as DDIs that can occur when it is used in combination with other drugs. The table in this column presents neuropsychiatric medications classified according to their mechanism(s) of action. The next column in this series will present a parallel table summarizing major types of pharmacodynamic DDIs based on mechanism of action and discuss strategies for minimizing adverse outcomes from such unintended DDIs. The authors recommend that health care providers' knowledge of the drugs they frequently prescribe include both their generic and brand names (to avoid confusion leading to dispensing the wrong drugs), routinely used doses, pharmacokinetics including half-lives, pharmacodynamics including mechanism(s) of action and binding profile for specific receptor(s) (not specifically discussed here but available in other columns by the first author), adverse effect profiles, potential DDIs, and the evolving research literature on these agents.