There are a couple of isolated cases of possible
serotonin syndrome, when
mirtazapine was used with fluoxetine and
fluvoxamine, and there is a report of hypomania associated with combined use with sertraline. Restless legs
syndrome occurred with fluoxetine and
mirtazapine. Fluvoxamine markedly increased
plasma levels of
mirtazapine in two cases.
Caution is warranted on concurrent use. Monitor for adverse effects (e.g. oedema, sedation) and be aware that
CNS excitation may occur. Extra caution might be appropriate with
fluvoxamine, since the limited evidence suggests that this might markedly raise
mirtazapine levels. However, this needs confirming.