Serotonergic synergism: the risks and benefits of combining the selective serotonin reuptake inhibitors with other serotonergic drugs.

It has become common clinical practice to combine the selective serotonin reuptake inhibitors with other serotonergic agents for augmentation or adjunctive purposes. The empirical basis for using these combinations remains limited, but is growing. Also growing is a literature that suggests that even the most apparently benign combinations of serotonergic drugs carry at least some risk of serious pharmacokinetic or pharmacodynamic drug interactions, such as a serotonin syndrome.