With the combined use of St. John's wort with cyclosporine, warfarin, digoxin, steroid preparations, antiviral agents - HIV protease inhibitorsamprenavir, indinavir, nelfinavir, ritonavir, saquinavir) may reduce their effectiveness.
The drug is able to enhance the photosensitizing effect of other medicines, incl. tetracyclines, sulfonamides, thiazide diuretics, quinolones, piroxicam.