[The same agent, no response upon restart: tachyphylaxis with psychotropic medications].

Background: This scoping review focuses on the occurrence of tachyphylaxis, defined as reduced responsiveness upon reinitiating a previously effective medication. This phenomenon is previously documented in antidepressants and mood stabilizers.

Aim: To explore the frequency, treatment strategies, and predictability of tachyphylaxis across all psychotropic medications.

Method: The review adheres to PRISMA-ScR guidelines, employing a PubMed search to identify relevant articles.

Results: A total of 22 articles were included: eleven on mood stabilizers (lithium carbonate), eight on antidepressants (SSRIs and TCAs), and three on antipsychotics (aripiprazole, clozapine, olanzapine, paliperidone, quetiapine, and risperidone). No literature on benzodiazepines was found. The incidence varied (8.3-40.2% for antidepressants, 10.8-43.2% for mood stabilizers), with limited evidence for antipsychotics. Some articles discussed potential mechanisms of action, treatment strategies, and risk factors.

Conclusion: Tachyphylaxis was predominantly reported in mood stabilizers and antidepressants. Indications of tachyphylaxis were noted in antipsychotics, except for clozapine. Clear conclusions were hindered by insufficient methodological research. The scarcity of literature emphasizes the need for further investigation into the prevalence, pathophysiology, and risk factors of tachyphylaxis. Until more clarity emerges, clinicians should consider the risk of tachyphylaxis when discontinuing and restarting mood stabilizers and antidepressants.