Effect of interacting nonsteroidal anti-inflammatory agents (NSAIDs) and opioids on mood: pharmacodynamic considerations in misuse and abuse

Clinical reality shows that pharmacodynamic interactions, as well as the pharmacokinetic interactions, might be used to increase effectiveness when treatment resistance to monotherapy presents. Nonsteroidal anti-inflammatory agents and opioids are among the most common drugs used in clinical practice to treat a heterogeneous spectrum of conditions, ranging from inflammation and fever to pain. Both classes of drugs appear to have mood-altering effects. Thus, their use, individually or concomitant, might determine an alteration of the clinical course of mood disorders, with the manifestation of which might be more severe in those patients who present comorbid substance use disorders and therefore are more prone to abusing/misusing these treatments. In this chapter we aim to provide a series of pharmacodynamic considerations concerning the interacting effects of nonsteroidal anti-inflammatory agents and opioids, and identify the implications of this pharmacodynamic synergism on mood and on the risk of developing abuse and misuse.