Although I don't recommend taking medications past the expiration date, they really are good for six months past the printed date. That said, Azo cranberry tablets are more of a supplement... and as such are more prone to losing effectiveness than to mutating into anything dangerous.
Taking expired Craneberry pills is not safe and you might suffer some side effects. It is also not advisable to abuse the dosage. You should visit a doctor for more information about the effects of these drugs and for further medical advice.
No and they shouldn't, although that depends on how big the box was. Cranberry pills just start to lose their potency when they expire. Taking too many though could hurt your kidneys. If you start to experience pain, go see your Dr.