Epimedium sagittatum, Maca Root & others may react badly with phenytoin, along with warfarin, amitriptyline, cyclosporine, nitrates, estrogen, clarithromycin, erythromycin and any medicine that lowers blood pressure.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.