With the joint application of St. John's Wort preparations with warfarin, digoxin, cyclosporine, steroid drugs, antiviral (HIV) agents (amprenavir, indinavir, nevirapine, nelfinavir, ritonavir, saquinavir, efavirenz) may reduce their effectiveness. The use of the drug may enhance the photosensitizing effect of other drugs, including piroxicam, sulfonamides, tetracyclines, thiazide diuretics, quinolones.
It is possible to increase the antidepressant effect of monoamine oxidase inhibitors, with an increased risk of their side effects.When combined with fluoxetine, paroxetine, sertraline, fluvoxamine or citalopram, weighting of the hemolytic
reactions and the course of "serotonin syndrome" (dizziness, nausea, vomiting, headache, epigastric pain, anxiety, confusion, confusion, anxiety and irritability). It is possible to reduce the hypotensive effect of reserpine and the concentration of cyclosporine in the blood. When used concomitantly with ethinylestradiol and desogestrel, the risk of bleeding may increase. It is possible to accelerate the metabolism of theophylline.