You must wean from it or you get get vicious heart rates, and high BP spikes and a terribly anxious feeling from the excess adrenaline.
Probably a week or two at half dosage and then another at quarter dosage is close to the way to do it.
Some people can do it faster, some need more time.
Check your heart-rate...keep it under 100 unless you are exercising.
I think Lenin misunderstood - I believe he is talking about stopping Toprol. You should be able to just quit Lotrel. However, keep in mind, that you are really dropping two drugs with that one. Neither will have a rebound effect. But, your BP most likely will go up when you drop it.