Additive adverse effects on psychomotor skills and sedation have been reported with
diazepam and
mirtazapine.
Patients should be warned that the sedative effects of
benzodiazepines in general may be potentiated by concurrent use with
mirtazapine. Note that the US manufacturer actually recommends that patients taking
mirtazapine avoid the use of
diazepam and similar drugs, but this is probably overly cautious.