Venlafaxine can almost double
haloperidol levels. Adverse effects resulting from this interaction have been seen in practice. A retrospective study found that
venlafaxine caused a 27% increase in
olanzapine levels. The concurrent use of
aripiprazole with
venlafaxine has led to adverse effects such as the neuroleptic malignant
syndrome and extrapyramidal
symptoms.
Monitor the outcome closely, being alert for the need to reduce the
haloperidol dosage. The
clinical significance of the raised
olanzapine levels is unclear. Be awareof the possibility of an interaction between
aripiprazole and
venlafaxine if adverse effects become troublesome.