The
plasma levels of amitriptyline can be reduced by
St John's wort (Hypericum perforatum) and nortriptyline seems to be similarly affected. Other
tricyclics are also expected to interact.
Both the
tricyclics and St John's wort are antidepressants, but whether the final sum of this interaction is more or less antidepressant activity is not known. Monitor antidepressant
efficacy if St John's wort is given with any tricyclic.