Studies in animals and people found no interaction between Nicorandil and Digoxin. Neither medicine was seen to change how the other works or how the body handles it. The leaflet does warn that Nicorandil may add to the effect of other blood-vessel-widening or blood-pressure-lowering medicines, but that warning is not about Digoxin. Still, take both together only as your doctor has advised.
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.