ADVERSE REACTIONS, SOME OF WHICH WERE SERIOUS, HAVE BEEN REPORTED IN PATIENTS WHO HAVE RECENTLY BEEN DISCONTINUED FROM A MONOAMINE OXIDASE INHIBITOR (MAOI) AND STARTED ON ANTIDEPRESSANTS. CONCURRENT USE OF AN NSAID OR ASPIRIN MAY POTENTIATE THIS RISK OF BLEEDING. ALTERED ANTICOAGULANT EFFECTS, INCLUDING INCREASED BLEEDING, HAVE BEEN REPORTED WHEN SSRIS AND SNRIS ARE COADMINISTERED WITH WARFARIN. CONCOMITANT USE OF PRISTIQ WITH POTENT INHIBITORS OF CYP3A4 MAY RESULT IN HIGHER CONCENTRATIONS OF PRISTIQ. CONCOMITANT TREATMENT OF PRISTIQ WITH A 5-HT RECEPTOR AGONISTS WARRANT CAREFUL OBSERVATION OF THE PATIENT FOR SERIOUS DRUG INTERACTIONS LIKE SEROTONIN SYNDROME OR MALIGNANT NEUROLEPTIC SYNDROME. CONCOMITANT USE OF PRISTIQ WITH SEROTONIN PRECURSORS (SUCH AS TRYPTOPHAN) IS NOT RECOMMENDED.