Is it easy to od on digitek or digoxin?

Yes. Yes they are tricky meds, with a small difference between not enough and too much (called a small therapeutic index).
Digoxin. It is very easy to overdose on digoxin. Different people have different sensitivity so that a dig level doesn't always tell you a lot except that there's likely too much drug in the patient. For the paitent it is very important to take the drug as prescribed and no more.