1 interaction related to nortriptyline
St. John's wort induces the liver enzymes (chiefly CYP3A4, via the pregnane X receptor) that help clear nortriptyline, which can lower nortriptyline blood levels and weaken its antidepressant effect. The herb also adds serotonergic activity, which gives an additive, theoretical increase in the risk of serotonin syndrome.